Patent Application
20230210735
The present invention relates to compounds and methods for personal body odor control. More specifically, the present invention relates to compounds and methods to prevent, reduce, and/or ameliorate old person smell.
Old person smell is a characteristic aroma that occurs in middle aged and elderly people as the result of degradation of lipid hydroperoxides in their skin, releasing primarily the compound 2-nonenal (see S. Haze et al, J. Invest. Dermatol. 116: 520-524 2001), and perhaps other lipid oxidation products. The method described herein describes use in on-skin applications such as soaps, shampoos, deodorants, body creams and lotions, etc.; specifically for the purpose of reducing the unpleasant “old person smell.”
The present invention provides a benefit over fragrances that merely cover-up a body odor, such as old person smell, with an applied fragrance that is more pleasant and overwhelms the malodor. Using the invention described herein, the chemical compounds that create the malodor are prevented from forming, reduced in intensity, and/or ameliorated.
Suitable compounds for preventing, reducing, and/or ameliorating old person smell according to the present invention include:
an α-oxocarboxylic acid, an organic ammonium salt of an α-oxocarboxylic acid, an inorganic salt of the α-oxocarboxylic acid, a thiol, sulphur-containing peptides, sulphur-containing proteins, phosphorylated ascorbic acid analogues, ascorbate esters, ascorbic acid salts, oxalic acid monoesters, oxalic acid monoester salts, silane hydride compounds, diesters of oxaloacetic acid, salts of diesters of oxaloacetic acid, glyoxylic acid, and salts of glyoxylic acid;
hydrolysable esters of 2-oxoacids. glyoxylic acids, and/or oxalic acids to produce a controlled and/or extended in-situ release of a 2-oxoacid, oxalic acid monoester, or oxalic acid via chemical or enzymatic hydrolysis/cleavage; and-2-hydroxyketones, such as acetoin or analogues with longer carbon chains, for the purpose of reacting with and chemically consuming organic hydroperoxides, or esters of 2-hydroxyketones that could chemically or enzymatically hydrolyze/cleave to produce 2-hydroxyketones in-situ. 2-hydroxyketones are not ionic compounds, and so can be advantageously soluble in hydrophobic matrices. 2-hydroxyketones with extended carbon chains, for example 2-hydroxy-3-oxo-hexadecane, have good solubility in hydrophobic matrices by virtue of their hydrophobicity e.g., an alkyl chain of eight to eighteen carbons containing the 2-hydroxyketone group.
The present invention provides a method for preventing, reducing, or ameliorating a skin odor from a person caused by oxidation of skin lipids via hydroperoxide intermediates, which comprises administering to the skin of a person a compound selected from the group consisting of: an α-oxocarboxylic acid, an organic ammonium salt of an α-oxocarboxylic acid, an inorganic salt of the α-oxocarboxylic acid, a thiol, sulphur-containing peptides, a sulphur-containing protein, a phosphorylated ascorbic acid analogue, an ascorbate ester, an ascorbic acid salt, an oxalic acid monoester, an oxalic acid monoester salt, a silane hydride compound, a diester of oxaloacetic acid, a salt of a diester of oxaloacetic acid, a glyoxylic acid, a salt of glyoxylic acid, a 2-hydroxyketone, a hydrolysable ester of a 2-oxoacid, a hydrolysable ester of an oxalic acid or glyoxylic acid, a hydrolyzable ester of a 2-hydroxyketone, and combinations thereof.
In an aspect of the invention, the skin odor caused by oxidation of skin lipids via hydroperoxide intermediates is old person smell.
A thiol according to the present invention may be a glutathione, N-acetylcysteine methyl ester, or cysteine ethyl ester hydrochloride.
In one aspect, the ascorbate ester is ascorbyl palmitate. In a further aspect, the ascorbate salt is triethanolammonium ascorbate.
A salt of the diester of oxaloacetic acid may be the diethyloxaloacetate sodium salt.
In another aspect of the invention, the salt of glyoxylic acid is triethanolamine glyoxylate.
According to the present invention, the α-oxocarboxylic acid can be selected from pyruvic acid, 2-oxovaleric acid, phenylglyoxylic acid, 2-oxobutyric acid, 2-oxo-2-furanacetic acid, oxaloacetic acid, α-ketoglutaric acid, 2-oxopentandioate, indole-3-pyruvic acid, 2-thiopheneglyoxylic acid, trimethylpyruvic acid, 2-oxoadipic acid, 4-hydroxyphenylpyruvic acid, phenylpyruvic acid, 2-oxooctanoic acid, and mixtures thereof.
According to the present invention, the hydrolysable ester of a 2—oxoacid or an oxalic acid, or a glyoxylic acid, or a 2-hydroxyketone may be an aryl or an alkyl ester.
In an aspect of the present invention, the hydrolysable ester of a 2-oxoacid or a hydrolysable ester of an oxalic acid may be selected from Di-n-Butyl α-Ketoglutarate, Di-tert-Butyl α-Ketoglutarate, Dibenzyl α-Ketoglutarate, Dimethyl Oxalate, Dibutyl Oxalate, Diethyl Oxalopropionate, Diethyl Oxalopropionate, Diethyl α-Ketoglutarate, and combinations thereof.
In aspects of the present invention, the 2-hydroxyketone comprises an alkyl chain of 8 to 18 carbons and a 2-hydroxyketone group.
In one aspect, the 2-hydroxyketone is 2-hydroxy-3-oxo-hexadecane.
The present invention includes a method for preventing, reducing or ameliorating old person smell, which comprises administering to the skin of a person at risk for or having old person smell a product containing a suitable compound of the present invention to prevent, reduce, or ameliorate old person smell; wherein the product is selected from the group: soap, a shampoo, a bodywash, a body or scalp spray, a perfume, and a rub-in/leave-on skincare product.
In certain aspects, the rub-in/leave-on skincare product is a lotion, a gel, or a cream.
In aspects of the present invention, a suitable compound to prevent, reduce, or ameliorate old person smell is 0.01 to 10.0% w/w of the product or 0.1 to 0.5% w/w of the product.
The present invention encompasses a consumer product for preventing, reducing or ameliorating old person smell, such as:
The present invention provides a method for reducing the level of 2-nonenol on a person's skin comprising contacting the person's skin with a compound selected from the group consisting of: an α-oxocarboxylic acid, an organic ammonium salt of an α-oxocarboxylic acid, an inorganic salt of the α-oxocarboxylic acid, a thiol, sulphur-containing peptides, a sulphur-containing protein, a phosphorylated ascorbic acid analogue, an ascorbate ester, an ascorbic acid salt, an oxalic acid monoester, an oxalic acid monoester salt, a silane hydride compound, a diester of oxaloacetic acid, a salt of a diester of oxaloacetic acid, a glyoxylic acid, a salt of glyoxylic acid, a 2-hydroxyketone, a hydrolysable ester of a 2-oxoacid, or glyoxylic acid, or a oxalic acid, or a 2-hydroxyketone, and combinations thereof.
While an article of clothing is being worn, sweat and oils from the skin of the wearer can be transferred to and absorbed by the article of clothing. By autoxidation, bacterial action, or enzymatic action, the skin lipids which become deposited onto the cloth can be oxidized to intermediate hydroperoxides that further decompose to release malodorous aldehydes and other compounds. This can lead to body odor for the wearer.
In another aspect of the invention, the clothes of a person can be protected from developing malodors formed by autoxidation of the wearer's skin lipids, via inclusion of a hydroperoxide scavenging reagent into a laundry care product. The hydroperoxide scavenging agent can deposit onto the clothes during the washing process, the drying process, or by any other means, and will neutralize lipid hydroperoxides as they form on the treated article of clothing, thereby preventing, reducing, or ameliorating the malodor.
Suitable compounds (hydroperoxide scavenging agents) for preventing, reducing, and/or ameliorating old person smell or other malodors on clothing according to the present invention include:
an α-oxocarboxylic acid, an organic ammonium salt of an α-oxocarboxylic acid, an inorganic salt of the α-oxocarboxylic acid, a thiol, sulphur-containing peptides, sulphur-containing proteins, phosphorylated ascorbic acid analogues, ascorbate esters, ascorbic acid salts, oxalic acid monoesters, oxalic acid monoester salts, silane hydride compounds, diesters of oxaloacetic acid, salts of diesters of oxaloacetic acid, glyoxylic acid, and salts of glyoxylic acid;
hydrolysable esters of 2-oxoacids. glyoxylic acids, and/or oxalic acids to produce a controlled and/or extended in-situ release of a 2 oxoacid, glyoxylic acid, oxalic acid monoester, or oxalic acid via chemical or enzymatic hydrolysis/cleavage; and
-2-hydroxyketones, such as acetoin or analogues with longer carbon chains, for the purpose of reacting with and chemically consuming organic hydroperoxides, or esters of 2 hydroxyketones that could chemically or enzymatically hydrolyze/cleave to produce 2 hydroxyketones in-situ. 2-hydroxyketones are not ionic compounds, and so can be advantageously soluble in hydrophobic matrices. 2-hydroxyketones with extended carbon chains, for example 2-hydroxy-3-oxo-hexadecane, have good solubility in hydrophobic matrices by virtue of their hydrophobicity e.g., an alkyl chain of eight to eighteen carbons containing the 2 hydroxyketone group.
The present invention further provides uses for preventing, reducing or ameliorating old person smell.
In the following description, reference is made to specific embodiments which may be practiced, which is shown by way of illustration. These embodiments are described in detail to enable those skilled in the art to practice the invention described herein, and it is to be understood that other embodiments may be utilized and that logical changes may be made without departing from the scope of the aspects presented herein. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the various aspects presented herein is defined by the appended claims.
The Abstract is provided to comply with 37 C.F.R. § 1.72(b) to allow the reader to quickly ascertain the nature and gist of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
The present invention is useful for controlling the production of volatile aldehydic or other lipid autoxidation products responsible for a characteristic malodor in middle-aged or elderly people, called “old person smell.” Old person smell is caused by degradation/autoxidation of fats/oils endogenously contained in the skin of humans, which produces volatile, unpleasant smelling compounds such as 2-nonenal. The effects/products of autoxidation are mitigated by chemical consumption of reactive lipid hydroperoxide intermediates formed in the autoxidation process. In addition to old person smell, the invention can also be useful for controlling any other volatile body odor compounds that arise from oxidation of lipids or other components in the skin, that form via hydroperoxide intermediates.
The chemical composition, intensity and pleasantness of natural body smell changes during a lifetime. It is known that elderly people have a specific body odor, sometimes described as “nursing home smell” or “old person smell.” 2-nonenal may be responsible for the characteristic body smell of elderly and middle-aged people. Mogilnicka, et al., Int. J. Mol. Sci. 2020;21,2886.
Many formulated perfumes, body care products, homecare products, perfumery raw materials (such as, for example, essential oils, natural extracts, and synthetic ingredients) can undergo oxidation, resulting in the formation of chemical species including peroxides, organic hydroperoxides, peroxyhemiacetals. In addition, many food raw materials, such as, for example, fats and oils, or derivatives thereof, are known to undergo an autoxidation process that results in the formation of the intermediate chemical species glyceride hydroperoxides. The glyceride hydroperoxides may further degrade into aldehydes and ketones. Without intending to be limited to any particular theory the autoxidation process may result in an unpleasant and unpalatable rancidity of the food raw material.
The peroxide value (POV), defined as the amount of equivalents of oxidizing potential per 1 kilogram of material is an indication of the extent of the oxidation. The POV of formulated perfumes, body care products, homecare products, cosmetic products, and perfumery raw materials is subject to regulatory limits due to skin sensitization issues, such as, for example, contact dermatitis. For example, an unacceptably high POV can result in a perfumery raw material failing quality control testing, and therefore being deemed unusable. In another example an unacceptably high POV can result in a food raw material, or a formulated food product (also referred to herein as a flavored article, nutritional supplement) having a rancid taste.
Skin exposure may be the result of an incidental exposure (such as, for example, of a hard surface cleaner or a hand dishwashing soap when the user does not wear a pair of gloves when using the product). Alternatively, skin exposure may be the result of a long-term, or intentional exposure (such as, for example, of a shampoo, or skin moisturizer).
As used herein, the term “peroxide value” or “POV” refers to the amount of equivalents of oxidizing potential per 1 kilogram of material. Without intending to be limited to any particular theory, the POV of a material is determined analytically. The term “POV” does not refer to a chemical compound or group of compounds but is often used loosely and interchangeably with the products of autoxidation within a sample that cause a response during a POV test. These autoxidation products differ depending upon the particular material being tested. Many classes of chemical compounds will produce a response during a POV test, including but not limited to organic and inorganic hydroperoxides, organic and inorganic peroxides, peroxyhemiacetals, peroxyhemiketals, and hydrogen peroxide itself.
By way of illustration, one POV test is an iodometric oxidation-reduction titration. All POV-responsive compounds share the property that they are capable of oxidizing the iodide ion to molecular iodine within the time period specified for the test; in fact, the iodide oxidation reaction is the basis for the test. Thus, “POV” is a numerical value that represents the molar sum total of the all the iodide-oxidizing species in a particular sample.
By way of illustration, limonene and linalool are unsaturated terpenes commonly found as major components in many essential oils. Both limonene and linalool are easily oxidized by atmospheric oxygen to form hydroperoxides. The hydroperoxides of limonene and linalool are known to be sensitizers capable of causing contact dermatitis. Consequently, limonene, and natural products containing limonene may only be used as perfumery raw materials when the recommended organic hydroperoxide level is below 20 mmol/L (or 10 mEq/L). Similarly, essential oils and isolates derived from the Pinacea family, including Pinus and Abies genera may only be used as perfumery raw materials when the recommended organic hydroperoxide level is below 10 mmol/L (or 5 mEQ/L).
By way of another illustration, fats and oils, or derivatives thereof, are known to undergo an autoxidation process that leads to unpleasant and unpalatable rancidity. Without intending to be limited to any particular theory, glyceride hydroperoxides are an intermediate chemical species in the autoxidation process, which further degrade into aldehydes and ketones that produce the rancid aroma.
The POV of a perfumery raw material may be determined by any method readily selectable by one of ordinary skill in the art. Non-limiting examples include, iodometric titration, high-performance liquid chromatography, and the like.
An example of a method for determining the POV of a perfumery raw material is disclosed in Calandra et al., Flavour and Fragr. J. (2015), 30, p 121-130.
Perfumery raw materials include, but are not limited to essential oils, natural extracts, and synthetic ingredients.
The POV of a formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material may be determined by any method readily selectable by one of ordinary skill in the art. Non-limiting examples include, iodometric titration, high-performance liquid chromatography, and the like.
An example of a method for determining the POV of a formulated perfume is disclosed in Calandra et al., Flavour and Fragr. J. (2015), 30, p 121-130.
The POV of a formulated body care product may be determined by any method readily selectable by one of ordinary skill in the art. Non-limiting examples include iodometric titration, high-performance liquid chromatography, and the like.
An example of a method for determining the POV of a formulated body care product is disclosed in Calandra et al., Flavour and Fragr. J. (2015), 30, p 121-130.
Without intending to be limited to any particular theory, the POV of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is reduced by treating the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material with at least one remediant. The at least one remediant reacts with the organic hydroperoxide thereby consuming the organic hydroperoxide, reducing the organic hydroperoxide's oxidative potential.
As used herein, the term “remediant” refers to an agent that is capable of reducing the POV of a formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. The POV is reduced by treating the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material, and/or reducing lipid hydroperoxides that are formed by autoxidation. The remediant may also react with and remove rancid-smelling aldehydes that result from the decomposition of lipid hydroperoxides.
For example, by way of illustration, the POV of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is reduced by treating the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material with an α-oxocarboxylic acid. The α-oxocarboxylic acid reacts with the organic hydroperoxide via oxidative decarboxylation, thereby consuming the organic hydroperoxide, reducing the organic hydroperoxide's oxidative potential. The resulting reaction results in the oxidation of the α-oxocarboxylic acid to carbon dioxide and the corresponding carboxylic acid containing one less carbon atom, and the reduction of the organic hydroperoxide to its corresponding organic alcohol. An exemplar proposed reaction, using pyruvic acid as the α-oxocarboxylic acid and limonene-hydroperoxide as the organic hydroperoxide is depicted in
Accordingly, one aspect presented herein, provides a method:
Alternatively, one aspect presented herein provides a method,
One aspect presented herein, provides a method:
Alternatively, one aspect presented herein, provides a method:
Alternatively, one aspect presented herein provides a method,
One aspect presented herein, provides a method:
In one aspect, the method is performed at room temperature. In one aspect, the method is performed at a temperature ranging from −20 degrees Celsius to 78 degrees Celsius.
In one aspect the perfumery raw material is selected from the group consisting of a synthetic ingredient, a natural product, an essential oil, and a natural extract.
In one aspect, the perfumery raw material is citrus oil.
In one aspect, the body care product is a skin cream.
In one aspect, the perfumery raw material is treated prior to the incorporation into a perfume.
In one aspect, the perfumery raw material is treated after the incorporation into a perfume.
In one aspect, the pre-determined second lower level is between 5 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 19 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 18 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 17 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 16 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 15 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 14 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 13 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 12 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 11 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 10 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 9 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 8 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 7 mmol/L. In an alternate aspect, the pre-determined second lower level is between 5 and 6 mmol/L.
In one aspect, the pre-determined second lower level is between 6 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 7 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 8 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 9 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 10 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 11 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 12 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 13 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 14 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 15 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 16 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 17 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 18 and 20 mmol/L. In an alternate aspect, the pre-determined second lower level is between 19 and 20 mmol/L.
In one aspect, the pre-determined second lower level is 20 mmol/L. In an alternate aspect, the pre-determined second lower level is 19 mmol/L. In an alternate aspect, the pre-determined second lower level is 18 mmol/L. In an alternate aspect, the pre-determined second lower level is 17 mmol/L. In an alternate aspect, the pre-determined second lower level is 16 mmol/L. In an alternate aspect, the pre-determined second lower level is 15 mmol/L. In an alternate aspect, the pre-determined second lower level is 14 mmol/L. In an alternate aspect, the pre-determined second lower level is 13 mmol/L. In an alternate aspect, the pre-determined second lower level is 12 mmol/L. In an alternate aspect, the pre-determined second lower level is 11 mmol/L. In an alternate aspect, the pre-determined second lower level is 10 mmol/L. In an alternate aspect, the pre-determined second lower level is 9 mmol/L. In an alternate aspect, the pre-determined second lower level is 8 mmol/L. In an alternate aspect, the pre-determined second lower level is 7 mmol/L. In an alternate aspect, the pre-determined second lower level is 6 mmol/L. In an alternate aspect, the pre-determined second lower level is 5 mmol/L. In an alternate aspect, the pre-determined second lower level is 4 mmol/L. In an alternate aspect, the pre-determined second lower level is 3 mmol/L. In an alternate aspect, the pre-determined second lower level is 2 mmol/L. In an alternate aspect, the pre-determined second lower level is 1 mmol/L. In an alternate aspect, the pre-determined second lower level is less than 1 mmol/L.
In one aspect, the pre-determined second lower level is a 10% reduction in the POV. In an alternate aspect, the pre-determined second lower level is a 20, or 30, or 40, or 50, or 60, or 70, or 80, or 90, or 100% reduction in the POV.
Without intending to be limited to any particular theory, the reduction, prevention, and/or inhibition of the oxidation increases, enhances, and/or improves the stability and/or shelf life of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
Without intending to be limited to any particular theory, reducing the POV of a flavored article, nutritional supplement or a food raw material, prevents, reduces, or inhibits the formation of the intermediate glyceride hydroperoxides in the flavored article, nutritional supplement or the food raw material. Reducing, or inhibiting, or preventing the formation of the intermediate glyceride hydroperoxides in the flavored article, nutritional supplement or the food raw material may prevent, reduce, or delay the development of rancidity in the flavored article, nutritional supplement or the food raw material.
Without intending to be limited to any particular theory, the at least one remediant may react with and consume lipid hydroperoxides that are formed by autoxidation, and/or react with and consume rancid-smelling aldehydes that result from the decomposition of the lipid hydroperoxides.
Without intending to be limited to any particular theory, and by way of illustration, the reaction of the at least one α-oxocarboxylic acid with autoxidized triglycerides appears to occur via two distinct and independent pathways. The first pathway is the reductive decarboxylation of lipid hydroperoxides by the at least one α-oxocarboxylic acid. This may result in the formation of the corresponding lipid alcohol and causes lowering of the POV (peroxide value). Additionally, this may also prevent the further development of organoleptic rancidity, because the lipid hydroperoxides are no longer available to decompose into rancidity-causing aldehydes. Without intending to be limited to any particular theory, it is these aldehydes that are perceived as a rancid odor; the lipid hydroperoxides themselves do not have a perceivable odor and therefore do not directly contribute to rancid, unpleasant aroma.
The development of rancidity is therefore a two-step process; first, the autoxidation of an unsaturated lipid to an odorless lipid hydroperoxide, followed by the second step, which is decomposition of the lipid hydroperoxides to form rancid smelling aldehydes. By consuming the intermediate lipid hydroperoxides before they can decompose to rancid smelling aldehydes, the development of rancidity can be prevented.
The second pathway is the reduction in concentration of rancid smelling aldehydes. The at least one α-oxocarboxylic acid may also react directly with rancid smelling aldehydes to form a less odorous adduct, thereby consuming the aldehydes and lowering their concentration. The result is a reduction of the rancid smell in the treated oil, constituting a remediation of already rancid oil. Treatment of triglycerides by the at least one α-oxocarboxylic acid is detailed in Example 36 below.
A flavored article, nutritional supplement includes, for example, a food product (e.g., a beverage), a sweetener such as a natural sweetener or an artificial sweetener, a pharmaceutical composition, a dietary supplement, a nutraceutical, a dental hygienic composition and a cosmetic product. The flavored article, nutritional supplement may further contain at least one flavoring.
In some aspects, the at least one flavoring may further modify the taste profile or taste attributes of the flavored article, nutritional supplement.
In some aspects, the flavored article, nutritional supplement is a food product including, for example, but not limited to, fruits, vegetables, juices, meat products such as ham, bacon and sausage, egg products, fruit concentrates, gelatins and gelatin-like products such as jams, jellies, preserves and the like, milk products such as ice cream, sour cream and sherbet, icings, syrups including molasses, corn, wheat, rye, soybean, oat, rice and barley products, nut meats and nut products, cakes, cookies, confectioneries such as candies, gums, fruit flavored drops, and chocolates, chewing gums, mints, creams, pies and breads.
In some aspects, the food product is a beverage including, for example, but not limited to, juices, juice containing beverages, coffee, tea, carbonated soft drinks, such as COKE and PEPSI, non-carbonated soft drinks and other fruit drinks, sports drinks such as GATORADE and alcoholic beverages such as beers, wines and liquors.
A flavored article, nutritional supplement may also include prepared packaged products, such as granulated flavor mixes, which upon reconstitution with water provide non-carbonated drinks, instant pudding mixes, instant coffee and tea, coffee whiteners, malted milk mixes, pet foods, livestock feed, tobacco, and materials for baking applications, such as powdered baking mixes for the preparation of breads, cookies, cakes, pancakes, donuts and the like.
A flavored article, nutritional supplement may also include diet or low-calorie food and beverages containing little or no sucrose. Flavored article, nutritional supplements may also include condiments such as herbs, spices and seasonings, flavor enhancers (e.g., monosodium glutamate), dietetic sweeteners and liquid sweeteners.
In some aspects, the flavored article, nutritional supplement is a pharmaceutical composition, a dietary supplement, a nutraceutical, a dental hygienic composition or a cosmetic product.
Dental hygiene compositions are known in the art and include, for example, but not limited to, a toothpaste, a mouthwash, a plaque rinse, a dental floss, a dental pain reliever (such as ANBESOL) and the like. In some aspects, the dental hygiene composition includes one natural sweetener. In some aspects, the dental hygiene composition includes more than one natural sweetener. In some aspects, the dental hygiene composition includes sucrose and corn syrup, or sucrose and aspartame.
In some aspects, a cosmetic product includes, for example, but not limited to, a face cream, a lipstick, a lip gloss and the like. Other suitable cosmetic products of use in this disclosure include a lip balm, such as CHAPSTICK or BURT'S BEESWAX Lip Balm.
An alternate aspect presented herein, provides a method for increasing the shelf life of a food raw material, comprising the steps of: adding at least one remediant selected from the group consisting of: an α-oxocarboxylic acid, an organic ammonium salt of the α-oxocarboxylic acid, an inorganic salt of the α-oxocarboxylic acid, a thiol, sulphur-containing peptides, sulphur-containing proteins, phosphorylated ascorbic acid analogues, ascorbate esters, ascorbic acid salts, oxalic acid monoesters, oxalic acid monoester salts, silane hydride compounds, diesters of oxaloacetic acid, salts of diesters of oxaloacetic acid, glyoxylic acid, and salts of glyoxylic acid to the food raw material having a first POV level; and mixing or placing in contact with the at least one remediant into the food raw material for a time sufficient to reduce the first POV level to a pre-determined second lower level. Without intending to be limited to any particular theory, the reduction of the first POV level to a pre-determined second lower level prevents, reduces, or inhibits the formation of the intermediate glyceride hydroperoxides in the food raw material, resulting in the prevention, reduction, inhibition of the development of rancidity in the food raw material.
An alternate aspect presented herein, provides a method for increasing the shelf life of a food raw material, comprising the steps of: adding at least one α-oxocarboxylic acid to the food raw material having a first POV level; and mixing or placing in contact with the at least one α-oxocarboxylic acid into the food raw material for a time sufficient to reduce the first POV level to a pre-determined second lower level. Without intending to be limited to any particular theory, the reduction of the first POV level to a pre-determined second lower level prevents, reduces, or inhibits the formation of the intermediate glyceride hydroperoxides in the food raw material, resulting in the prevention, reduction, inhibition of the development of rancidity in the food raw material.
Without intending to be limited to any particular theory, the food raw material may be employed as a solvent for a flavoring ingredient, or, alternatively, the food raw material itself may be a flavoring ingredient.
An alternate aspect presented herein, provides a method for increasing the shelf life of flavored article, nutritional supplement, comprising the steps of: adding at least one remediant selected from the group consisting of: an α-oxocarboxylic acid, an organic ammonium salt of the α-oxocarboxylic acid, an inorganic salt of the α-oxocarboxylic acid, a thiol, sulphur-containing peptides, sulphur-containing proteins, phosphorylated ascorbic acid analogues, ascorbate esters, ascorbic acid salts, oxalic acid monoesters, oxalic acid monoester salts, silane hydride compounds, diesters of oxaloacetic acid, salts of diesters of oxaloacetic acid, glyoxylic acid, and salts of glyoxylic acid to the flavored article, nutritional supplement having a first POV level; and mixing or placing in contact with the at least one remediant into the flavored article, nutritional supplement for a time sufficient to reduce the first POV level to a pre-determined second lower level. Without intending to be limited to any particular theory, the reduction of the first POV level to a pre-determined second lower level prevents, reduces, or inhibits the formation of the intermediate glyceride hydroperoxides in the flavored article, nutritional supplement, resulting in the prevention, reduction, inhibition of the development of rancidity in the flavored article, nutritional supplement.
An alternate aspect presented herein, provides a method for increasing the shelf life of flavored article, nutritional supplement, comprising the steps of: adding at least one α-oxocarboxylic acid to the flavored article, nutritional supplement having a first POV level; and mixing or placing in contact with the at least one α-oxocarboxylic acid into the flavored article, nutritional supplement for a time sufficient to reduce the first POV level to a pre-determined second lower level. Without intending to be limited to any particular theory, the reduction of the first POV level to a pre-determined second lower level prevents, reduces, or inhibits the formation of the intermediate glyceride hydroperoxides in the flavored article, nutritional supplement, resulting in the prevention, reduction, inhibition of the development of rancidity in the flavored article, nutritional supplement.
In one aspect, the food raw material is selected from the group consisting of a fat, an oil, or a derivative thereof. In one aspect, the derivative thereof is selected from the group consisting of a monoglyceride, a diglyceride, and a phospholipid. In one aspect, the phospholipid is selected from the group consisting of a lecithin, a phosphatidyl ethanolamine, and a modified triglyceride.
In one aspect, the food raw material is treated prior to the incorporation into a flavored article, nutritional supplement. In an alternate aspect the food raw material is incorporated after the incorporation into a flavored article, nutritional supplement.
In one aspect, the food raw material is a cooking oil. Examples of cooking oils suitable for treatment according to the aspects described herein include, but are not limited to: olive oil, palm oil, soybean oil, canola oil (rapeseed oil), corn oil, peanut oil, other vegetable oils, and animal-based oils, such as, for example, butter or lard.
In one aspect, the method is performed at room temperature. In one aspect, the method is performed at a temperature ranging from −20 degrees Celsius to 78 degrees Celsius.
In one aspect, the pre-determined second lower level is between 0 and 6 mmol/L. In an alternate aspect, the pre-determined second lower level is between 0 and 5 mmol/L. In an alternate aspect, the pre-determined second lower level is between 0 and 4 mmol/L. In an alternate aspect, the pre-determined second lower level is between 0 and 3 mmol/L. In an alternate aspect, the pre-determined second lower level is between 0 and 2 mmol/L. In an alternate aspect, the pre-determined second lower level is between 0 and 1 mmol/L.
In one aspect, the pre-determined second lower level is between 1 and 6 mmol/L. In an alternate aspect, the pre-determined second lower level is between 2 and 5 mmol/L. In an alternate aspect, the pre-determined second lower level is between 3 and 5 mmol/L. In an alternate aspect, the pre-determined second lower level is between 4 and 5 mmol/L.
In one aspect, the pre-determined second lower level is 5 mmol/L. In an alternate aspect, the pre-determined second lower level is 4 mmol/L. In an alternate aspect, the pre-determined second lower level is 3 mmol/L. In an alternate aspect, the pre-determined second lower level is 2 mmol/L. In an alternate aspect, the pre-determined second lower level is 1 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.9 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.8 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.7 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.6 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.5 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.4 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.3 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.2 mmol/L. In an alternate aspect, the pre-determined second lower level is 0.1 mmol/L. In an alternate aspect, the pre-determined second lower level is 0 mmol/L.
In one aspect, the pre-determined second lower level is a 10% reduction in the POV. In an alternate aspect, the pre-determined second lower level is a 20, or 30, or 40, or 50, or 60, or 70, or 80, or 90, or 100% reduction in the POV.
In one aspect, the at least one remediant has FEMA-GRAS status.
In one aspect, the at least one α-oxocarboxylic acid has FEMA-GRAS status. In one aspect, the at least one α-oxocarboxylic acid is selected from the group consisting of: pyruvic acid, 2-oxovaleric acid, phenylglyoxylic acid, 2-oxobutyric acid, 2-oxo-2-furanacetic acid, oxaloacetic acid, α-ketoglutaric acid, 2-oxopentandioate, indole-3-pyruvic acid, 2-thiopheneglyoxylic acid, trimethylpyruvic acid, 2-oxoadipic acid, 4-hydroxyphenylpyruvic acid, phenylpyruvic acid, 2-oxooctanoic acid, and mixtures thereof.
The term “salts” as applied to the anions of 2-oxoacids, oxalic acids, oxalic acid monoesters, glyoxylic acids, etc. as used herein can mean any cationic moiety including but not limited to: inorganic salts comprising metallic cations such as lithium, sodium, potassium, magnesium, calcium, iron, copper, zinc, ammonium cation (NH4+), etc. Cations derived from protonation of organic amines, including but not limited to N-monoalkyl, N,N-dialkyl, N,N,N-trialkyl, N-monoaryl, N.N-diaryl, N,N,N-triaryl amines, or any combination thereof, including N-aryl and/or N-alkyl substituents that contain further substitution, such as triethanolamine, N-methyl diethanolamine, etc. Cations derived from complete substitution of amines, including but not limited to N,N,N,N-tetraalkyl, N,N,N,N-tetraaryl, or any combination thereof including N-aryl and/or N-alkyl substituents that contain further substitution, such as tetraethanolamine, N-methyl triethanolamine, etc. Cations derived from amino acids such as arginine, ornithine, or proteins or peptides that contain basic amino acids, or metabolites such as creatine. uric acid, etc. Cations derived from nitrogen containing polymers, either synthetic or natural, such as chitosan. Nitrogen containing heterocycles, in which the nitrogen(s) are contained within the ring, or in which the nitrogen(s) are contained on ring substituents, including any nitrogen containing alkaloid such as caffeine, etc. Or any combination of the moieties mentioned above.
In some aspects, the at least one α-oxocarboxylic acid is added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material as a salt. The salt may be formed by reacting the at least one α-oxocarboxylic acid with an organic base.
In the aspects where the at least one α-oxocarboxylic acid is a mono-acid, the resultant salt may be a mono-salt. In the aspects where the at least one α-oxocarboxylic acid is a di-acid, the resultant salt may be a mono-salt, or a di-salt.
Examples of suitable organic bases include but are not limited to the organic bases described in Examples 7-11 below, polymeric amines, polyethylenimines, and the like.
Alternatively, the salt comprises an anion of at least one α-oxocarboxylic acid and a cation selected from the group consisting of: Nat, Mg2+, and Ca2+.
An example of an ammonium salt includes the ammonium salt formed by reacting the at least one α-oxocarboxylic acid with N-methyl diethanolamine.
In some aspects, the molar ratio of the at least one α-oxocarboxylic acid to N-methyl diethanolamine may be 1:2, or 1:1, or 2:1.
In some aspects, the ammonium salt of the at least one α-oxocarboxylic acid possesses surfactant properties. Without intending to be limited to any particular theory, surfactant properties typically arise in molecules that contain an ionic and/or highly polar functional groups in the molecule, along with one or more spatially separated, long hydrophobic section(s). If a hydrophobic moiety, such as an alkyl group with a sufficient number of carbons (for example, C-8 to C-24) is bound to the ammonium salt of the at least one α-oxocarboxylic acid, the resulting molecule may demonstrate surfactant properties.
Without intending to be limited to any particular theory, an ammonium salt of the at least one α-oxocarboxylic acid possessing surfactant properties, or that is ionic and highly polar may be useful in a variety of home care and body care consumer products that come in contact with the user's skin during use.
Examples of ammonium salts of the at least one α-oxocarboxylic acid having surfactant properties include but are not limited to: the diammonium salt made from alpha-ketoglutaric acid and N, N-dimethyldodecylamine in a 1:2 molar ratio, and the monoammonium salt made from alpha-ketoglutaric acid and N, N-dimethyldodecylamine in a 1:1 molar ratio.
In some aspects, the ammonium salt of the at least one α-oxocarboxylic acid possesses emollient properties. Without intending to be limited to any particular theory, emollient properties typically arise in molecules that are predominately hydrophobic and inert with low melting points (relative to body temperature) can act as emollients. Useful emollients have oily or grease-like physical properties, and act as softening agents and/or moisture barriers when applied to the skin. While the ammonium salt of the at least one α-oxocarboxylic acid listed above are ionic and highly polar in character, if a sufficient quantity of hydrophobic moieties can be incorporated into an ammonium salt of the at least one α-oxocarboxylic acid, the resulting molecule may display emollient characteristics.
One approach is to use an amine that has three long, hydrophobic or oily substituents as the base component of the ammonium salt of the at least one α-oxocarboxylic acid. Such a molecule may have hydroperoxide consuming/POV lowering qualities along with emollient properties, and therefore provide additional benefits to the user. These would be useful in a variety of body care consumer products that are placed onto the skin during use and left on for extended periods for purposes of moisturizing, protecting, or softening the user's skin.
Examples of ammonium salts of the at least one α-oxocarboxylic acid having emollient properties include, but are not limited to: the diammonium salt made from alpha-ketoglutaric acid and Tris[2 (2 (methoxyethoxy)ethyl]amine in a 1:2 molar ratio.
In some aspects, the at least one α-oxocarboxylic acid may be reacted with N-methyl diethanolamine by dissolving the at least one α-oxocarboxylic acid in a solvent, such as, for example, acetone, and adding N-methyl diethanolamine to the solution. The resultant opaque, white emulsion may then be vortexed, during which time a second phase may coalesce. The mixture may then be placed in a freezer for at least 30 minutes, causing the bottom phase to thicken to a waxy solid. While still cold, the top layer may then be easily removed via decantation and discarded. Residual acetone may be removed from the bottom product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature, thereby resulting in a faint yellow, highly viscous oil at room temperature comprising the diammonium salt.
Other compounds suitable to form an ammonium salt via reaction with the at least one α-oxocarboxylic acid include, 2-(dimethylamino)ethanol, and N, N-dimethyldodecylamine.
In one aspect the salt is an ammonium salt formed by reacting the α-oxocarboxylic acid with a compound selected from the group consisting of: 2-(dimethylamino)ethanol, N, N-dimethyldodecylamine, Tris [2 (2 (methoxyethoxy)ethyl]amine, and N-methyl diethanolamine.
Without intending to be limited to any particular theory, the ammonium salt of the at least one α-oxocarboxylic acid may prevent acid-catalyzed chemical reactions from occurring that can harm and/or degrade the treated formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. Alternatively, the ammonium salt of the at least one α-oxocarboxylic acid may improve the solubility of the at least one α-oxocarboxylic acid. Alternatively, the ammonium salt of the at least one α-oxocarboxylic acid may provide an emulsifying effect.
Without intending to be limited to any particular theory, a salt of the at least one α-oxocarboxylic acid, when added to an aqueous system comprising the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material may be an emulsifier. Such a composition may be useful for salad dressings, marinades, sauces, and the like.
In one aspect, the ammonium salt of the at least one α-oxocarboxylic acid may be further combined with at least one other agent. In one aspect, the at least one other agent is chitosan.
In one aspect, alpha-ketoglutaric acid is added to a mixture of palmitic acid and chitosan. Such a composition may be an emulsifier for the food oil in an aqueous system, and may be useful for salad dressings, marinades, sauces, and the like.
In one aspect the salt of the at least one α-oxocarboxylic acid is an ornithine or a creatine salt.
In one embodiment, the thiol is selected from the group consisting of: glutathione, N-acetylcysteine methyl ester, and cysteine ethyl ester hydrochloride.
In one embodiment, the ascorbate ester may be ascorbyl palmitate.
In one embodiment, the ascorbate salt may be triethanolammonium ascorbate.
In one embodiment, the salt of the diester of oxaloacetic acid may be diethyloxaloacetate, sodium salt.
In one embodiment, the salt of glyoxylic acid may be triethanolamine glyoxylate.
In one aspect, the time sufficient to reduce the POV to a pre-determined second lower level is 30, or or 29, or 28, or 27, or 26, or 25, or 24, or 23, or 22, or 21, or 20, or 19, or 18, or 17, or 16, or 15, or 14, or 13, or 12, or 11, or 10, or 9, or 8, or 7, or 6, or 5, or 4, or 3, or 2, or 1 day(s).
In one aspect, the time sufficient to reduce the POV to a pre-determined second lower level is greater than 24 hours. In one aspect, the time sufficient to reduce the POV to a pre-determined second lower level is 48, or 47, or 46, or 45, or 44, or 43, or 42, or 41, or 40, or 39, or 38, or 37, or 36, or 35, or 34, or 33, or 32, or 31, or 30, or 29, or 28, or 27, or 26, or 25, or 24, or 23, or 22, or 21, or 20, or 19, or 18, or 17, or 16, or 15, or 14, or 13, or 12, or 11, or 10, or 9, or 8, or 7, or 6, or 5, or 4, or 3, or 2, or 1 hour(s).
In one aspect, the time sufficient to reduce the POV to a pre-determined second lower level is 60 minutes or less. In one aspect, the time sufficient to reduce the POV to a pre-determined second lower level is 60, or 50, or 40, or 30, or 20, or 10, or 9, or 8, or 7, or 6, or 5, or 4, or 3, or 2, or 1 minute.
Without intending to be limited to any particular theory, the amount of the α-oxocarboxylic acid and/or the rate at which the α-oxocarboxylic is added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is controlled to ensure that an excess of the α-oxocarboxylic does not accumulate. An excess accumulation of the α-oxocarboxylic may result, for example, in acid-catalyzed damage to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
The amount of the α-oxocarboxylic acid that is added to the formulated perfume, body care product, perfumery raw material, flavored article, nutritional supplement, or food raw material is dependent on several factors, including, but not limited to, the stability of the α-oxocarboxylic acid in solution, the solubility of the α-oxocarboxylic acid in the formulated perfume, body care product, perfumery raw material, flavored article, nutritional supplement, or food raw material, the pKa of the α-oxocarboxylic acid, the rate of reduction of the POV, the effect the α-oxocarboxylic acid has on the olfactive properties and/or taste of the formulated perfume, body care product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
By way of illustration, pyruvic acid, phenylpyruvic acid, and 2-oxovaleric acid possess strong aromas are used as FEMA-GRAS flavoring components. In these aspects, the intrinsic odors of the α-oxocarboxylic acid may alter or be incompatible with the organoleptic quality of a formulated perfume, for example.
An alternative to using an odorless α-oxocarboxylic acid in the aspects described herein is the use of an α-oxocarboxylic acid that is compatible with the fragrance of the perfume, and when consumed by reaction with hydroperoxides, that also liberates a carboxylic acid that is compatible with the fragrance. By way of illustration, indole-3-pyruvic acid nay be used to reduce the POV of a fragrance that has an indolic character (i.e. contains perceivable amounts of indole and/or skatole).
Examples of an α-oxocarboxylic acid that is odorless include α-ketoglutaric acid. Without intending to be limited to any particular theory, an odorless α-oxocarboxylic acid may reduce the POV of a formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material with a lower impact on the organoleptic properties of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material, compared to an α-oxocarboxylic acid that has an odor.
The solubility of the α-oxocarboxylic acid may change if the composition comprising the α-oxocarboxylic acid is formulated differently. Using α-ketoglutaric acid as an example, the solubility of the α-oxocarboxylic acid may be low in a perfume raw material such citrus oil. However, the solubility of the α-oxocarboxylic acid may increase, if the perfume raw material is added to a hydroalcoholic perfume base (a solution comprising from 80% to 90% ethanol in water). In these aspects, if the α-oxocarboxylic acid is a strong acid, the amount of the α-oxocarboxylic acid in solution in the hydroalcoholic perfume base may have to be limited, to prevent alterations of the organoleptic properties on the perfume raw materials or the formulated perfume due to the acid-catalyzed degradation of the perfume raw material.
Examples of aspects where the α-oxocarboxylic acid may be unstable in solution include oxaloacetic acid, which is unstable in aqueous solution. In these aspects, the oxaloacetic acid breaks down to pyruvic acid, and carbon dioxide. In these aspects, reduction of the POV of the formulated perfume, body care product, perfumery raw material, flavored article, nutritional supplement, or food raw material may be via the oxaloacetic acid, the pyruvic acid, or any combination thereof.
In some aspects, the solubility of the α-oxocarboxylic acid in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is low. By way of illustration, at the lower limit of solubility, the α-oxocarboxylic acid may be practically insoluble in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. In contrast, at the upper limit of solubility, the α-oxocarboxylic acid may be fully miscible in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
Examples of aspects where the solubility of the α-oxocarboxylic acid in formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is low include, but are not limited to pyruvic acid in citrus oil. In these aspects, the α-oxocarboxylic acid may be added at a concentration in excess of the solubility, thus forming a two-phase system, wherein one phase consists of the α-oxocarboxylic acid. Without intending to be limited to any particular theory, components of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material may partition into the phase consisting of the α-oxocarboxylic acid. Exposure of the components of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material to the phase consisting of the α-oxocarboxylic acid may result in chemical changes/damage to acid-sensitive compounds in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
By way of illustration, essential oils are composed largely of terpene compounds. As a class, terpenes are generally subject to acid-catalyzed rearrangements. Consequently, exposure of the components of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material to the phase consisting of the α-oxocarboxylic acid may result in chemical changes/damage to acid-sensitive compounds in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material, and consequently alter the organoleptic properties of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
Consequently, in some aspects presented herein, the α-oxocarboxylic acid is added at a rate that minimizes, or prevents the formation of the second phase consisting of the α-oxocarboxylic acid. Such rate of addition may be equal to the rate of the chemical reaction that reduces the POV of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. Without intending to be limited to any particular theory, addition of the α-oxocarboxylic acid at the same rate as the chemical reaction may prevent the α-oxocarboxylic acid from accumulating and thereby keep the second phase volume minimized, which will reduce partitioning of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material into the highly acidic phase consisting of the α-oxocarboxylic acid.
Alternatively, effective dispersion of the α-oxocarboxylic acid into the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material may increase the rate of the chemical reaction that reduces the POV of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material, by increasing the surface area of contact between the two phases of the two phase system.
Examples of aspects where the solubility of the α-oxocarboxylic acid in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is not low include, but are not limited to 2-oxo-valeric acid. Without intending to be limited to any particular theory, in aspects where the solubility of the α-oxocarboxylic acid in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is not low may result in the formation of a single phase. Here, the added α-oxocarboxylic acid is soluble in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material being treated, and therefore will be diluted immediately upon addition. In this case, if the rate of addition is close to the rate of reaction, the α-oxocarboxylic acid will also be consumed as it is being added. The concentration of the α-oxocarboxylic acid will remain low, and acid-induced changes will be minimized.
In an alternate aspect, the concentration of un-reacted α-oxocarboxylic acid is minimized by using a buffer, wherein the α-oxocarboxylic acid is present as a deprotonated anion.
The anionic form of an α-oxocarboxylic acid will likely be unreactive toward a hydroperoxide relative to the protonated, acidic form. However, as the acidic form is consumed by reaction with hydroperoxides, the equilibrium of the α-oxocarboxylic acid-base pair will quickly reestablish itself in accordance with the pKa of α-oxocarboxylic acid; the anionic form will instantly capture a proton from the media to produce more of the hydroperoxide-reactive acidic form of the α-oxocarboxylic acid. In this way, the bulk acidity of the media can be maintained at a mild pH level, one that will not cause acid damage to the components of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. But simultaneously, there will be a relatively low but fixed level of the α-oxocarboxylic acid in the reactive protonated form, replenished as soon as it is consumed from a sink of the relatively inert anionic form.
For example, using pyruvic acid for illustrative purposes only, pyruvic acid has a pKa of 2.50, buffering the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material to pH 5.5 (a difference of 3 log units), would result in 103 (or 1000) times the concentration of pyruvate anion, compared to pyruvic acid (as per the Henderson-Hasselbalch equation).
In one aspect, the concentration of the α-oxocarboxylic acid ranges from 0.001 to 10 weight percent, after addition to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. In one aspect the concentration of the α-oxocarboxylic acid is 10 weight percent, after addition to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. Alternatively, the concentration of the α-oxocarboxylic acid is 9, or 8, or 7, or 6, or 5, or 4, or 3, or 2, or 1, or 0.9, or 0.8, or 0.7, or 0.6, or 0.5, or 0.4, or 0.3, or 0.2, or 0.1, or 0.09, or 0.08, or 0.07, or 0.06, or 0.05, or 0.04, or 0.03, or 0.02, or 0.01, or 0.009, or 0.008, or 0.007, or 0.006, or 0.005, or 0.004, or 0.003, or 0.002, or 0.001 weight percent, after addition to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
The α-oxocarboxylic acid can be added directly to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material, or, alternatively, the α-oxocarboxylic acid can be diluted prior to addition to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. Any diluent that may be used in perfumery may be used. Suitable diluents include, but are not limited to isopropanol, ethanol, diglyme, triethyleneglycol, and the like. The α-oxocarboxylic acid may be diluted 1:1, or 1:2, or 1:3, or 1:4, or more with the diluent.
Without intending to be limited by any particular theory, the choice of diluent may also influence the amount of the α-oxocarboxylic acid that may be added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. In addition, the choice of diluent may also influence the rate at which the α-oxocarboxylic acid that is be added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. For example, by way of illustration, using pyruvic acid as the α-oxocarboxylic acid, and ethanol as the solvent, the pyruvic acid must be added in an amount, and/or a at a rate that minimizes the formation of an ester with the ethanol.
The α-oxocarboxylic acid can be added to any volume of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. For example, the α-oxocarboxylic acid can be added can be added to 1000 ml of formulated perfume, body care product, or perfumery raw material, or 900, or 800, or 700, or 600, or 500, or 400, or 300, or 200, or 100, or 90, or 80, or 70, or 60, or 50, or 40, or 30, or 20, or 10, or 9, or 8, or 7, or 6, or 5, or 4, or 3, or 2, or 1 ml of formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
In one aspect, the α-oxocarboxylic acid may be added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material over 80 minutes. Alternatively, the α-oxocarboxylic acid may be added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material over 70, or 60, or 50, or 40, or 30, or 20, or 10, or 9, or 8, or 7, or 6, or 5, or 4, or 3, or 2, or 1 minute(s).
In one aspect, the α-oxocarboxylic acid is added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material at a rate of 0.25 ml per minute. In some aspects, the rate of addition is greater than 0.25 ml per minute. In some aspects, the rate of addition is less than 0.25 ml per minute.
In some aspects, the rate at which the α-oxocarboxylic acid is added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is constant. In some aspects, the rate at which the α-oxocarboxylic acid is added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material varies. In one aspect, the α-oxocarboxylic acid is added to the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material at a rate equal to the rate at which the α-oxocarboxylic acid is oxidized. In some aspects, the rate at which the α-oxocarboxylic acid is oxidized may be determined by measuring the POV in the treated formulated perfume, body care product, or perfumery raw material. Referring to
In an alternate aspect, the α-oxocarboxylic acid may be added, and subsequently quenched after a period of time. The α-oxocarboxylic acid may be quenched 80 minutes after addition to the substance. Alternatively, the α-oxocarboxylic acid may be quenched 70, or 60, or 50, or 40, or 30, or 20, or 10, or 9, or 8, or 7, or 6, or 5, or 4, or 3, or 2, or 1 minute(s) after addition to the substance.
In one aspect, the method further comprises removing the excess at least one remediant from the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material having the pre-determined second lower POV level.
In one aspect, the excess at least one remediant is removed from the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material via a liquid-liquid extraction.
In one aspect, the method further comprises treating the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material after removing the at least one remediant to reduce the acidity of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
In one aspect, the method further comprises removing the excess α-oxocarboxylic acid from the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material having a POV of a pre-determined second lower level.
In one aspect, the excess α-oxocarboxylic acid is removed from the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material via a liquid-liquid extraction.
In one aspect, the excess α-oxocarboxylic acid is removed from the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material via a liquid-liquid extraction using water.
In one aspect, other byproducts of the reaction that reduces the POV of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material to the pre-determined second lower level are also removed by the liquid-liquid extraction. All byproducts, or, alternatively, a portion of the byproducts may be removed.
In one aspect, the method further comprises treating the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material after removing the excess α-oxocarboxylic acid to reduce the acidity of the substance. In some aspects, the treatment comprises the addition of a buffer, such as, for example, trethanolamine, or N-methyldiethanolamine, and the like.
In one aspect, the substance is treated with a carbonate salt to reduce the acidity of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
In one aspect, the method for reducing the POV of formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material comprises the steps of:
Examples of a method according to the aspect described above can be found in Examples 1 to 4 below.
In some aspects, the second phase of the α-oxocarboxylic acid in the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material is a “leave-in” composition of the α-oxocarboxylic acid. Without intending to be limited to any particular theory, the amount α-oxocarboxylic acid present in the two phases is in equilibrium, and the reduction of POV may result in the α-oxocarboxylic acid moving from the phase consisting of α-oxocarboxylic acid, into the phase containing the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. One example of this aspect is described in Example 5 below.
In some aspects, the “leave-in” composition of the α-oxocarboxylic acid comprises a single phase composition with the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material. In these aspects, the composition further comprises a buffer, wherein the pH is configured to maintain the majority of the α-oxocarboxylic acid present in a non-protonated form, wherein the non-protonated form is incapable of reacting with the chemical species that contribute to the POV of the composition (including peroxides, organic hydroperoxides, peroxyhemiacetals). Without intending to be limited to any particular theory, the amount of the α-oxocarboxylic acid present in non-protonated form is in equilibrium with an amount of the α-oxocarboxylic acid present in protonated form, and the reduction of POV may result in the α-oxocarboxylic acid moving from the non-protonated from to the protonated form. One example of this aspect is described in Example 4 below.
In these instances, the “leave-in” compositions of the α-oxocarboxylic acid is capable of reducing POV for a prolonged period of time.
Accordingly, one aspect presented herein, provides a composition comprising: (a) a formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material, and (b) an α-oxocarboxylic acid, wherein the α-oxocarboxylic acid is present in the composition in an amount sufficient to decrease the POV from a first level to a pre-determined second lower level.
In one aspect, the α-oxocarboxylic acid is present in the composition in an amount sufficient to prevent the pre-determined second lower level from changing with time. The time may be hours, days, weeks, or longer.
One aspect presented herein, provides a composition comprising: (a) a formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material, and (b) an α-oxocarboxylic acid, wherein the α-oxocarboxylic acid is present in the composition in an amount sufficient to reduce, prevent, or ameliorate an increase in the POV of the formulated perfume, body care product, cosmetic product, homecare product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
In one aspect, the concentration of the at least one α-oxocarboxylic acid in the composition ranges from 0.001 to 10 weight percent.
In one embodiment, the thiol is selected from the group consisting of: glutathione, N-acetylcysteine methyl ester, and cysteine ethyl ester hydrochloride.
In one embodiment, the ascorbate ester may be ascorbyl palmitate.
In one embodiment, the ascorbate salt may be triethanolammonium ascorbate.
In one embodiment, the salt of the diester of oxaloacetic acid may be diethyloxaloacetate, sodium salt.
In one embodiment, the salt of glyoxylic acid may be triethanolamine glyoxylate.
In one aspect the salt of the at least one α-oxocarboxylic acid is an ornithine or a creatine salt.
In one aspect, the at least one α-oxocarboxylic acid is selected from the group consisting of: pyruvic acid, 2-oxovaleric acid, phenylglyoxylic acid, 2-oxobutyric acid, 2-oxo-2-furanacetic acid, oxaloacetic acid, α-ketoglutaric acid, 2-oxopentandioate, indole-3-pyruvic acid, 2-thiopheneglyoxylic acid, trimethylpyruvic acid, 2-oxoadipic acid, 4-hydroxyphenylpyruvic acid, phenylpyruvic acid, 2-oxooctanoic acid, and mixtures thereof.
In one aspect, the perfumery raw material is citrus oil.
An example of a composition according to the aspect described above can be found in Example 5 below.
In some aspects, the at least one remediant may be applied to, or incorporated into, or covalently bound to a solid substrate, wherein the solid substrate comprising the at least one remediant is used to treat a formulated perfume, body care product, cosmetic product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
In some aspects, the at least one α-oxocarboxylic acid, or a salt thereof may be applied to, or incorporated into, or covalently bound to a solid substrate, wherein the solid substrate comprising the at least one α-oxocarboxylic acid, or a salt thereof is used to treat a formulated perfume, body care product, cosmetic product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
Any inert, finely divided or high surface area material may be used as the solid support. Examples include, but are not limited to: metals, glass, expanded ceramics, plastics, or inorganic solids. In addition, the solid support may comprise the bottom and/or the walls of a vessel containing the formulated perfume, body care product, cosmetic product, perfumery raw material, flavored article, nutritional supplement, or food raw material.
In some aspects, the solid support has a high surface are: volume ratio. Examples of such solid supports include but are not limited to steel wool. An example of a composition treated according to the aspect employing a solid support as described above can be found in Example 24 below.
Referring to
In some aspects, the linear series comprises “bi-dentate” amine compounds. As used herein, the term “bi-dentate amine compound” refers to an amine compound having two free amine groups capable of forming an ionic bond with a carboxyl group of an at least one α-oxocarboxylic acid.
Referring to
In some aspects, the at least one α-oxocarboxylic acid is selected from the group consisting of: pyruvic acid, 2-oxovaleric acid, phenylglyoxylic acid, 2-oxobutyric acid, 2-oxo-2-furanacetic acid, oxaloacetic acid, α-ketoglutaric acid, 2-oxopentandioate, indole-3-pyruvic acid, 2-thiopheneglyoxylic acid, trimethylpyruvic acid, 2-oxoadipic acid, 4-hydroxyphenylpyruvic acid, phenylpyruvic acid, 2-oxooctanoic acid, and mixtures thereof.
In some aspects, the multi-dentate amine compound is selected from the group consisting of: N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine, 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol, and mixtures thereof.
Other examples of multi-dentate amine compounds suitable for use in the present disclosure include amino acids, polyimine, chitosan, and the like.
Referring to
In some aspects, the linear and/or branched series may comprise a multi-dentate amine compound bound to the at least one α-oxocarboxylic acid via ionic bonds with other moieties, such as, for example, phosphate, or sulphate moieties.
In some aspects, the at least one α-oxocarboxylic acid is incorporated into an aqueous phase of a gel comprising a polymer selected from the group consisting of: gelatin, agarose, alginate, polyacrylamides, acrylates, and combinations thereof.
In some aspects, the gel may be configured to exclude molecules above, or below a certain molecular weight. Examples of such configurations include but are not limited to the formation of branches that are configured to act as a size exclusion filter.
In some aspects, the at least one α-oxocarboxylic acid further comprises an ammonium salt.
In some aspects, the linear and/or branched series of the at least one α-oxocarboxylic acid bonded to an amine compound via ionic bonds further comprises a polymer selected from the group consisting of: gelatin, agarose, alginate, polyacrylamides, acrylates, and combinations thereof. In some aspects, the linear and/or branched series of the at least one α-oxocarboxylic acid bonded to the amine compound via ionic bonds comprises a network incorporating an aqueous phase. In some aspects, the aqueous phase may contain the at least one α-oxocarboxylic acid.
In one aspect, the amine compound may be a multi-dentate amine compound.
In some aspects, the linear and/or branched series of the at least one α-oxocarboxylic acid bonded to an amine compound via ionic bonds may be configured to exclude molecules above, or below a certain molecular weight. Examples of such configurations include but are not limited to the formation of branches that are configured to act as a size exclusion filter.
In one aspect, the amine compound may be a multi-dentate amine compound.
Without intending to be limited to any particular theory, the linear and/or branched series of the at least one α-oxocarboxylic acid bonded to a multi-dentate amine compound via ionic bonds are insoluble, having an increased viscosity, viscoelastic, or gel-like properties. In some aspects, the linear and/or branched series of the at least one α-oxocarboxylic acid bonded to a multi-dentate amine compound via ionic bonds do not contain water.
In some aspects, the increased viscosity, viscoelastic, or gel-like properties of the linear and/or branched series of the at least one α-oxocarboxylic acid bonded to a multi-dentate amine compound via ionic bonds may be configured to enhance, improve, or facilitate adherence of the linear and/or branched series of the at least one α-oxocarboxylic acid bonded to a multi-dentate amine compound via ionic bonds to a solid substrate.
Referring to Example 32, in some aspects, the reduction of POV may be increased by increasing the hydrophobicity of the at least one α-oxocarboxylic acid bonded to a multi-dentate amine compound via ionic bonds.
The POV remedient compounds described herein may be used in combination with known antioxidants. Any antioxidant that has been traditionally used and/or is suitable for a specific application may be combined with the POV remedient compounds of the present invention.
Other antioxidants include but are not limited to synthetic compounds such as BHT (butylated hydroxytoluene), BHA (butylated hydroxy anisole), TBHQ (tertiary butylhydroquinone), propyl gallate, the antioxidants described in U.S. Pat. No. 7,247,658 B2, and the like. Naturally occurring antioxidants can also be used in combination with the POV remedients, including but not limited to tocopherols, tocotrienols, ascorbic acid, carotenoids, flavonoids, anthocyanins, stilbenoids, isoflavones, and catechins.
The present invention is best illustrated but is not limited to the following examples.
50 mL of mixed citrus oils (orange, lemon, lime, mandarin, bergamot, and tangerine) were placed in a 100 round bottom flask at room temperature, along with a stir bar and an argon gas blanket.
A 4:1 v/v isopropanol/pyruvic acid solution was made. 20 mL of this pyruvic acid solution was dripped into the stirred citrus oils at a rate of 0.25 mL/minute via the use of a syringe pump.
When the addition was complete, 10 mL of water and 100 mg of anhydrous sodium carbonate was added to the flask, and the stirring was maintained. When the visible evolution of CO2 had stopped (about 2-4 minutes), the aqueous layer was removed with a pipette and discarded. POV measurements were made on the mixed citrus oil before and after the pyruvic acid treatment.
POV before treatment was 27.261 mEq/L, and the POV after treatment was 4.786 mEq./L. This was about an 82% reduction in POV.
10 mL of autoxidized limonene was placed in a 30 mL glass vial at room temperature, along with a stir bar and an argon gas blanket. 100 μL of 2-oxovaleric acid was added. The vial was shaken once and allowed to stand for 50 minutes. No further treatment was done prior to the POV testing. POV measurements were made on the limonene before and after the 2-oxovaleric acid treatment. POV before treatment was 65.97 mEq./L, and POV after treatment was 17.21 mEq./L. This was an approximately 74% reduction in POV.
20 mL of autoxidized limonene was placed in a 30 mL glass vial at room temperature, along with a stir bar and an argon gas blanket. 250 μL of 2-oxobutyric acid was added. The vial was shaken once and allowed to stand, while being monitored for POV value as a function of time. The data collected is shown in the table below.
The results showed an initial rapid reduction in POV, followed by decline in the rate of POV reduction. This may be due to reagent depletion, but the loss of POV is not sufficient to fully account on a molar basis for all of the added 2-oxobutyric acid. It may be that some hydroperoxides are destroyed very quickly, and other oxidants are destroyed much more slowly. When an additional 500 μL of 2-oxobutyric acid was added, and the sample allowed to stand for an additional 24 hours, the measured POV was 8.577 mEq./L (87.1% total reduction).
20 mL of autoxidized limonene was placed in a 30 mL glass vial at room temperature, along with a stir bar and an argon gas blanket. 200 mg of phenylglyoxylic acid was added, which dissolved. The vial was shaken once and allowed to stand, while being monitored for POV value as a function of time. The data collected is shown in the table below.
20 mL of mixed citrus oil was placed in a 30 mL glass vial at room temperature, along with a stir bar and an argon gas blanket. 400 mg of α-oxo-2-furanacetic acid was added. The vial was shaken once and allowed to stand, while being monitored for POV value as a function of time. The majority of the added α-oxo-2-furanacetic acid did not dissolve, so the limited solubility of the acid will likely act as a controlled release mechanism; as the α-oxo furanacetic acid in solution is consumed by hydroperoxides, more will likely dissolve in accordance will the solubility constant. In this way, the undissolved solid acts as a sink to maintain a steady, low concentration of α-oxo-2-furanacetic acid dissolved in the mixed citrus oil.
In this case, because the time between measurements was relatively long (days instead of minutes), there is the possibility that the untreated mixed citrus oil will oxidize further during the course of the experiment. Therefore, the POV of the treated oil was still compared with the POV of the untreated oil, but the measurement of the untreated oil was re-determined at each time point (rather than just a single, initial value being used). The data collected is shown in the table below.
A skin cream formulation comprising of 0.5 parts cetylstearyl alcohol, 6.0 parts wool wax alcohol, and 93.5 parts white petroleum jelly was created as per the German Pharmacopoeia DAB 2008.
The skin cream was divided into two separate preparations. A highly oxidized limonene sample was added to both preparations, with the first preparation receiving a concentration of oxidized limonene approximately one third of the concentration of the oxidized limonene in the second preparation. Analysis of the oxidized limonene sample showed the sample to contain a mixture of limonene hydroperoxide isomers.
The initial POV of both the first and second skin cream preparations was taken, prior to treatment with 2-oxovaleric acid or phenylglyoxylic acid as follows: 2-oxovaleric acid (second preparation), or phenylglyoxylic acid (first preparation) was thoroughly blended into the skin cream preparations. The POV of the preparations were measured, during addition of the 2-oxovaleric acid. After addition of the 2-oxovaleric acid or phenylglyoxylic acid, the treated preparations were allowed to stand at room temperature. The POV data obtained was corrected for the exact weight of the aliquot of cream titrated at each individual time point and normalized as a percentage to the starting POV.
The second preparation, containing the highest amount of the oxidized limonene sample was treated with approximately 2.3% w/w 2-oxovaleric acid. The results are shown below in
The first preparation, containing the lowest amount of the oxidized limonene sample was treated with approximately 3.9% w/w 2-phenylglyoxylic acid. The results are shown below in
1.461 g (0.01 moles) of α-ketoglutaric acid was dissolved in 10 mL of dry acetone to give a clear solution. This solution was added as one portion to 2.384 g (0.02 moles) of neat NMDEA. The opaque, white emulsion was vortexed vigorously for 3-4 minutes, during which time a second phase had coalesced. The mixture was placed in a freezer for at least 30 minutes, causing the bottom phase to thicken to a waxy solid. While still cold, the top layer was easily removed via decantation or pipet and discarded. Residual acetone was removed from the bottom, product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This resulted in a clear, faint yellow, highly viscous oil at room temperature containing the diammonium salt (AKG-DiNMDEA salt).
A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 19.4% v/v (6 mL oil into 25 mL solvent). Approximately 400 mg (2.0% w/v) of the AKG-DiNMDEA salt was dissolved in 20 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
These data show a reduction in the POV of approximately 94%, 24 hours after addition of the AKG-DiNMDEA salt.
In addition to the treatment done in a model perfume as described above, a similar experiment was done in mixed citrus oil. A sample of mixed citrus oil was made by combining lime, orange, grapefruit, lemon, mandarin, tangerine, and bergamot oils, so that a variety of terpene hydroperoxides would be present in the treated mixture being tested. Approximately 200 mg (1.0% w/v) of the AKG-DiNMDEA salt was added to 20 mL of the mixed citrus oil. The salt did not appear to dissolve completely even after vigorous mixing. Nonetheless, POV measurements were taken as a function of time after the addition. An untreated mixed citrus oil sample was handled similarly to the treated oil and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
This represents only a moderate-to-good improvement in the POV status of the oil; a 59% reduction in POV after over a day of treatment time. This is likely due to the poor solubility of the 2-oxoacid salt in the citrus oil.
1.461 g (0.01 moles) of α-ketoglutaric acid was dissolved in 6 mL of dry acetone. This solution was added dropwise with stirring over the course of 1-2 minutes to a separate solution of 4.268 g (0.02 moles) of N, N dimethyldodecylamine in 6 mL of dry acetone. No visible indication of reaction was seen except that the combined solution warmed up to about 35-40° C. The mixture was shaken briefly but vigorously and cooled in a freezer for 30 minutes. Even when cold, still no precipitation of product occurred, but when the mixture was shaken again, the entire mass almost instantly solidified into a solid, white, waxy substance. This solid was warmed up to 30-35° C. to re-liquify the product so that entrapped acetone could be removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave a white, waxy solid containing the diammonium salt (AKG-DiMeC12A salt).
A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 19.4% v/v (6 mL oil into 25 mL solvent). Approximately 400 mg (2.0% w/v) of the AKG-DiMeC12A salt was dissolved in 20 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
In addition to the treatment done in a model perfume as described above, a similar experiment was done in mixed citrus oil. A sample of mixed citrus oil was made by combining lime, orange, grapefruit, lemon, mandarin, tangerine, and bergamot oils, so that a variety of terpene hydroperoxides would be present in the treated mixture being tested. Approximately 200 mg (1.0% w/v) of the AKG-DiMeC12A salt was dissolved in 20 mL of the mixed citrus oil, and POV measurements were taken as a function of time after the addition. An untreated mixed citrus oil sample was handled similarly to the treated oil and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
These data represent an 89.0% reduction in the POV, within 72 hours (3 days) after the addition of AKG-DiMeC12A. It appears that the AKG-DiMeC12A may have been depleted after the 260 minute time point, because no further reaction happened even after an extended period.
Surface Tension Measurements of Aqueous AKG-DiMeC12A: In order to evaluate the surfactant properties of AKG-DiMeC12A, the reduction in surface tension that it causes in aqueous solution versus pure water was measured. The measurement was made on a Kruss DSA100S Tensiometer by the pendant drop method. A 0.14 weight % solution of AKG-DiMeC12A in water was used for the measurement. This concentration was chosen so the results could be compared to the literature value for known surfactant sodium dodecyl sulfate (SDS) at 5 mM, which is approximately 0.15 weight %. The results show that AKG-DiMeC12A has significant surfactant properties:
Pure water−71.57 mN/m
AKG-DiMeC12A−32.08 mN/m
For comparison, SDS at 5 mM concentration (approximately 0.15 weight %, which is very close to the 0.14 weight % used here) at 273K, has an air-water surface tension in the range of 33.5 to 35.5 mN/m depending on the pH (see Hernainz, F. et al, Colloids Surf. A, 2002, 196, 19-24).
1.461 g (0.01 moles) of α-ketoglutaric acid was dissolved in 10 mL of dry acetone to give a clear solution. This solution was added over the course of 1-2 minutes with stirring to 1.783 g (0.02 moles) of neat 2 dimethylaminoethanol (“Deanol”). The opaque, white emulsion was vortexed vigorously for a minute, during which time a second phase had coalesced. The mixture was placed in a freezer overnight, causing the bottom phase to thicken to extremely viscous, hazy oil. While still cold, the top layer was easily removed via decantation or pipet and discarded. Residual acetone was removed from the bottom product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This produced clear, colorless, viscous oil at room temperature containing the diammonium salt (AKG DiDeanol salt).
A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 19.4% v/v (6 mL oil into 25 mL solvent). Approximately 200 mg (1.0% w/v) of the AKG DiDeanol salt was dissolved in 20 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
2.642 g (0.03 moles) of pyruvic acid was dissolved in 5 mL of dry acetone to give a clear solution. This solution was added dropwise with stirring over the course of 1-2 minutes to a second solution made from 3.575 g (0.03 moles) of NMDEA and 5 mL of dry acetone. The resulting mixture became warm (approximately 35-45° C.) and hazy as the acid solution was added. The milky emulsion was vortexed vigorously for a minute, during which time a second phase had coalesced. The mixture was placed in a freezer for at least 1 hour, causing the bottom phase to increase significantly in viscosity, but not solidify. While still cold, the top layer was easily removed via decantation or pipet and discarded. Residual acetone was removed from the bottom product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave clear, golden colored, highly viscous oil at room temperature containing the diammonium salt (PA-NMDEA salt).
A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of lime, orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 16.7% v/v (40 mL oil into 200 mL solvent, 240 mL total perfume). Approximately 150 mg (1.0% w/v) of the PA-NMDEA salt was dissolved in 15 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
These data suggest that the PA-NMDEA was depleted at the 73.3 hour mark, because the POV of the sample never went any lower after that, even at extended reaction times. This represents >90% reduction in POV; the average untreated oil after 3 days was (6.66+6.58)/2 =6.62 mmol/L, so 0.58/6.62×100=8.76% remaining, or 91.2% reduction in POV).
1.501 g (0.01 moles) of PhGA was dissolved in 5 mL of dry acetone to give a clear solution. This solution was added in one portion to a second solution made from 1.192 g (0.01 moles) of NMDEA and 5 mL of dry acetone. The resulting mixture became warm (approximately 30-35° C.) and turned pale yellow in color, but no haze or precipitate formed. The solution was vortexed vigorously for a minute and placed in a freezer for 30 minutes. Still no precipitate or second layer formed, but the solution was apparently supersaturated. An attempt was made to remove the solvent acetone via a stream of nitrogen, but almost instantly as the nitrogen stream touched the solution, a thick paste of white crystalline material formed. The crystals began to re-dissolve back into the acetone as the mixture warmed to room temperature. The product was re-frozen, causing re-precipitation of the highly crystalline product, and the supernatant acetone was removed while still cold via pipet as much as possible. Residual acetone was then removed under a stream of nitrogen to give pure white, needle shaped crystals. The crystalline product containing the diammonium salt (PhGA-NMDEA salt) was extremely hygroscopic and would liquefy very rapidly if exposed to ambient atmosphere; the white mass of needles had to be kept under vacuum or a rigorous nitrogen blanket to remain crystalline. A weight/yield was not obtained due to the hygroscopicity.
A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of lime, orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 16.7% v/v (40 mL oil into 200 mL solvent, 240 mL total perfume). Approximately 150 mg (1.0% w/v) of the PhGA-NMDEA salt was dissolved in 15 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
These data suggest that while the phenylglyoxylic acid moiety does work to lower the POV in the model perfume, it is less reactive than the non-aryl pyruvates studied. This difference in reactivity may be useful in some circumstances.
25 mL of sunflower oil (from an off-the-shelf, opened 1 quart container with approximately 25% atmospheric headspace; storage time unknown) was placed in a 30 mL vial at room temperature. 250 μL of 2-oxovaleric acid was added. The vial was shaken and allowed to stand at ambient temperature in laboratory lighting on the benchtop. No further treatment was done prior to the POV testing.
POV measurements were made on the sunflower oil before and after the 2-oxovaleric acid treatment. The untreated oil was also re-measured periodically for comparison, since opening of the bottle replenishes atmospheric headspace and can cause the POV of the bottle contents to rise. The % reduction was always calculated versus the most recent POV value on the untreated oil, and if multiple measurements were made, an averaged value (shown in parentheses) was used for the calculation. The results are shown in the table below.
The untreated sunflower oil increased in POV by nearly 40% (12.30/8.81 mmol/L x 100=139.6%) from merely sitting at room temperature in the bottle for 15 days, with a headspace that had been replenished with ambient atmosphere during the brief opening required to do each sampling.
Conversely, the treatment of sunflower oil with 0.83% v/v of 2-oxovaleric acid resulted in an 82.9% reduction in POV after 15 days versus the untreated oil.
3.707 g (0.02 moles) of phenylpyruvic acid was dissolved in 10 mL of dry acetone to give a clear solution. A separate solution was made from 3.283 g (0.02 moles) of N,N-dimethyldecylamine in 10 mL of dry acetone. The amine solution was added dropwise with stirring over the course of 2-3 minutes to the phenylpyruvic acid solution; no visible indication of reaction was seen, and no warming was noticeable. The mixture was shaken briefly but vigorously and cooled in a freezer for 30 minutes. A thick network of white, flocculent, fine crystals was formed, and a small amount of acetone was decanted off of the solid mass while still cold and discarded. The majority of the solvent acetone appeared entrapped within the crystalline network and was removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave a slightly off-white, fluffy crystalline solid in quantitative yield.
Reduction of POV in Sunflower Oil According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of phenylpyruvic acid and N, N-dimethyldecylamine (referred to herein as DiMeC10A-PhPA): 15 mL of sunflower oil that had been stored in a plastic bottle at room temperature for 1 year, but never opened during this storage period, was placed into a 30 mL glass vial, and 0.3032 g of DiMeC10A-PhPA was added to it. The majority of the salt dissolved, but some undissolved solid remained. The mixture was allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. The results are shown in the table below.
This phenyl pyruvate salt produced extremely rapid reduction of the sunflower oil POV.
Reduction of POV in a Model Perfume According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of phenylpyruvic acid and N, N-dimethyldecylamine (referred to herein as DiMeC10A-PhPA): A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of lime, orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 16.7% v/v (40 mL oil into 200 mL solvent, 240 mL total perfume). Approximately 164 mg (1.1% w/v) of the PhPA-DiMeC 10A salt was dissolved in 15 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
The results shown above represent a 87.2% reduction in POV relative to untreated material 7 days after addition of PhPA-DiMeC10A.
2.114 g (0.015 moles) of alpha-oxo-2-furanacetic acid was dissolved in 10 mL of dry acetone. The alpha-oxo-2-furanacetic acid was used as received from the supplier (a greyish-tan colored crystalline solid), and gave a dark brown solution containing a small quantity of undissolved flocculent material. It was decided to proceed with the “as is” material for preliminary screening, and a purified starting material could be made at a later time if the screening results so indicated.
A separate solution was made from 2.780 g (0.015 moles) of N,N-dimethyldecylamine in 10 mL of dry acetone. The amine solution was added dropwise with stirring over the course of 5 minutes to the crude alpha-oxo-2-furanacetic acid solution; no visible indication of reaction was seen, and no warming was noticeable. The mixture was shaken briefly but vigorously and cooled in a freezer for 30 minutes. Even when cold, still no precipitation of product occurred, so the acetone was removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave brown, viscous oil in quantitative yield that crystallized to a tan solid after standing at freezer temperature for several days.
Reduction of POV in Sunflower Oil According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of alpha-oxo-2-furanacetic acid and N, N-dimethyldecylamine (referred to herein as FAA-DiMeC10A): 15 mL of sunflower oil that had been stored in a plastic bottle at room temperature for 1 year, but never opened during this storage period, was placed into a 30 mL glass vial, and 0.3358 g of FAA-DiMeC10A was added to it. The majority of the salt dissolved, but a small amount of dark brown insoluble droplets remained. The mixture was allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. The results are shown in the table below.
Reduction of POV in a Model Perfume According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of alpha-oxo-2-furanacetic acid and N, N-dimethyldecylamine (referred to herein as FAA-DiMeC10A): A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of lime, orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 16.7% v/v (40 mL oil into 200 mL solvent, 240 mL total perfume). Approximately 150 mg (1.0% w/v) of the FAA-DiMeC10A salt was dissolved in 15 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
The results shown above represent a 40.0% reduction in POV relative to untreated material 7 days after addition of FAA-DiMeC 10A. It appears that while the α-oxo-2-furanacetic acid moiety does work to lower the POV in the model perfume, it is less reactive/slower than the non-aryl α-oxocarboxylic acids studied.
2.922 g (0.02 moles) of alpha-ketoglutaric acid was dissolved in 10 mL of dry acetone. A separate solution was made from 12.937 g (0.04 moles) of tris[2-(2-(methoxyethoxy)ethyl]amine (TMEEA) in 5 mL of dry acetone. The amine solution was added dropwise with stirring over the course of 2 minutes to the AKG solution; no visible indication of reaction was seen, but the resulting mixture became slightly warm (approximately 35-45° C.). The mixture was shaken briefly but vigorously and cooled in a freezer for 30 minutes. Even when cold, still no precipitation of product occurred, so the acetone was removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave a clear, golden-brown colored, slightly viscous oil in quantitative yield.
Reduction of POV in Sunflower Oil According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of alpha-ketoglutaric acid and tris[2-(2-(methoxyethoxy)ethyl]amine (referred to herein as AKG-diTMEEA): 15 mL of sunflower oil that had been stored in a plastic bottle at room temperature for 1 year, but never opened during this storage period, was placed into a 30 mL glass vial, and 0.5081 g of AKG-diTMEEA was added to it. The higher than usual weight of this compound was used because of its' very high molecular weight (792.96 g/mole). This salt dissolved totally to give a clear, golden-brown oil. The solution was allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. The results are shown in the table below.
1.461 g (0.01 moles) of alpha-ketoglutaric acid was dissolved in 6 mL of dry acetone. This solution was added dropwise with stirring over the course of 1-2 minutes to a separate solution of 4.268 g (0.02 moles) of N,N-dimethyldodecylamine in 6 mL of dry acetone. No visible indication of reaction was seen except that the combined solution warmed up to about 35-40° C. The mixture was shaken briefly but vigorously and cooled in a freezer for 30 minutes. Even when cold, still no precipitation of product occurred, but when the mixture was shaken again, the entire mass almost instantly solidified into a solid, white, waxy substance. This solid was warmed up to 30-35° C. to re-liquefy the product so that entrapped acetone could be removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave a white, waxy solid in quantitative yield.
Reduction of POV in Sunflower Oil According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of alpha-ketoglutaric acid and N,N-dimethyldodecylamine (referred to herein as AKG-DiMeC12A): 15 mL of sunflower oil that had been stored in a plastic bottle at room temperature for 1 year, but never opened during this storage period, was placed into a 30 mL glass vial, and 0.3062 g of AKG-DiMeC12A was added to it. This salt did not dissolve totally, but gave a hazy, gel-like suspension with the sunflower oil. The mixture was allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. The results are shown in the table below.
2.642 g (0.03 moles) of pyruvic acid was dissolved in 5 mL of dry acetone to give a clear solution. This solution was added dropwise with stirring over the course of 1-2 minutes to a second solution made from 3.575 g (0.03 moles) of NMDEA and 5 mL of dry acetone. The resulting mixture became warm (approximately 35-45° C.) and hazy as the acid solution was added. The milky emulsion was vortexed vigorously for a minute, during which time a second phase had coalesced. The mixture was placed in a freezer for at least 1 hour, causing the bottom phase to increase significantly in viscosity, but not solidify. While still cold, the top layer was easily removed via decantation or pipet, and discarded. Residual acetone was removed from the bottom product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave clear, golden colored, highly viscous oil at room temperature in quantitative yield.
Reduction of POV in Sunflower Oil According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of pyruvic acic acid and N-methyl diethanolamine (referred to herein as PA-NMDEA): 15 mL of sunflower oil that had been stored in a plastic bottle at room temperature for 1 year, but never opened during this storage period, was placed into a 30 mL glass vial, and 0.2988 g of PA-NMDEA was added to it. This salt appeared to dissolve and/or disperse, but the resulting mixture was not totally clear; it had a translucent, colloidal appearance. The mixture was allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. The results are shown in the table below.
α-ketoglutaric acid is a strong acid, wherein a solution of 0.114 g of α-ketoglutaric acid in 10 mL of water had a measured pH of 1.75. Consequently, the amount of the α-ketoglutaric acid in solution in a hydroalcoholic perfume base may have to be limited, to prevent alterations of the organoleptic properties on the perfume raw materials.
A model perfume was made using 90/10 v/v ethanol/water as a solvent, to which, a mixture of orange, grapefruit, and bergamot oils was added. The mixed citrus oil was loaded into the solvent at approximately 19.4% v/v (6 mL oil into 25 mL solvent). Approximately 240 mg (1.2% w/v) of α-ketoglutaric acid was dissolved in 20 mL of the mixed citrus perfume, and a POV measurement was taken the following day. The results are shown in the table below.
These data show a complete reduction in the POV of the formulated perfume 24 hours after treatment of the formulated perfume with α-ketoglutaric acid.
Oxaloacetic acid is known to be unstable in aqueous solutions (see H. A. Krebs, Biochemistry (1942) 36, 303-305), leading to evolution of carbon dioxide and pyruvic acid. Nonetheless, oxaloacetic acid is effective in reducing the POV in solutions that will solubilize it (for example, hydroalcoholic perfumes). However, it is unclear whether the POV reduction occurs via oxaloacetic acid directly, or via liberated pyruvic acid, or both. An analysis of the reaction products (acetic acid versus malonic acid) could distinguish the two pathways, but this was not pursued here.
A model perfume was made using 90/10 v/v ethanol/water as a solvent, to which, a mixture of orange, grapefruit, and bergamot oils was added. The mixed citrus oil was loaded into the solvent at approximately 19.4% v/v (6 mL oil into 25 mL solvent). Approximately 166 mg (0.83% w/v) of oxaloacetic acid was dissolved in 20 mL of the mixed citrus perfume, and POV measurements were taken at the times indicated in the table below.
These data show a complete reduction in the POV of the formulated perfume 24 hours after treatment of the formulated perfume with oxaloacetic acid.
3.003 g (0.02 moles) of phenylglyoxylic acid was dissolved in 10 mL of dry acetone to give a clear solution. A separate solution was made from 2.603 g (0.02 moles) of 1-(2-hydroxyethyl)-2-imidazolidinone in 10 mL of dry acetone. Since 1-(2-hydroxyethyl)-2-imidazolidinone was supplied as a 75% w/w solution in water, the actual amount of the 75% reagent used was 3.471 g to compensate for the weight of solvent water. The 1-(2-hydroxyethyl)-2-imidazolidinone amine solution was added dropwise with stirring over the course of 3 minutes to the phenylglyoxylic acid solution; no visible indication of reaction was seen, and no warming was noticeable. The mixture was shaken briefly but vigorously and cooled in a freezer for 30 minutes. Even when cold, still no precipitation of product occurred, so the acetone solvent was removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave clear, pale yellow, highly viscous oil in quantitative yield.
Reduction of POV in Model Perfume According to One Aspect Presented Herein Using the Ammonium Salt formed via the Reaction of phenylglyoxylic acid and 1 (2 hydroxyethyl)-2-imidazolidinone (referred to herein as PhGA-HEI): A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of lime, orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was added into the solvent at approximately 16.7% v/v (40 mL oil into 200 mL solvent, 240 mL total perfume). Approximately 150 mg (1.0% w/v) of the PhGA-HEI salt was dissolved in 15 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
The results shown above represents a 58.8% reduction in POV relative to untreated material 7 days after addition of PhGA-HEI. It appears that while the phenylglyoxylic acid moiety does work to lower the POV in the model perfume, it is less reactive/slower than the non-aryl α-oxocarboxylic acids studied. This difference in reactivity may be useful in some circumstances.
2.922 g (0.02 moles) of alpha-ketoglutaric acid (AKG) was dissolved in 10 mL of dry acetone to give a clear solution. A separate solution was made from 5.206 g (0.04 moles) of 1-(2-hydroxyethyl)-2-imidazolidinone (HEI) in 10 mL of dry acetone. Since HEI was supplied as a 75% w/w solution in water, the actual amount of the 75% reagent used was 6.942 g to compensate for the weight of solvent water. The HEI amine solution was added dropwise with stirring over the course of 3 minutes to the AKG solution; no visible indication of reaction was seen, and no warming was noticeable. The mixture was shaken briefly but vigorously and cooled in a freezer for 1 hour. Even when cold, still no precipitation of product occurred, so the acetone solvent was removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave clear, water-white, extremely viscous oil in quantitative yield.
Reduction of POV in Model Perfume According to One Aspect Presented Herein Using the Diammonium Salt formed via the Reaction of α-ketoglutaric acid and 1 (2 hydroxyethyl)-2-imidazolidinone (referred to herein as AKG-HEI): A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of lime, orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 16.7% v/v (40 mL oil into 200 mL solvent, 240 mL total perfume). Approximately 150 mg (1.0% w/v) of the AKG-HEI salt was dissolved in 15 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
The results shown above represent a 92.1% reduction in POV relative to untreated material 7 days after addition of AKG-DiHEI.
2.922 g (0.02 moles) of α-ketoglutaric acid was dissolved in 12 mL of dry acetone. This solution was added dropwise with stirring over the course of 1-2 minutes to a separate solution of 4.268 g (0.02 moles) of N, N-dimethyldodecylamine in 6 mL of dry acetone. The mixture was shaken, but no visible indication of reaction was seen except that the combined solution warmed up to about 35-40° C. The mixture remained clear for a few minutes, but when shaken again, the entire mass instantly solidified into a solid white crystalline block. This solid was warmed up to 30-35° C. to re-liquify the product so that entrapped acetone could be removed via a stream of nitrogen followed by treatment in a vacuum oven at room temperature. This gave a white, waxy solid in quantitative yield.
A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 19.4% v/v (6 mL oil into 25 mL solvent). Approximately 200 mg (1.0% w/v) of the AKG-monoMeC12A salt was dissolved in 20 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
These data represent represents total and complete reduction in the POV, within 26 hours after the addition of AKG-mono(DiMeC12A).
In addition to the treatment done in a model perfume as described above, a similar experiment was done in mixed citrus oil. A sample of mixed citrus oil was made by combining lime, orange, grapefruit, lemon, mandarin, tangerine, and bergamot oils, so that a variety of terpene hydroperoxides would be present in the treated mixture being tested. Approximately 200 mg (1.0% w/v) of the AKG-mono(DiMeC12A) salt was added into 20 mL of the mixed citrus oil, but a substantial portion of it did not dissolve. POV measurements were taken as a function of time after the addition. An untreated mixed citrus oil sample was handled similarly to the treated oil and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
These data represent a 94.2% reduction in POV relative to untreated material 28.0 hours after addition of the AKG-mono(DiMeC12A) salt.
Surface Tension Measurements of Aqueous AKG-monoDiMeC12A: In order to evaluate the surfactant properties of AKG-Mono(DiMeC12A), the reduction in surface tension that it causes in aqueous solution versus pure water was measured. The measurement was made on a Kruss DSA100S Tensiometer by the pendant drop method. A 0.14 weight % solution of AKG-Mono(DiMeC12A) in water was used for the measurement. This concentration was chosen so the results could be compared to the literature value for known surfactant sodium dodecyl sulfate (SDS) at 5 mM, which is approximately 0.15 weight %. The results show that AKG-Mono(DiMeC12A) has significant surfactant properties:
Pure water−71.57 mN/m
AKG-monoDiMeC12A−32.93 mN/m
For comparison, SDS at 5 mM concentration (-0.15 weight %, which is very close to the 0.14 weight % used here) at 273K, has an air-water surface tension in the range of 33.5 to 35.5 mN/m depending on the pH (see Hernainz, F. et al, Colloids Surf. A, 2002, 196, 19-24).
0.61 g (0.003 moles) of I-3-PA-NMDEA was placed in 4 mL of methanol, but it only partially dissolved. A separate mixture was made of 0.357 g (0.003 moles) of NMDEA in 2 mL of acetone, which formed a clear solution. The amine solution was added in one portion to the indole-3-pyruvic acid and vortexed vigorously for 1 minute. There was some solid that remained undissolved, so the mixture was placed in a 40° C. water bath. As it warmed, all the material dissolved to form a dark orange, clear solution. The mixture was allowed to cool to room temperature, but no precipitate formed. The solution was placed in a freezer for 30 minutes, during which time light pink needle-like crystals had fallen out. The mother liquor was removed with a pipet; it was shown to contain a substantial amount of lower purity material that could be further recovered by blowing down the solvent under a stream of nitrogen to give a deep orange solid. For the purpose of preliminary experiments, the two portions of product were recombined pending the development of a more efficient crystallization procedure. The yield was quantitative.
A model perfume was made using 90/10 v/v ethanol/water as a solvent, and a mixture of orange, grapefruit, and bergamot oils as the perfume oil. The mixed citrus oil was loaded into the solvent at approximately 19.4% v/v (6 mL oil into 25 mL solvent). Approximately 244 mg (1.2% w/v) of the I-3-PA-NMDEA salt was dissolved in 20 mL of the mixed citrus perfume, and POV measurements were taken as a function of time after the addition. An untreated perfume sample was handled similarly to the treated perfume and also tested, because the POV can rise rapidly with handling of the sample (opening the bottle, agitation, etc.). The results are shown in the table below.
These data represent a rapid reduction in POV relative to untreated material 60 minutes after addition of the I-3-PA-NMDEA salt.
It had been observed that a reduction of POV in citrus oils could be produced even with α-oxocarboxylic acid salts that were practically insoluble in the citrus oil being treated. It appeared that this observation held true for both solid salts and liquid salts (which tend to be of high viscosity), although the rate and efficiency of the reduction was not as high as that for soluble salts. It was hypothesized that the surface area of contact between the α-oxocarboxylic acid salt phase and the citrus oil phase was likely a limiting factor, so if true, any method of increasing the contact area should promote a more rapid, facile reaction.
Towards that goal, an attempt was made to spread a thin, highly disperse layer of the diammonium salt formed from α-ketoglutaric acid and two equivalents of N-methyldiethanolamine (AKG-DiNMDEA) onto a chemically inert, high surface area solid support. In this example, a commercially available household scrubbing pad made of extremely thin stainless steel (a Scotch-Brite Scrubby® pad made by 3M Company) was used.
Preparation of an AKG-DiNMDEA coated pad: A single pad was cleaned as follows: The pad was placed in a 250 mL glass beaker and covered completely with pentane. The beaker was sonicated for three minutes, the pentane drained, and the procedure repeated with acetone. The acetone was also drained, and the pad dried in a vacuum oven at room temperature for one hour. The pad weighed 19.229 g both before and after the cleaning procedure, so no discernable weight loss was observed as a result of the cleaning.
A solution was made from 3.0 g of AKG-DiNMDEA and 10 mL of fragrance grade ethanol. The pad was loaded by spreading the solution over the stainless steel pad via pipet, and drying the ethanol off under vacuum at room temperature. This was best accomplished with the solution split into about three portions, with a drying step in between each; there was some run-off when attempted in one portion, because the pad could not completely hold that much solution. When all the ethanol was removed, the viscous AKG-DiNMDEA appeared to cling to the pad tightly enough so that the pad could be transferred between containers without loss of the liquid coating.
Treatment of mixed citrus oil: A sample of mixed citrus oil was made by combining lime, orange, grapefruit, and bergamot oils, so that a variety of terpene hydroperoxides would be present in the treated mixture being tested. Into two separate 250 mL glass bottles, 150 mL each of the mixed citrus oil was placed. This allowed for a significant atmospheric headspace to be present in the closed bottles, which would be replenished by fresh atmosphere/oxygen upon every opening of the bottle to withdraw an aliquot for testing. This arrangement was designed to mimic the oxygen exposure resulting from typical handling in production of a drum of citrus oil raw material and should lead to realistic levels of autoxidation in the contained oils.
The AKG-DiNMDEA coated pad was placed in one of the bottles (the Treated Sample) and totally submerged under the mixed citrus oil therein. In the second bottle, nothing besides the mixed citrus oil was placed (the Untreated Sample). These bottles were allowed to stand on the laboratory bench under ambient temperature and lighting conditions throughout the testing period. Periodically, an aliquot was withdrawn from each bottle for POV testing. Downward flow of the coating off of the pad, as evidenced by the appearance of a puddle of AKG-DiNMDEA collecting at the bottom of the vessel, took several weeks to occur to a noticeable extent. The interphase contact area presumably became lower as this flow progressed, likely reducing the efficiency of the reduction reaction. Nonetheless, significant protection of the treated citrus oil from autoxidation-induced POV increase occurred, as reported in the Table below and in
Recharge of the pad: After 26 days, it was observed that the POV of the Treated Sample began to increase slightly (see
The pad was removed from the mixed citrus oil and washed in succession with 100 mL each of acetone, then 95% ethanol, then acetone again. The cleaned pad was dried under vacuum at room temperature and reloaded with AKG-DiNMDEA. A simpler procedure was tried this time to recharge/reactivate/reload the Scrubby®. Instead of applying a solution and evaporating the solvent, the viscous AKG-DiNMDEA oil was simply rubbed into the steel coils; approximately 3.2 g of AKG-DiNMDEA was placed onto the surface of the steel pad and kneaded in with gloved hands to distribute the oil as evenly as possible. Then the recharged Scrubby® was placed back into the container of treated citrus oil, and POV monitoring was continued as before. The timepoint corresponding to the recharge is shown by a vertical purple line in
This Example reports the treatment of exemplary consumer product formulations. The consumer product formulations had a measurable level of oxidation as received, as shown in the table below, but the POV levels were low except the all-purpose cleaner. All of the samples had not been fragranced, so the POV was be associated with autooxidized base components. The five consumer product formulations were spiked with an extremely oxidized limonene that was produced in a photoreactor as a source of mixed limonene hydroperoxide isomers (the POV was 1434 mmol/L). The oxidized limonene was spiked into each at a level of 10 μL per gram, so approximately 14.3 mmol/L of POV would be added to the existing, as-received POV.
In all cases, the treatment with an α-oxocarboxylic acid ammonium salt produced a rapid and extensive lowering of the sample's POV; the hydroperoxides present in the sample were consumed/destroyed via a defined, controlled reaction with the α-oxocarboxylic acid to yield harmless and predictable by-products. In some cases, the untreated sample showed a much slower but steady reduction in POV; this is likely due to the limonene hydroperoxides reacting with and oxidizing base components, to form unknown by-products. This may have deleterious effects on the formulation in many cases, such as malodor formation, discoloration, changes in physical properties, etc. Such uncontrolled, undirected lowering of POV will likely lower the skin sensitizing potential of a sample due to consumption of sensitizing hydroperoxides, but is not necessarily positive to the formulation in all aspects. POV of Consumer Product Samples As Received (before spike with oxidized limonene)
Sample Preparation: 40 mL (Sample #3) or 40 g (Samples #1, 2, 4 & 5) were each spiked with 0.4 mL of oxidized limonene and mixed until homogeneous. Half of each spiked consumer product sample was transferred to a second container and treated as described in the table below with 0.5-1% (w/w) of a 2-oxocarboxylic acid ammonium salt, then mixed to homogeneity. Each of the five pairs of two samples, treated & un-treated, were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. The results are described below.
Sample 1, Hand Dishwashing Liquid Soap (HDLS)— See
Sample 2, Shampoo—See
Sample 3, All Purpose Cleaner (APC)— See
Sample 4, Skin Cream—See
Sample 5, Antiperspirant Stick (APS)— See
In this Example, a series of non-citrus-derived essential oils were treated as described below with AKG-DiTMEEA (the diammonium salt made from alpha-ketoglutaric acid (AKG, CAS #328-50-7) and Tris[2-(2-(methoxyethoxy)ethyl]amine (TMEEA, CAS #70384-51-9) in a 1:2 molar ratio). The results indicate that the claimed treatment is effective over a broad range of essential oils, which contain a broad range of terpenes and other small organic molecules such as aromatics. Therefore, a very broad range of organic hydroperoxides will be present as autoxidation products in these other oil types, and they all appear to be reduced by 2-oxoacids (specifically an α-ketoglutarate ammonium salt in this case).
The data below shows nine oils along with the POV obtained on each as received from production stock. For each oil, 20 mL was placed in separate 30 mL glass vials, and subjected to the following procedure for 8 days on a daily basis; the vial was opened to refresh the atmospheric headspace, then reclosed and shaken to maximize the gas/liquid contact, then stored on the benchtop under ambient laboratory temperature and lighting conditions. This procedure was designed to mimic the typical handling of a container in a production setting, in which the oil gets consumed in many small aliquots, rather than an entire container at a time.
On Day 4, each oil sample was split in half, so two 10 mL aliquots were placed in separate vials to create a “Treated” and an “Untreated” sample. To the Treated sample of each oil type, AKG-DiTMEEA was added as per the Dosing chart below. The pine oil had an extremely high POV, so the dosing and measurement protocol was somewhat different from the other oils. The daily opening, shaking, and standing procedure continued for another four days until the POV measurements were taken. It can be seen that 8 days of such handling of the untreated oils caused significant increases in POV measurement.
The Siberian Pine Oil, even as received, had a POV that was unusually high, to such a degree that stoichiometric depletion of the AKG-DiTMEEA is likely to occur. For this reason, two levels of AKG-DiTMEEA treatment were tried, x2 and x4 the treatment used on the other oils. The results indicate that even greater amounts may be necessary to completely remediate this Pine Oil sample, because AKG-DiTMEEA has a high molecular weight due to the large amine groups, and there is a low stoichiometric ability to scavenge hydroperoxides per unit weight. A different, lower molecular weight 2-oxoacid salt may be a better choice.
POV of Untreated Oils, Before and After Handling:
Dosing/Treatment of Non-Citrus Essential Oils with AKG-DiTMEEA
AKG-DiTMEEA Treatment (4 Days) of Non-Citrus Essential Oils
In this Example, the following amines were used to make salts of α-ketoglutaric acid:
The following general procedure was used to prepare seven substituted ammonium salts of alpha-ketoglutaric acid (“AKG”): AKG (approximately 0.01 mole, approximately 1.461 g) was dissolved in 10 mL of dry acetone to give a clear solution. This solution was added in one portion to the solution of mixed amines in 5 mL of acetone; a total of 0.02 moles of basic N atoms were supplied by each amine mixture. This fully neutralized the two carboxylic acid moieties present in the 0.01 mole of AKG. The resulting opaque, white emulsion was vortexed vigorously for 2-3 minutes, during which time a second phase coalesced and separated from the milky mixture. The mixture was placed in a freezer overnight, causing the bottom phase to thicken to a waxy solid. While still cold, the top layer was removed via decantation and discarded. Residual acetone was removed from the bottom product layer via a stream of nitrogen, followed by treatment in a vacuum oven at room temperature for at least 2 hours. In each case, this produced highly viscous, colorless or yellow oil at room temperature. This procedure was repeated to make 7 different AKG cross-linked disalts as shown below:
Mixed citrus oil was prepared as follows for use in the testing of the AKG salts: Approximately equal portions of cold-pressed orange, lemon, lime, bergamot, and grapefruit oils were combined into a mixed oil. These citrus oils had been handled extensively for other purposes in the laboratory for several months and were becoming autoxidized to varying degrees, but each had a significant POV value. The combined oil as used at the start of the experiment had a POV value equal to approximately 18 millimole/liter, but handling during the experimental procedure caused the POV of the untreated oils to increase. The treated oils were subjected to identical handling (during sampling at each time point, the vial was opened and the headspace was refreshed from ambient atmosphere). The percentage of POV reduction at each time point was calculated in relation to the POV of untreated oil at that time, not the initial POV value.
The Preparation of Samples for Testing/Treatment: To a series of vials, each charged with approximately 0.2 g of one of the seven AKG ionically crosslinked disalts (#1-#7 as prepared above) was added 5 mL of mixed citrus oil. Each mixture was vortexed for 1-2 min, and then allowed to stand on the benchtop under ambient laboratory light and temperature conditions. The process was repeated for each salt, wherein seven samples were prepared in total. POV measurements were taken as a function of time after the addition. Untreated citrus oil (also 5 mL) was handled similarly to the treated oil and also tested, because the POV can rise rapidly with handling of the sample. Preparations #1 through #7 were practically insoluble and all formed a second phase in the mixed citrus oil.
The seven treated and one untreated citrus oil samples had POV measurements taken periodically over 3 4 days. The results are shown below and in
#1. AKG-NMDEA(90%)+THED(10%) [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N-methyl diethanolamine (90%, NMDEA, CAS #105-59-9) and N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine (10%, THED, CAS #140 07 8) in a 1:1.8: 0.1 molar ratio] was used to reduce the POV of a mixed citrus oil. POV measurements were taken over four days. The results are shown in the table below, and in
#2. AKG-NMDEA(80%)+THED(20%) [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N-methyl diethanolamine (80%, NMDEA, CAS #105-59-9) and N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine (20%, THED, CAS #140 07-8) in a 1:1.6: 0.2 molar ratio] was used to reduce the POV of a mixed citrus oil. POV measurements were taken over four days. The results are shown in the table below, and in
#3. AKG-NMDEA(80%)+THED(10%)+BDMPP(10%) [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N-methyl diethanolamine (80%, NMDEA, CAS #105-59-9), N,N,N′,N-tetrakis(2-hydroxyethyl)ethylenediamine (10%, THED, CAS #140-07-8) and 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol (10%, BDMPP, CAS #67151-63-7) in a 1: 1.6: 0.1: 0.067 molar ratio] was used to reduce the POV of a mixed citrus oil. POV measurements were taken over four days. The results are shown in the table below, and in
#4. AKG-NMDEA(60%)+THED(20%)+BDMPP(20%) [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N-methyl diethanolamine (60%, NMDEA, CAS #105-59-9), N,N,N′,N-tetrakis(2-hydroxyethyl)ethylenediamine (20%, THED, CAS #140-07-8) and 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol (20%, BDMPP, CAS #67151-63-7) in a 1:1.2:0.2:0.134 molar ratio] was used to reduce the POV of a mixed citrus oil. POV measurements were taken over three days. The results are shown in the table below, and in
#5. AKG-THED [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N,N,N′,N-tetrakis(2-hydroxyethyl)ethylenediamine (20%, THED, CAS#140 07-8) in a 1:1 molar ratio] was used to reduce the POV of a mixed citrus oil. POV measurements were taken over three days. The results are shown in the table below, and in
#6. AKG-THED(80%)+BDMPP(20%) [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylene diamine (80%, THED, CAS #140-07-8) and 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol (20%, BDMPP, CAS #67151-63-7) in a 1:0.8:0.13 molar ratio] was used to reduce the POV of a mixed citrus oil. POV measurements were taken over four days. The results are shown in the table below, and in
#7. AKG-BDMPP [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328 50-7) with 1-[bis [3-(dimethylamino)propyl]amino]-2-propanol (BDMPP, CAS #67151 63-7) in a 1:0.67 molar ratio] was used to reduce the POV of a mixed citrus oil. POV measurements were taken over four days. The results are shown in the table below, and in
Citric acid is a tridentate carboxylic acid, capable of forming three ionic bonds with amine compounds. Without intending to be limited to any particular theory, citric acid allows branching to occur in ionic bonding networks formed in these preparations, with the expectation that branching may increase viscosity. The preparations were tested in mixed citrus oil raw material, and in hydroalcoholic model perfumes made from mixed citrus oils. The prepared AKG salts were insoluble in the pure citrus oil raw materials, but worked nonetheless as shown below. They were completely soluble in the hydroalcoholic model perfume, and they worked more rapidly when dissolved.
Preparation of citrus model perfumes: 180 mL of ethanol (flavor grade), 20 mL of distilled water, and 40 mL of mixed citrus oil were combined and vortexed. The resulting oil load was 40 mL oil/240 mL total=16.67% v/v, giving a slightly hazy, yellow solution.
The list of amines and acids used to make the AKG salt preparations was as follows:
The following general procedure was used to prepare four citric acid containing, ionically crosslinked substituted ammonium salts of AKG: AKG (approximately 0.009 mole, approximately 1.314 g) and citric acid (0.001 mole X 2/3=0.000667 mole, 0.128g) was dissolved in 10 mL of dry acetone by vigorous vortexing. This solution was added in one portion to the solution of mixed amines in 5 mL of acetone; a total of 0.02 moles of basic N atoms were supplied by each amine mixture. This fully neutralized the carboxylic acid moieties present in the 0.009 moles of AKG and 0.000667 moles of citric acid (CA). The resulting opaque, white emulsion was vortexed vigorously for 2-3 minutes, during which time a second phase coalesced and separated from the milky mixture. The mixture was placed in a freezer overnight, causing the bottom phase to thicken to a waxy solid. While still cold, the top layer was removed via decantation and discarded. Residual acetone was removed from the bottom product layer via a stream of nitrogen, followed by treatment in a vacuum oven at room temperature for at least 4 hours. In each case, this produced highly viscous, colorless or yellow oil at room temperature. This procedure was repeated to make four different AKG/CA cross-linked di salts as shown in the table below:
The Preparation of Samples for Testing/Treatment: The model citrus perfume (15 mL each, in four separate 16 mL vials) was treated with one of the four AKG-CA salts (-0.2 g each, see the table below). All AKG-CA salts were dissolved in the model citrus perfume, resulting in a yellow solution with little haze and no color change, appearing indistinguishable from the untreated sample. These solutions, treated & un-treated, were allowed to stand on the bench top in ambient laboratory light at room temperature, and POV measurements were taken periodically. For all treated samples, no color change occurred during the entire study period. The results are shown in the table below, and in
A. AKG-CA+NMDEA [The cross linked diammonium salt made from alpha-ketoglutaric acid (90%, AKG, CAS #328-50-7) & citric acid (10%, CA, CAS #77-92-9) with N-methyldiethanol amine (NMDEA, CAS #105-59-9) in a 9:0.67:20 molar ratio] was used to reduce the POV of a mixed citrus model perfume. POV measurements were taken over five days. The results are shown in the table below, and in
B. AKG-CA-THED [The cross linked diammonium salt made from alpha-ketoglutaric acid (90%, AKG, CAS #328-50-7) & citric acid (10%, CA, CAS #77-92-9) with N,N,N′,N′-tetrakis(2-hydroxy ethyl)ethylene diamine (THED, CAS #140-07-8) in a 9:0.67:10 molar ratio] was used to reduce the POV of mixed citrus model perfume. POV measurements were taken over five days. The results are shown in the table below, and in
C: AKG-CA-THED(80%)+BDMPP(20%): [The cross linked diammonium salt made from alpha-ketoglutaric acid (90%, AKG, CAS #328-50-7) & citric acid (10%, CA, CAS#77-92-9) with N,N,N′,N′-tetrakis(2-hydroxyethyl) ethylene diamine (80%, THED, CAS#140-07-8) and 1 [bis[3-(dimethylamino)propyl]amino]-2-propanol (20%, BDMPP, CAS#67151-63-7) in a 9:0.67:8:1.3 molar ratio] was used to reduce the POV of mixed citrus model perfume. POV measurements were taken over five days. The results are shown in the table below, and in
D. AKG-CA+BDMPP [The cross linked diammonium salt made from alpha-ketoglutaric acid (90%, AKG, CAS #328-50-7) & citric acid (10%, CA, CAS #77-92-9) with 1-[bis[3-(dimethyl amino)propyl]amino]-2-propanol (BDMPP, CAS #67151-63-7) in a 9:0.67:6.7 molar ratio] was used to reduce the POV of mixed citrus model perfume. POV measurements were taken over four days. The results are shown in the table below, and in
The compounds used were prepared as described in Examples 27 and 28 above. A significant difference in these two experiments is that the AKG-Citric Acid salts all dissolved in the hydroalcoholic model perfume, but they were insoluble in the mixed citrus oil itself.
Treatment of mixed citrus oil: To each of two vials charged with approximately 0.2 g of AKG di-salt (C: AKG(90%)-CA(10%)-THED(80%)+BDMPP(20%), or D: AKG(90%)-CA(10%)+BDMPP) was added 5 mL of mixed citrus oil. The vials were vortexed for 2 minutes and allowed to stand on the bench top under ambient laboratory light and temperature conditions. Periodic POV measurements were taken as a function of time after the addition. The results are shown in the tables below and in
C: AKG(90%)-CA(10%)+THED(80%)-BDMPP(20%): [The cross linked diammonium salt made from alpha-ketoglutaric acid (90%, AKG, CAS #328-50-7) & citric acid (10%, CA, CAS #77-92-9) with N,N,N′,N′-tetrakis(2-hydroxyethyl) ethylene diamine (80%, THED, CAS #140-07-8) and 1 [bis[3-(dimethylamino)propyl]amino]-2-propanol (20%, BDMPP, CAS #67151-63-7) in a 9:0.67:8:1.3 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
D. AKG(90%)-CA(10%)+BDMPP [The cross linked diammonium salt made from alpha-ketoglutaric acid (90%, AKG, CAS #328-50-7) & citric acid (10%, CA, CAS #77 9) with 1 [bis[3-(dimethyl amino)propyl]amino]-2-propanol (BDMPP, CAS #67151-63-7) in a 9:0.67:6.7 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
Acids and/or Multidentate/Polymeric Amines/Bases.
Without intending to be limited to any particular theory, the concept of forming a network of ionic bond linkages that would increase the viscosity of the 2-oxoacid salt containing material, or create gel-type rheological behavior in the 2 oxoacid salt phase, can be extended beyond bidentate or tridentate acids or bases. For example, if a polymeric acid such as polyacrylic acid, or a polymeric amine such as chitosan, is used as a component, the ionic network that is formed can be complex and extensive. Such an extensive network is likely to create a bulk physical property in the material that is extremely viscous, or gel like, or in some cases even solid/granular. As shown below, the materials so produced did indeed display these physical properties, but nonetheless were shown to retain their ability to react with terpene hydroperoxides contained in a distinct, separate phase composed of mixed citrus oil.
AKG amine salts prepared with a polyacrylic acid component:
Procedure to prepare the salts: Four vials were separately charged with AKG (0.0099 or 0.0095 mole, 1.446 or 1.388 g) and polyacrylic acid (0.0002 or 0.001 mole, 0.0144 or 0.072 g) as per the table above, and dry acetone was added to each (10 mL for #1 & 3, 14-15 mL for #2 & 4; the extra acetone was necessary to dissolve the PAA). The vials were vortexed for 30 seconds each. A very small amount of white solid, which appeared to be an impurity from the AKG, was not dissolved completely and settled to the bottom of the vial, so the top clear solution was added as one portion to the amines in 5 mL acetone (0.02 moles of total N groups, THED: 2.363 g or BDMPP: 1.636 g, see the table above). The opaque, white emulsion was vortexed vigorously for 2 minutes, during which time a second phase coalesced. The mixture was placed in a freezer over the weekend, causing the bottom phase to thicken to a waxy solid. While still cold, the top layer was removed via decantation and discarded. Residual acetone was removed from the bottom, product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature for 7 days.
#1P and #4P were used for a POV reduction test in mixed citrus oil, as shown below.
Treatment of the mixed citrus oil: To a vial charged with approximately 0.2 g of AKG-PAA salt preparation (as listed above) was added 5 mL of mixed citrus oil. The mixture was vortexed for 2 min, and then allowed to stand on the benchtop under ambient laboratory light and temperature conditions. Periodically, POV measurements were taken as a function of time after the addition. None of the AKG-PAA salt preparations dissolved in the oil. The results are shown in the tables below and in
#1P: AKG(99%)-PAA1(%)+THED: [The cross linked diammonium salt made from alpha-ketoglutaric acid (99%, AKG, CAS #328-50-7) & polyacrylic acid (1%, PAA, CAS #: 9003-01-4) with N,N,N′,N′-tetrakis(2-hydroxyethyl) ethylene diamine (THED, CAS #140-07-8) in a 9.9:0.2:10 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
#4P: AKG(95%)-PAA(5%)+BDMPP [The cross linked diammonium salt made from alpha-ketoglutaric acid (95%, AKG, CAS #328-50-7) & polyacrylic acid (5%, PAA, CAS #: 9003-01-4) with 1-[bis[3-(dimethyl amino)propyl]amino]-2-propanol (BDMPP, CAS#67151-63-7) in a 9.5:1:6.7 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
General procedure to prepare AKG-PAA-PEI ammonium salts: Four vials were separately charged with AKG (0.0095 or 0.01 mole, 1.388 g or 1.484 g) and poly(acrylic acid) (0.001 mole, 0.072 g) as per the table above (the actual mass used is shown in the table), and 14 mL of dry acetone was added to each. The vials were vortexed for 30 seconds each. A very small amount of white solid, which appeared to be an impurity from the AKG, was not dissolved completely and settled to the bottom of the vial, so the top clear solution was added as one portion to the amine mixtures (0.02 moles of total N groups, see the table below) dissolved in 10 mL acetone. The opaque, white emulsion was vortexed vigorously for 2 minutes, during which time a second phase coalesced. The mixture was placed in a freezer over the weekend, causing the bottom phase to thicken to a waxy solid. While still cold, the top layer was removed via decantation and discarded. Residual acetone was removed from the bottom product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature for 7 days.
Treatment of the mixed citrus oil: To a vial charged with approximately 0.2 g of AKG-PAA-PEI salt preparation (as listed above) was added 5 mL of mixed citrus oil. The mixture was vortexed for 2 min, and then allowed to stand on the benchtop under ambient laboratory light and temperature conditions. Periodically, POV measurements were taken. The results are shown in the tables below and in
APP1: AKG(95%)-PAA(5%)+THED(95%)-PEI(5%): [The cross linked diammonium salt made from alpha-ketoglutaric acid (95%, AKG, CAS #328-50-7) & polyacrylic acid (5%, PAA, CAS #9003-01-4) with N,N,N′,N′-tetrakis(2-hydroxyethyl) ethylene diamine (95%, THED, CAS #140 07-8) & polyethylenimine (5%, PEI, CAS #: 9002-98-6) in a 9.5:1:9.5:1 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
APP2: AKG(95%)-PAA(5%)+BDMPP(95%)-PEI(5%): [The cross linked diammonium salt made from alpha-ketoglutaric acid (95%, AKG, CAS #328-50-7) & polyacrylic acid (5%, PAA, CAS #9003-01-4) with 1-[bis[3-(dimethyl amino)propyl]amino]-2-propanol (BDMPP, CAS #67151 63-7) & polyethylenimine (5%, PEI, CAS #: 9002-98-6) in a 9.5:1:6.3:1 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
APPS: AKG(95%)-PAA(5%)+PEI: [The cross linked diammonium salt made from alpha-ketoglutaric acid (95%, AKG, CAS #328-50-7) & polyacrylic acid (5%, PAA, CAS #: 9003-01-4) with polyethylenimine (PEI, CAS #: 9002-98-6) in a 9.5:1:20 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
APP4: AKG+PEI: [The cross linked diammonium salt made from alpha-ketoglutaric acid (95%, AKG, CAS #328-50-7) with polyethylenimene (PEI, CAS #: 9002-98-6) in a 1:2 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over 12 days. The results are shown in the table below, and in
Because of the highly ionic nature of the 2-oxoacid ammonium salt phases made from a ketoglutaric acid and amines such as NMDEA, THED, and BDMPP, it is likely that terpene hydroperoxides will not partition into these phases to a large extent. This may be expected to slow down the reduction of the hydroperoxides to the corresponding alcohols, and make the POV remediation happen more slowly.
If the 2-oxoacid phase can be made more hydrophobic, the partitioning of terpene hydroperoxides into may increase, and the higher concentration may result in a faster reduction. However, if the character of the 2-oxoacid phase gets too hydrophobic, it will dissolve in the material being treated, such as citrus oil, and will no longer be maintained as a second phase. Fine tuning of the hydrophobic nature of the 2-oxoacid phase may allow for more efficient POV remediation while still maintaining the remedient material as a separate, distinct second phase.
To accomplish this, it may be possible to replace a portion of the active 2 oxoacid with a bidentate, tridentate, or multidentate acid that has greater hydrophobicity than the 2 oxoacid. We used sebacic acid for this purpose; it contains two carboxylic acid moieties linked together by a straight eight carbon chain. This unfunctionalized eight carbon section infers upon sebacic acid a greater hydrophobic character than AKG, and by varying the percentage of sebacic acid in the mixture it should be possible to adjust the overall hydrophobicity of the 2 oxoacid salt phase.
In addition, we used the bidentate amine THPED, which has more hydrophobic character than THED; THPED (aka; Neutrol TE® by BASF) has four additional methyl groups relative to THED. These four methyl groups also confer a greater hydrophobic nature onto the amine component.
Procedure to prepare the salts: To each vial that was charged with AKG and sebacic acid (“SA”) was added dry acetone (approximately 13 mL for AST-1 & 2 and 25 mL for AST-3, because SA has relatively lower solubility in acetone than AKG). The mixtures were vortexed. A very small amount of white solid, which appeared to be an impurity in the AKG, was not dissolved completely and was precipitated at the bottom of the vial. The top clear solution was added as one portion to the amine solution (0.01 moles in 5 mL acetone). The opaque, white emulsion was vortexed vigorously for approximately 1 min, during which time a second phase coalesced. The mixture was placed in a freezer overnight, causing the bottom phase to thicken to a waxy solid. While still cold, the top layer was removed via decantation and discarded. Residual acetone was removed from the bottom product layer via a stream of nitrogen followed by treatment in a vacuum oven at room temperature for approximately 10 days.
Treatment of the mixed citrus oil: To a vial charged with approximately 0.2 g of AKG di-salt (AST1-AST 3 as listed above) was added 5 mL of mixed citrus oil. The mixture was vortexed for 1 min and allowed to stand on the benchtop under ambient laboratory light and temperature. POV measurements were taken as a function of time after the addition. The salt was not dissolved in the oil but precipitated as a mobile liquid at the bottom of the vial. The results are shown in the tables below and in
AST-1: AKG(95%)-SA(5%)+THPED: [The cross linked diammonium salt made from alpha-ketoglutaric acid (95%, AKG, CAS #328-50-7) & sebacic acid (5%, SA, CAS #: 111-20-6) with N,N,N′,N′-Tetrakis(2-Hydroxy-propyl)ethylenediamine (THPED, CAS #102-60-3) in a 9.5:0.5:10 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over six days. The results are shown in the table below, and in
AST-2: AKG(90%)-SA(10%)+THPED: [The cross linked diammonium salt made from alpha-ketoglutaric acid (90%, AKG, CAS #328-50-7) & sebacic acid (10%, SA, CAS #: 111-20-6) with N,N,N′,N′-Tetrakis(2-Hydroxy-propyl)ethylenediamine (THPED, CAS #102-60-3) in a 9:1:10 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over six days. The results are shown in the table below, and in
AST-3: AKG(80%)-SA(20%)+THPED: [The cross linked diammonium salt made from alpha-ketoglutaric acid (80%, AKG, CAS #328-50-7) & sebacic acid (20%, SA, CAS #: 111-20-6) with N,N,N′,N′-Tetrakis(2-Hydroxy-propyl)ethylenediamine (THPED, CAS #102-60-3) in a 8:2:10 molar ratio] was used to reduce the POV of mixed citrus oil. POV measurements were taken over six days. The results are shown in the table below, and in
A comparison of the results from #5 AKG-THED or #6 AKG-THED(80%)+BDMPP(20%) above, with each of the three materials that contain sebacic acid/THPED, shows that the more hydrophobic active salt phases did indeed provide faster hydroperoxide reduction/POV remediation. This was especially true at the earliest time points in the experiments, with the difference on average being most pronounced at the shortest time point of approximately 0.1 days. The difference caused by the sebacic acid is less pronounced, as expected, when compared to #7 AKG-BDMPP (BDMPP is more hydrophobic than THED, so the benefit of the sebacic acid/THPED should be less). This data shows that the inclusion of hydrophobic components into the active salt phase can make the hydroperoxide reduction faster and in some cases more complete. The hydrophobic component does not necessarily need to be a multidentate compound with all acid groups or all amine/basic groups; it could have a mixture of acid and basic moieties, such as an amino acid or a derivative thereof, for example N,N-dimethyl phenylalanine, or a hydrophobic protein.
Rheological simple shear flow measurements were conducted on several of the reported 2 oxoacid samples using an Anton Paar Modular Compact Rheometer MCR 302 using the Parallel Plate geometry (25 mm). All samples were analyzed at 25° C.±0.2° C. Viscosity η curves were generated using a shear rate (y) sweep ranging from 0.001 to 10 1/s. The results are shown in
We measured the moisture content before and after a sequence of rheology measurements using Karl Fischer Titration. The 2-oxoacid was loaded onto the rheometer stage, the parallel plate was lowered to a measuring distance of 1 mm, the sample was trimmed to remove any excess sample not in contact with the stage and plate, and the experiment was started. Multiple analyses were performed on each sample. The sample was measured 5 times consecutively without lifting the parallel plate. After these 5 measurements the parallel plate was lifted and the sample was exposed to the ambient air, humidity, and temperature in the laboratory for 15 minute intervals up to 90 minutes. After each 15 minute interval, the sample was re-analyzed using the same rheological method. The viscosities of all samples decreased as the sample picked up increasing amounts of moisture over the 90 minute exposure time. At the end of 90 minutes the sample was collected into a plastic cuvette, capped, and sealed with parafilm (to keep out any further moisture pickup) for future Karl Fischer titration analysis. The Karl Fischer titration table below notes the moisture content before and after rheological measurements. It is clear that these materials are extremely hygroscopic, and dry samples must be used to obtain meaningful comparative viscosity measurements. The results are shown in the table below.
It is evident that all of these samples exhibit Newtonian behavior in the shear rate range studied. The small variations in viscosity are minor and could be caused by the small amount of crystals in the sample. It is clear that the different formulations aimed to increase viscosity were successful, demonstrating a significant increase (e.g. 2 orders of magnitude) in viscosity at all shear rates studied.
In this aspect, it is not necessary to use a bidentate 2-oxoacid such as α-ketoglutaric acid, because the gel or molecular association is not formed via the 2-oxoacid component being incorporated into an ionic network. Monodentate 2-oxoacids (those that contain only one acidic moiety in the molecule) such as pyruvic acid or 2-oxovaleric acid, can work as well since they only need to be soluble in the aqueous gel formed from water and whatever gelling/thickening agent is used. It should even be possible to use 2-oxoacids that are water insoluble but could form an emulsion of active droplets that are encased in the rigid aqueous gel.
In this case, a gel is formed from materials that are inactive toward the POV remediation, but just serve the purpose of creating a semi-solid aqueous phase into which a 2 oxoacid component can be dissolved, emulsified, or suspended. Any material that forms a gel within an aqueous phase is potentially usable; gelatin, various gums such as xanthan gum, alginates, agars, synthetic polymers such as polyacrylic acids (Carbomers®), etc. can all be the gel forming component.
Two examples are shown below; one based on gelatin and one based on xanthan gum.
Porcine Skin Gelatin with AKG-NMDEA salt [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N-methyl diethanolamine (NMDEA, CAS#105-59-9): Approximately 500 mg of gelatin from porcine skin, type A, gel strength 300 (Prod. #G2500 from Sigma-Aldrich Chemical Co.) was added to 20 mL of distilled water, and the mixture was warmed until a clear solution was produced. When the solution of gelatin had cooled to 48° C., two mL was placed in a 15 mL vial, and 105 mg of AKG-NMDEA salt was dissolved in it. The solution was placed in a refrigerator to set the gel at the bottom of the vial. Next, 10 mL of mixed citrus oil was added to the vial, forming a second phase of mobile liquid above the solidified, aqueous gelatin layer. A blank vial was also made from 10 mL of the mixed citrus oil. Both the treated and blank vials were stored on the laboratory benchtop for seven days, when POV measurements were taken. The results are as follows, showing a 39.6% reduction in POV:
Blank−31.67 mmol/L
Xanthan Gum with AKG-NMDEA salt [The diammonium salt made from a ketoglutaric acid (AKG, CAS #328-50-7) with N-methyl diethanolamine (NMDEA, CAS#105-59-9): Approximately 700 mg of xanthan gum was added to 20 mL of distilled water, and the mixture was stirred with a spatula until a uniform, thick gel was produced. Two mL of the gel was placed in a 15 mL vial, and 110 mg of AKG-NMDEA salt was stirred into it until dissolved. Next, 10 mL of mixed citrus oil was added to the vial, forming a second phase of mobile liquid above the thick, aqueous gel layer. A blank vial was also made from 10 mL of the mixed citrus oil. Both the treated and blank vials were stored on the laboratory benchtop for seven days, when POV measurements were taken. The results are as follows, showing a 45.8% reduction in POV:
Blank−31.67 mmol/L
Treated−17.17 mmol/L
In this example, the ability of α-ketoglutaric acid salt to replace the conventional antioxidant butylhydroxytoluene (BHT) as a stabilizing agent for fine fragrances was investigated.
BHT was used as a control and was compared to the α-ketoglutaric acid salt. BHT and the α-ketoglutaric acid salt was added to perfume oil at three different concentrations (0.05, 0.10 and 0.25%), and mixed with magnetic stirrer within 30 minutes.
Next, eau de toilette (“EDT”) formulations containing the test and control formulations were prepared as follows: 10% (wt) of perfume oil concentrate, 10% (wt) of deionised water, 80% (wt). The final concentrations of BHT or α-ketoglutaric acid salt were 0.005%, 0.010% and 0.025% in EDT.
The resulting EDT formulations were stored at 45° C. for 2 months. After storage, samples of the EDT formulations were taken and analyzed by gas chromatography, to determine the concentration of acetaldehyde diethyl acetal. The amount of acetaldehyde diethyl acetal is directly linked to the general oxidation of the EDT as it is formed by oxidation of ethanol, according to the reaction described below:
The results are shown in the table below.
The EDT formulation lacking BHT or α-ketoglutaric acid salt contained 150 ppm of acetaldehyde diethyl acetal and its odor was observed to have been modified by the oxidation during the stability test. The odor was typical of an oxidized perfume.
The EDT formulation containing BHT (from 0.005% to 0.025% in EDT) was less oxidized and the amount of Acetaldehyde diethyl acetal was 85 ppm with 0.025% BHT in EDT.
The EDT formulation containing α-ketoglutaric acid salt was further stabilized, in that the concentration of Acetaldehyde diethyl acetal was 10 ppm with 0.025% in EDT and 33 ppm of Acetaldehyde diethyl acetal with 0.010% of in EDT.
Blank Samples: In all of the experiments below, an Untreated Oil (Blank) sample was maintained. The Blank was always packaged, stored, handled, and sampled in exactly the same manner as the Treated Sample, excepting the addition of the 2-oxoacid salt. In this way, the effect of the atmospheric oxygen in the headspace volume would be similar. For example, the ratio of the headspace volume to the volume of oil, and the area of contact between the headspace and the oil surface, would be the same for Treated and Untreated samples.
Sensory Evaluations: Phenylpyruvic acid and pyruvic acid and their salts each have an aroma themselves that is somewhat acidic in character. Conversely, α-ketoglutaric acid or its salts have no such aroma. The flavorists that conducted the sensory evaluations herein noted that this acidic aroma was somewhat confounding to the evaluation of rancidity in the oils, more so when the rancidity was not very severe. The effect was that the rancidity of oils containing phenylpyruvic or pyruvic salts were probably overestimated, especially early in the study before the flavorists gained through experience the ability to more clearly differentiate the oxoacid aroma from rancidity. No such overestimation occurred with the odorless α-ketoglutaric acid salts. This overestimation phenomenon was probably operational in some of the examples where the sensory rankings did not correlate well with the HPLC aldehyde data. The sensory-HPLC data correlation is much stronger with the α-ketoglutarate examples.
Low Oleic Sunflower Oil: Treatment of Low Oleic Sunflower Oil with PhPA-DiMeC10A [the ammonium salt made from phenylpyruvic acid and N,N-dimethyldecylamine in a 1:1 molar ratio]:
Into a 30 mL glass vial was placed 15 mL of low oleic sunflower oil, which had been freshly purchased from a local supermarket, opened 44 days before, and kept at room temperature. To this vial, 0.3001 g of PhPA-DiMeC 10A was added. The majority of the salt dissolved, but some undissolved solid remained. The mixture was allowed to stand on the bench top in ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, rancid-smelling aldehydes by HPLC with DNPH derivatization (see method below), and sensory evaluation. The results are as follows:
POV data:
The data shows that the treatment was extremely rapid and effective, but at some time between the 35 day time point and the 76 day time point, the PhPA-DiMeC10A appears to have become depleted. When the depletion occurred, the treated sample began to autoxidize as well as the untreated sample; still, the improvement is dramatic.
HPLC data:
Sample Preparation (Dinitro phenylhydrazine[DNPH]derivatization): DNPH derivatives of aldehyde/ketone products in oxidized oils and treated oxidized oils were synthesized as follows:
Approximately 0.500 g of the triglyceride was diluted to 12 mL by addition of propan-2-ol (IPA). 1 mL of this diluted oil mixture was added to 1 mL of diluted DNPH solution, which was prepared separately by mixing DNPH (3 g/L in IPA) and 3% aqueous HCL and diluted to 12 mL with propan-2-ol (IPA). The reaction vial was stirred and kept at 40° C. for 1 hr to accelerate the derivatization reaction. Then the reaction mixture was cooled to room temperature, neutralized with 20% trimethylamine in IPA, and centrifuged at 5000 rpm for 5 min. The supernatant was then injected for HPLC analysis as follows:
HPLC Analysis Method: An Agilent 1100 series HPLC system equipped with a diode array detector was used.
Column: Phenomenex Luna C18 (2) column (250×4.6 min, Sum).
Column Temperature: 30° C.
Flow Rate: 0.8 mL/min
Injection Volume: 5 μL
Detection: UV absorbance at 250, 300, 366 and 385 nm
Mobile Phase Gradient:
HPLC Results—Untreated (Blank)
HPLC Results—Treated with PhPA-DiMeC10A
Sensory data: Sensory evaluation guidelines
Sensory Evaluation Results:
Treatment of Low Oleic Sunflower Oil with PA-NMDEA [the ammonium salt made from pyruvic acid and N-methyl diethanolamine in a 1:1 molar ratio]:
Into a 30 mL glass vial was placed 10 mL of low oleic sunflower oil, which had been freshly purchased at a local supermarket, opened 50 days before, and kept at room temperature. To this vial 0.2002 g of PA-NMDEA was added. The majority of the salt dissolved. The mixture was allowed to stand on the bench top under ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data: Sample Preparation (DNPH derivatization): As described above.
HPLC results—Untreated (Blank):
HPLC Results—Treated with PA-NMDEA
Sensory data: Sensory evaluation guidelines: As described above
Treatment of Low Oleic Sunflower Oil with AKG-DiMeC12A [the ammonium salt made from alpha-ketoglutaric acid and N,N-dimethyldodecylamine in a 1:2 molar ratio]
Into a 30 mL glass vial was placed 10 mL of low oleic sunflower oil, which had been freshly purchased at a local supermarket, opened 50 days before, and kept at room temperature. To this vial, 0.2400 g of AKG-DiMeC12A was added. The salt did not dissolve totally, but gave a hazy, gel like suspension. The mixture was allowed to stand on the bench top under ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
85%
The data shows that the treatment was rapid and effective, but at some time between the 29 day time point and the 76 day time point, the AKG-DiMeC12A appears to have become depleted. When the depletion occurred, the treated sample began to autoxidize as well as the untreated sample; still, the improvement was dramatic.
HPLC data: Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with AKG-DiMeC12A:
Sensory data: Sensory evaluation guidelines: As described above
High Oleic Sunflower Oil:
Treatment of High Oleic Sunflower Oil with PhPA-DiMeC10A [the ammonium salt made from phenylpyruvic acid and N,N-dimethyldecylamine in a 1:1 molar ratio]:
Into a 30 mL glass vial was placed 15 mL of high oleic sunflower oil that had been stored in a plastic bottle at room temperature, but never opened. To this vial, 0.301 g of PhPA-DiMeC 10A was added. The majority of the salt dissolved, but some undissolved solid remained. The mixture was allowed to stand on the bench top under ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with PhPA-DiMeC10A:
Sensory data: Sensory evaluation guidelines: As described above
Treatment of High Oleic Sunflower Oil with PA-NMDEA [the ammonium salt made from pyruvic acid and N-methyl diethanolamine in a 1:1 molar ratio]:
Into a 30 mL glass vial was placed 15 mL of high oleic sunflower oil that had been stored in a plastic bottle at room temperature, but never opened. To this vial 0.3002 g of PA-NMDEA was added. The majority of the salt dissolved. The mixture was allowed to stand on the bench top under ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, of rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
55%
42%
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC results—Treated with PA-NMDEA:
Sensory data: Sensory evaluation guidelines: As described above
Treatment of High Oleic Sunflower Oil with AKG-DiMeC12A [the ammonium salt made from alpha-ketoglutaric acid and N,N-dimethyldodecylamine in a 1:2 molar ratio]
Into a 30 mL glass vial was placed 15 mL of high oleic sunflower oil that had been stored in a plastic bottle at room temperature, but never opened. To this vial 0.302 g of AKG-DiMeC12A was added. The salt did not dissolve totally, but gave a hazy, gel like suspension. The mixture was allowed to stand on the bench top under ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, of rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with AKG-DiMeC12A:
Sensory Data:
Sensory evaluation guidelines: As described above
Soybean Oil:
Treatment of Soybean Oil with PhPA-DiMeC10A [the ammonium salt made from phenylpyruvic acid and N,N-dimethyldecylamine in a 1:1 molar ratio]:
Into a 30 mL glass vial was placed 15 mL of soybean oil that had been stored in a plastic bottle at room temperature, but never opened. To this vial, 0.301 g of PhPA-DiMeC 10A was added. The majority of the salt dissolved, but some undissolved solid remained. The mixture was allowed to stand on the bench top in ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with PhPA-DiMeC10A:
Sensory data: Sensory evaluation guidelines: As described above
Treatment of Soybean Oil with PA-NMDEA [the ammonium salt made from pyruvic acid and N-methyl diethanolamine in a 1:1 molar ratio]:
Into a 30 mL glass vial was placed 15 mL of soybean oil that had been stored in a plastic bottle at room temperature, but never opened. To this vial 0.3002 g of PA-NMDEA was added. The majority of the salt dissolved. The mixture was allowed to stand on the bench top in ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, of rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data: Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with PA-NMDEA:
Sensory data: Sensory evaluation guidelines: As described above
Treatment of Soybean Oil with AKG-DiMeC12A [the ammonium salt made from alpha-ketoglutaric acid and N,N-dimethyldodecylamine in a 1:2 molar ratio]
Into a 30 mL glass vial was placed 15 mL of soybean oil that had been stored in a plastic bottle at room temperature, but never opened. To this vial 0.302 g of AKG-DiMeC12A was added. The salt did not dissolve totally, but gave a hazy, gel like suspension. The mixture was allowed to stand on the bench top in ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, of rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with AKG-DiMeC12A:
Sensory data: Sensory evaluation guidelines: As described above
Extra Virgin Olive Oil: Treatment of Extra Virgin Olive Oil with PhPA-DiMeC10A [the ammonium salt made from phenylpyruvic acid and N,N-dimethyldecylamine in a 1:1 molar ratio]:
Into a 30 mL glass vial was placed 15 mL of extra virgin olive oil that had been stored in a brown glass bottle at room temperature, but never opened. To this vial 0.301 g of PhPA-DiMeC10A was added. The majority of the salt dissolved, but some undissolved solid remained. The mixture was allowed to stand on the bench top in ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, of rancid-smelling aldehydes by HPLC with DNPH derivatization (see the method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with PhPA-DiMeC10A:
Sensory data: Sensory evaluation guidelines: As described above
Treatment of Extra Virgin Olive Oil with AKG-DiMeC12A [the ammonium salt made from alpha-ketoglutaric acid and N,N-dimethyldodecylamine in a 1:2 molar ratio]
Into a 30 mL glass vial was placed 15 mL of extra virgin olive oil that had been stored in a brown glass bottle at room temperature, but never opened. To this vial 0.302 g of AKG-DiMeC12A was added. The salt did not dissolve totally, but gave a hazy, gel like suspension. The mixture was allowed to stand on the bench top in ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, of rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data:
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with AKG-DiMeC12A:
Sensory data: Sensory evaluation guidelines: As described above
Treatment of a Formulated Ranch Salad Dressing: Treatment of Salad Dressing with PhPA-DiMeC10A [the ammonium salt made from phenylpyruvic acid and N,N-dimethyldecylamine in a 1:1 molar ratio]:
Into 30 mL glass vial was placed 15 g of a commercial salad dressing that had been stored in the lab at room temperature for an unknown but extended period after opening. To this vial, 0.4002 g of PhPA-DiMeC 10A was added and mixed well. The mixture was allowed to stand on the bench top under ambient laboratory light at room temperature. Periodically, measurements were recorded of the POV by titration, rancid-smelling aldehydes by HPLC with DNPH derivatization (see method above), and sensory evaluation. The results are shown below:
POV data
HPLC data:
Sample Preparation (DNPH derivatization): As described above.
HPLC Results—Untreated (Blank):
HPLC Results—Treated with PhPA-DiMeC10A:
Sensory data: Sensory evaluation guidelines: As described above
The extent of rancidity in the soap formulation tested was determined by measuring the content of aldehyde and ketone reaction products of the soap oils present. DNPH derivatives of aldehydes/ketone products in soap and treated soap were synthesized as follows:
0.1000 g of a soap formulation, either treated or untreated with DiMeC10A-PhPA were separately measured and diluted to 12 mL by the addition of propan-2-ol. 1 mL of this prepared diluted mixture was added to 1 mL of diluted DNPH solution which was prepared separately by mixing DNPH (3 g/L) and 3% HCL and diluted into 12 mL by the addition of propan-2-ol. The reaction vial was stirred and kept at 40C for 1 hr to accelerate derivatization reaction. Then it was cooled to room temperature and neutralized with 20% triethylamine and centrifuged at 5000 rpm for 5 min. The sample was then injected into the HPLC column. The results are shown in the table below:
These data suggest that the treatment of a soap formulation with DiMeC10A-PhPA reduced the amount of aldehyde and ketone reaction products of the soap oils, and therefore remediates, or reduces rancidity. The sensory properties of the treated and untreated soap formulation is shown below.
Without intending to be limited to any particular theory, reduced sulfur compounds such as thiols may readily react with hydroperoxides, resulting in their reduction, most likely to the corresponding alcohol. Many low molecular weight thiols such as ethane thiol, are extremely malodorous and therefore may be unsuitable for use in a fragranced product or food product. However, certain thiol compounds are not malodorous and could be used in a satisfactory manner Such compounds include amino acid and/or peptide derived thiols such as cysteine derivatives (for example, cysteine ethyl ester hydrochloride, N-acetylcysteine methyl ester, and glutathione).
Treatment of a Model Perfume: A model mixed citrus perfume (15 mL in each of three 16 mL vials) was treated with the sulfur containing compounds (approximately 0.15 g for each, see list below). The vials were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. Some brownish discoloration was noted for the L-Cysteine ethyl ester hydrochloride treated sample. The results are shown in the table below. The POV of the Untreated Model Perfume was 5.55 mmol/L.
Without intending to be limited to any particular theory, Ascorbic acid and its' esters, such as ascorbyl palmitate, are widely used antioxidants in many applications. However, in fine fragrances, home and skin care products, and other cosmetics, it has a tendency to cause discoloration problems. Phosphorylated versions of ascorbic acid are used in skincare products to provide the cosmeceutical benefits of vitamin C topical application without the discoloration problems. Herein we use phosphorylated ascorbic acid analogues to lower the POV of mixed citrus oil and a model citrus perfume.
Treatment of a Model Perfume: The model citrus perfume (15 mL for each, in a 16 mL vial, YIWA-1702, pg61) was treated with the ascorbic acid salt (approximately 0.15 g for each, see list below) and measured via POV titration. All ascorbic acid salt was dissolved in the model citrus perfume, resulted in a yellow solution with little haze, the same as the un-treated. These solutions, treated & un-treated were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. For all treated samples, no color changing happened during the entire studying period.
Treatment of a Combined Citrus Oil: Mixed citrus oil (9 mL each into separate vials) was treated with the phosphorylated ascorbic acid salts (approximately 0.35 g for each) listed above. The treated & un-treated oils were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. For all treated samples, no color change was observed during the entire experimental period.
The results are shown in the tables below and in
Citrus oil treated with Vc-PTNa (0.357 g):
Citrus perfume treated with Vc-PTNa (0.1611 g)
Citrus oil treated with Vc-PSeMg (0.3585 g)
Citrus perfume treated with Vc-PSeMg (0.1544 g)
Treatment of a Model Perfume: The model citrus perfume (15 mL in each of four 16 mL vials) was treated with test compounds (approximately 0.3 g for each, only PMDSiH was miscible with the perfume; the other three were not). The treated & un-treated perfumes were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. For all treated samples, no color change was observed during the testing period.
Treatment of a Combined Citrus Oil: Mixed citrus oil (6 mL in each of four separate 9 mL vials) was treated with the test compounds (approximately 0.2 g for each; all were miscible with the citrus oil). The treated & un-treated oils were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. For all treated samples, no color change was observed during the treatment period.
Test Compounds
For mixed citrus oil, 5 mL+ approximately 200 mg Si compound was used, approximately 40 mg/mL. For model citrus perfume, 15 mL+ approximately 300 mg Si compound was used, approximately 20 mg/mL
The results are shown in the tables below and in
Citrus oil treated with DMESi (0.2614 g)
Citrus oil treated with PMDSi (0.2511 g)
Citrus oil treated with PMHSi-a (0.2525 g)
Citrus oil treated with PMHSi-b (0.2482 g)
Citrus perfume treated with DMESi (0.3247 g)
Citrus perfume treated with PMDSi (0 0.3302 g)
Citrus perfume treated with PMHSi-a (0.3185 g)
Citrus perfume treated with PMHSi-b (0.3123 g)
Treatment of a Model Perfume: The model citrus perfume (15 mL in each of four 16 mL vials) was treated with test compounds The treated & un-treated perfumes were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. For all treated samples, no color change was observed during the testing period. The results are shown in the table below. The starting POV of the Untreated Model Perfume was 5.55 mmol/L.
Treatment of a Combined Citrus Oil: Mixed citrus oil (6 mL in each of two 8 mL vials) was treated with oxalic acid monoesters (approximately 0.12 g). The treated & un-treated oils were allowed to stand on the benchtop under ambient laboratory light at room temperature, and POV measurements were taken periodically. Both compounds dissolved in the mixed citrus oil. Instead of a 1 mL sample size as usual, 0.5 mL oil was used for each titration due to the very high POV of the untreated oil. The results are shown in the table below and in
Oxalic acid monoesters:
Citrus oil treated with monobutyl oxalate (0.1243 g):
Citrus Oil Treated with Monobenzyl Oxalate (0.1234 g):
Without intending to be limited to any particular theory, 1,4-dihydropyridines are known to act as reducing agents in biological systems (for example, NADH; the reduced form of Nicotinamide Adenine Dinucleotide). This example demonstrates that this heterocyclic ring system non-enzymatically prevents an increase in the POV of autoxidizing limonene.
HDPA: N(3),N(3),N(5),N(5),2,6-Hexamethyl-1,4-Dihydro-3,5-Pyridinedicarboxamide (HDPA, C13H21N3O2, MW=251.331)
Preparation of the Treated Sample: Oxidized limonene (100 μL, with a starting POV of approximately 38 mmol/L) was treated with 2 mg of HDPA (approximately 2 eq of HP). The treated & un-treated limonene samples were allowed to stand on the benchtop under ambient laboratory light at room temperature, and HPLC Chemiluminescence measurements were taken periodically. The same quantity of untreated limonene was prepared in a 2nd vial and monitored similarly to the treated one for comparison. The results are shown in the table below, and in
This experiment shows the use of hydrolysable esters of 2-oxoacids and/or oxalic acids to cause POV lowering via hydrolysis of an ester moiety to produce a controlled and/or extended in-situ release of a 2-oxoacid, oxalic acid monoester, or oxalic acid itself. 2-oxoacids and oxalic acids are very strong acids that can damage aroma and/or formulation components if they are added all at once in high concentration without buffering; controlled release prevents such damage.
The 2-oxoacid ester or oxalate ester acts as a non-acidic source of the parent 2-oxoacid, oxalic acid monoester, or oxalic acid itself. The ester releases the 2-oxoacid, oxalic acid monoester, or oxalic acid at a controlled rate via hydrolysis caused by water in the treated material. Some water in the treated material is essential for this reason. The liberated 2-oxoacid, oxalic acid monoester, or oxalic acid reacts with harmful hydroperoxides that are present in the treated material usually as a result of autoxidation and consumes them chemically via an oxidative decarboxylation reaction. The hydroperoxides end up as the structurally corresponding alcohols, which are relatively harmless.
The following compounds were tested as described below:
360 mL EtOH (flavor grade or HPLC grade)+40 mL DI water+80 mL mixed citrus oil. Concentration: 80 mL/480 mL=16.67% v/v. This resulted in a yellow solution with slight haziness.
Treatment of citrus perfume (10 mg/mL):
The model citrus perfume (40 mL aliquots, each in separate 40 mL vials) was treated with compounds 1 6 (-0.4 g each) by simply mixing in and dissolving the treating compound. The treated & untreated solutions were allowed to stand on the benchtop in ambient laboratory light at room temperature, and POV measurements were taken periodically. The samples were also monitored for color changes during the entire study period.
For AKG-diEtO (compound 7), a separate experiment was done: The model citrus perfume (22 mL, in a 36 mL vial) was treated with AKG-diEtO (-0.23 g) and monitored as per the above procedure for POV measurement.
POV versus Time plots are shown for Di-n-Butyl α-Ketoglutarate (
% POV Reduction versus Time plots are shown for Di-n-Butyl α-Ketoglutarate (
A POV-lowering compound is mixed into a consumer product formulation as an ingredient. In a body care application such as a skin moisturizing cream or antiperspirant, the consumer product may be placed on the user's skin and left on for an extended time period, frequently one day or more. Other body care applications, such as shampoo or soap, may be quickly rinsed off, but the brief and transient exposure is repeated on a regular and ongoing basis.
Three examples are shown below representing a variety of widely-used consumer body care products (Samples 1, 2, and 3). The products are representative of a formulation type that is typical and currently popular in the marketplace. The user would simply use the body care product in the usual manner.
Sample Preparation: 40 g each of Samples 1, 2, and 3 were spiked with the specified amount (see the table below) of a specified 2-oxoacid salt and mixed until homogeneous to make the treated samples. A second 40 g each of Samples 1, 2, & 3 were kept “as is” without spiking with the 2-oxoacid salts, to make untreated samples. Each of the three pairs of treated and un-treated samples, will be used by elderly[what is elderly? [other populations, eg, dialysis patients?′ people, on either the left (untreated) or right side (treated) of their body in their normal daily routines. Their body odor on each side will be evaluated comparatively at various time periods after product application. Examples are shown below:
Consumer Product 2-Oxocarboxylic Acid Ammonium Salt Used for Treatment
(dosage and identification)
#1. Shampoo 1.0% (w/w) of PA-NMDEA: pyruvic acid+N-methyl diethanolamine, 1:1 molar ratio
#2. Skin Cream 0.2% (w/w) of AKG-DiMeC12A: α-ketoglutaric acid+
N,N dimethyldodecylamine, 1:2 molar ratio
#3. Anti-Perspirant
Stick 0.5% (w/w) of AKG-diTMEEA: α-ketoglutaric acid+Tris[2 (2 (methoxyethoxy)ethyl]amine, 1:2 molar ratio
The use of these bodycare products reduces the amount of 2-nonenal formed by oxidation of skin lipids, and thereby reduces the characteristic odor called “old person smell”.
It is expected that POV remediating agents will be effective at lowering the level of 2-nonenal and other aldehydes formed by lipid oxidation, thereby lowering the level of unpleasant smelling compounds in the subject's body odor.
Publications cited throughout this document are hereby incorporated by reference in their entirety. Although the various aspects of the invention have been illustrated above by reference to examples and preferred embodiments, it will be appreciated that the scope of the invention is defined not by the foregoing description but by the following claims properly construed under principles of patent law.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20207895.2 | Nov 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/065531 | 6/9/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63037224 | Jun 2020 | US |
