Patent Application
20170196237
The present document relates to the field of directionally-freeze cast, lyophilized, and impregnated candies and foods.
Ingredients
The prime constituents of milk chocolate or dark chocolate are sugar, cocoa butter, cocoa solids (frequently added in the form of cocoa liquor—a blend of cocoa butter and cocoa solids), sugar, and dried or concentrated milk in various concentrations, cheaper versions may include one or more lower-cost fats in place of part or all of the cocoa butter. White chocolate typically includes sugar, dried or concentrated milk, and cocoa butter in various concentrations; again cheaper versions may also include a lower-cost fat in place of part of the cocoa butter. In both milk, dark and white chocolate, flavorings such as vanilla and other additives such as lecithin as emulsifier are frequently added. In traditional chocolate and chocolate products, cocoa butter and/or lower cost cocoa butter equivalent fats are added to cocoa liquor and mixed with other ingredients such as sugar, milk (in the form of powder or concentrate), emulsifiers and flavorings. The resulting melted chocolate is typically worked and heat treated (tempered) at well defined temperatures specific to each composition to ensure formation of desirable cocoa-butter crystal forms, and then typically cast and allowed to solidify. The thermal history and crystal forms determine, for example, the optical appearance and snappiness of the “snap” upon fracture. In addition to chocolate bars, which may also be porous, chocolate is frequently melted for it to be cast over or around a filling or coated onto ice cream, strawberries, or other edible inclusions.
Sugars are short-chain carbohydrates, typically with only one or a few saccharide monomers, including monosaccharides, disaccharides, and oligosaccharides. Simple sugars, or monosaccharides, include, for example, glucose (dextrose), fructose and galactose. Monosaccharides are the building blocks of disaccharides; to this group belong sugars such as sucrose (composed of covalently bonded glucose and fructose), lactose (glucose and galactose), maltose (diglucose) and trehalose (diglucose). Chemically similar to monosaccharides are the sugar alcohols, such as mannitol and sorbitol, which are often used as less nutritive sweeteners; for purposes of this document the term monosaccharide includes sugar alcohols. Oligosaccharides are composed of a few (typically three to nine) monosaccharides. Polysaccharides, typically not referred to as sugars but constructed from them, including starch, pectin, cellulose and chitin, are composed of long chains of monosaccharide units.
Disaccharides, oligosaccharides, and polysaccharides may be found in foods in intact form, and are often added to foods as thickening agents, or may be hydrolyzed into their component sugars. Examples of hydrolyzed polysaccharides commonly found in foods include corn syrup, high fructose corn syrup, and invert sugar. Invert or inverted sugar is a mixture of the monosaccharides fructose and glucose; invert sugar is obtained when sucrose is hydrolyzed into its two constituents. Invert sugar is sweeter than sucrose and is valued in candy making because it tends to retain moisture.
Honey produced by honeybees, is primarily composed of fructose and glucose, and, depending on the flower nectars that are used to make it, may also contain maltose, sucrose, and other complex carbohydrates. Some properties of honey resemble those of invert sugar.
Maple sap is traditionally collected in springtime from the xylem of sugar maple or various other species of maple trees; also some other species such as birch trees can be tapped to collect sap that is high in sugar content. Maple sap consists primarily of sucrose and water. Maple syrup is made from maple sap by dehydrating maple sap. It additionally contains small amounts of the monosaccharides glucose and fructose from invert sugar formed in the boiling process as well as other flavoring compounds.
Sugars are frequently ingredients in food, candy and confectionery. They are used and consumed in crystalline or glassy form, or when dissolved in a solvent such as water.
Chocolate is derived from fermented cacao beans, these beans are ground and fat, known as cocoa butter, is removed. The remaining solid portions are ground to form cocoa powder, a low-fat, finely ground, vegetable matter. Other seeds, including coconuts, walnuts, pecans, almonds, hazelnuts, and peanuts, can also be ground and fat removed to produce a finely ground, low-fat, vegetable matter. In some cases, finely ground vegetable matter may work even without removal of fat.
Chocolate may be cast around freeze-dried inclusions, such as freeze-dried strawberries or blueberries, however the pore structure of typical freeze-dried fruit is, in contrast to the materials described herein, may not be amenable to infiltrating (or impregnating) the fruit with the chocolate.
In freeze casting, as described by Heschel et al. in U.S. Pat. No. 6,447,701 and in our granted U.S. Pat. No. 8,877,498, an aqueous solution or slurry is prepared; a slurry may include water, or solutes with water in a solution, with additional particulate ingredients suspended in the water or solution. The solution or slurry is cooled to a sufficiently low temperature that ice crystals form within it. Since solutes and suspended particles tend not to be included in the forming ice crystals, these solutes and particles become concentrated between crystals where they form a composite, thereby ice-templating a 3D microstructure and architecture and producing a material with a self-assembled, hierarchical pore structure. Once frozen ice crystals are removed by lyophilization or freeze-drying.
An edible includes a directionally porous mass of at least one carbohydrate with a non-aqueous or a low-to-medium-moisture content infiltrate disposed within pores comprising at least one fat selected from melted chocolate, cocoa butter, butter, palm oil, coconut oil, or dairy cream. The edible is prepared by directionally freeze casting an aqueous solution or slurry including a carbohydrate; freezing the solution or slurry with directional crystal growth by applying low temperatures with a temperature gradient to the solution or slurry, and lyophilizing the frozen slurry. In embodiments, the solution or slurry includes fruit juice or puree, or finely ground vegetable matter such as almond flour, cocoa powder or peanut butter powder.
In an embodiment, an edible includes a directionally or partially-directionally porous mass of at least one carbohydrate with a low-moisture infiltrate disposed within pores comprising at least one fat selected from melted chocolate, butter, cocoa butter, coconut oil, palm oil, or cream.
In an embodiment, an edible is prepared by directionally freeze casting an aqueous solution or slurry including at least one carbohydrate; freezing the solution or slurry with directional crystal growth by applying low temperatures with a temperature gradient to the solution or slurry, and lyophilizing the frozen slurry to form a casting. In embodiments, the solution or slurry includes fruit juice or puree, or finely ground vegetable matter such as almond powder, cocoa powder or peanut butter powder. In embodiments, after lyophilization, the casting is impregnated with an infiltrate including melted chocolate, butter, cocoa butter, coconut oil, palm oil, or cream. The casting or infiltrate may contain water-soluble, oil-soluble or alcohol-based flavorings.
Directional Freeze-Casting
When freezing or freeze casting an aqueous solution or slurry, a temperature gradient may be applied to the solution or slurry and its mold, portions of slurry held at lower temperatures will tend to freeze more quickly than other portions, and ice crystals nucleated in these colder zones will grow along the thermal gradient into other zones as those other zones cool to below the freezing point of the slurry. In FIG. 33 of our issued U.S. Pat. No. 8,877,498 (Nov. 4, 2014), we describe a directional freeze-caster 100 also described with reference to
The mold, as illustrated in
The copper base plate 103 is then placed on top of the copper rod, or “cold finger,” which stretches down into a liquid nitrogen bath 110. The temperature at the top of the copper rod is monitored by a thermocouple 106 and temperature clines are regulated via a PID controller and a powerful heating element 108 near the top of the cold finger. In embodiments, the determined cooling rate is either 1 or 10° C. min-1, and cooling continues typically from 5° C. to a minimum temperature of −150° C. The determined cooling rate helps control a rate of ice-crystal growth in the sample, and thus control freeze-front progression as freezing progresses. As freezing progresses of slurry 112 in the freeze-casting mold 102, an ice phase (not shown) nucleates at the cold plate, and grows along the thermal gradient (here upwards) through the mold, concentrating solute and particles between the crystals thereby ice-templating it, thus forming a material. The material includes solutes and solids from the solution or slurry and has a hierarchical architecture whose pores are filled with ice. In a particular embodiment, each mold has a tubular shape with an inner diameter of 18.8 mm (¾ inch) and a height of 40 mm. Typical directionally freeze-cast materials have pore diameters between 10 and 300 microns measured perpendicular to the applied thermal gradient, but larger and smaller ones can be generated with selected freezing conditions; parallel to the applied thermal gradient, these pores may be as long as an entire casting.
When castings are fully frozen, they are removed from the cold finger, the samples are punched out of the mold using an Arbor press. The green casting is then freeze-dried for 48-72 h in a FreeZone 4.5 Liter Benchtop Freeze Dry System (Labconco, Kansas City, Mo.) to remove the ice phase.
In another embodiment of a directional freeze-caster, as illustrated in
In yet another alternative embodiment, one, two, three, or more separate coolant chambers 252, 254, 256 are formed around a central copper tube 258. Coolant, which in some embodiments is an ethylene glycol-antifreeze blend, chilled to appropriate temperatures by chilling devices (not shown) is placed in the coolant chambers. In an embodiment, the glycol-antifreeze blend is chilled to −40° C. A mold assembly including a copper mold bottom plate 260 and a mold 262, containing solution or slurry, is lowered into and slid through copper tube 258 at a rate determined to advance the freezing front within the solution or slurry at an appropriate rate.
A directionally- partially-directionally-, or if conditions are off a non-directionally-porous material is formed by a method 300 (
The carbohydrate solution is prepared by dissolving carbohydrate in water, or diluting liquid carbohydrate sources such as syrups with water, according to a particular recipe and contains edible carbohydrate such as a carbohydrate selected from one or more of sucrose, fructose, glucose, maltose, invert sugar, lactose, trehalose, maple sap, maple syrup or maple sugar, honey, corn syrup, methyl cellulose, sorbitol, mannitol, or mannose. The solution or slurry may in some embodiments contain carbohydrate thickening agents such as starch, pectin, or alginates; and in some embodiment protein-based thickening agents such as gelatin. Milk or milk products such as milk powder or sweetened condensed milk, may be used in the carbohydrate solution as a source of both carbohydrate and water. Flavor additives may include peppermint extract, vanilla extract, or similar flavoring solutions miscible with, or soluble in, water. It is noted that the processing described herein involves low temperatures so that volatile and heat-labile flavorings are retained in the product, and that the carbohydrates used in the solution may include both sweeteners and thickeners.
Prepared solution or slurry is placed 304 in a mold 102, 212 of the directional freeze-caster, and the solution or slurry is frozen 306 allowing directional crystal growth as heretofore described by using the freeze-caster to apply low temperatures with a temperature gradient to the solution or slurry. The frozen slurry is then lyophilized 308 to remove the ice crystals, leaving a directionally-porous scaffold or casting.
Once frozen and dried, castings containing sucrose, maple sap, maple syrup, maple sugar or other hydroscopic sugars are placed in a glass desiccation chamber with silica gel desiccant (−3+8 mesh granules, Alfa Aesar, Ward Hill, Mass.) with relative humidity 0.0 in order to keep atmospheric moisture from hydrating the sugar until such a time as they could be subjected to further processing such as infiltration, crushing, or consumption.
A non-aqueous or low-to-medium moisture infiltrate is prepared 310, typically based on an edible fat or oil. In an embodiment this infiltrate is a prepared milk, dark or white chocolate, in another embodiment it is cocoa butter, in another embodiment it is a fruit jelly; flavor and color additives may optionally be included. In alternative embodiments, other infiltrates based on flavored and/or sugared oils, such as butter, cream, coconut or palm oil are used. The infiltrate is melted by heating, with chocolate or cocoa butter infiltrates it is heated to a temperature above the melting point of the respective chocolate or cocoa butter. With castings based on a solution or slurry primarily containing short-chain carbohydrates or sugars, such as sucrose, fructose, or glucose, the infiltrate should be non-aqueous or have a sufficiently low moisture content so that it does not compromise the structure of the casting by dissolving the casting. Castings containing significant amounts of longer-chain carbohydrates that dissolve less rapidly, or protein gelling agents like gelatin, can tolerate a greater water content in the infiltrate.
The infiltrate is inserted 312 into the casting, we have found that not only the directional pores of the directionally or partially directionally solidified castings but also those of non- or semidirectionally solidified castings are typically amenable to absorbing many infiltrates by capillary action; infiltration with these infiltrates may be accomplished by placing an end in the melted infiltrate, and/or by fully immersing it in the infiltrate. In some alternative embodiments, vacuum-assisted or pressure assisted infiltration is used to expedite infiltration and permit infiltration with higher viscosity infiltrates such as whipped cream, jellies or white, milk and dark chocolate.
In some embodiments, an optional glaze or candy coating, such as a melted dark, milk or white chocolate coating, is then applied 314 and cooled as known in the confectioner's art.
In an alternative embodiment, instead of infiltrating the casting, the lyophilized casting is chopped or crushed 320 to form a crunchy particulate candy additive. This is added to a non-aqueous candy such as a melted chocolate that is then allowed to cool.
In an alternative embodiment, an infiltrated casting, or cut portions thereof, are included as a solid portion in a candy.
In alternative embodiments, non-infiltrated castings or cut portions thereof are included as solid portions in a candy.
In making prototypes, sugar solutions and sugar-solution/cocoa powder suspensions were prepared as 10 mL samples in 50 mL plastic cups or as 30 mL samples in glass ware. First, the respective sugar was weighed with a precision balance to within 1% accuracy. Maple sap, maple syrup and sugar solution concentrations of 5-20 vol. % were prepared. Note that some test castings were made from maple sap that had been raised in sugar concentration from the natural 2-3% to 8% by reverse osmosis. Solutions of different sugars were mixed, where appropriate, and any additional ingredients, such as cocoa powder, milk powder, almond powder, sweetened condensed milk or a combination of such substances, were added to the slurry according to the recipe, for recipes experimented with please see tables 1-8 below. Alcohol, if called for by a particular recipe, may be added. We believe that any ethyl alcohol used as a pore-size modifier is fully sublimated during the freeze-drying process, and thus does not remain in the final casting. The solution or slurry is finally thoroughly mixed before freezing. Some prototypes were hand mixed, others still were whipped into a foam before freezing.
The samples were typically prepared with a cooling rate of either 1° C./min or 10° C./min applied to the cold plate (bottom plate of the mold). In a particular embodiment, each mold has a tubular shape with an inner diameter of 18.8 mm (¾ inch) and a height of 40 mm.
A few sample castings (as listed in Table 2) were made using chocolate instead of cocoa powder, and successfully infiltrated with cocoa butter.
A few castings (as listed in Table 4, 5, and 8) having high solid content and having longer-chain carbohydrates as binder were successfully infiltrated with a commercial blackberry jelly diluted with water. While such an infiltrate would disrupt a simple monosaccharide or disaccharide casting, it is believed that the high solid content and long chains reduces casting solubility enough that the casting remains stable long enough to absorb the infiltrate.
Certain recipes resulted in freeze-cast and lyophilized materials having sufficient mechanical stability to undergo post-lyophilization infiltration. Recipes tested and results obtained are given in tables 1-8. In the tables, a Y in an infiltration column indicates successful infiltration of a casting with cocoa butter. A blank, UT, or Untested indicates an untested combination, a Y in a recipe column indicates successful production of a freeze-dried casting, where an X indicates casting failed or collapsed, and an O indicates a casting with problems such as excessive stickiness, highly irregular pore structure or partial collapse.
Ingredients used for experiments, and their sources, include:
100% Cocoa Butter; Venchi S.p.A. Via Venchi, 1-12040 Castelletto Stura (Cuneo), Piemonte, Italy
“Certo”, Premium Liquid Fruit Pectin; Ingredients: Water, Fruit Pectin, Lactic Acid and Citric Acid, Potassium Citrate, Sodium Benzoate; Kraft Foods Global, Inc., Northfield, Ill. 60093-2753, USA
Blackberry Jelly, Bonne Maman®; Ingredients: Blackberry Juice, Sugar, Cane Sugar, Concentrated Lemon Juice, Fruit Pectin; Andros Foods, F-46130 Biars, France
Maple Sap, Concentrated Maple Sap, Maple Syrup, Maples Sugar; Mt. Cube Sugar Farm, 1363 NH-25A, Orford, N.H. 03777, USA.
Justin's Chocolate Hazelnut Butter Blend; Ingredients: Dry Roasted Hazelnuts, Dry Roasted Almonds, Organic Cane Sugar, Organic Cocoa, Organic Cocoa Butter, Palm Fruit Oil*, Vanilla, Sea Salt; Justin's, 736 Pearl Street, Boulder, Colo. 80302, USA
Dr. Oetker, Instant Mousse Mix, Dark Chocolate Truffle Flavor; Dr. Oetker USA LLC, 10,000 Midlantic Drive Suite 107W, Mount Laurel, N.J. 08054, USA
Grated Sushi Wasabi. AFC Franchise Corp., 19205 S. Laurel Park Rd, Rancho Dominguez, Calif. 90220, USA
Sweetened Condensed Milk, Eagle Brand®. The J.M. Smucker Company, 1 Strawberry Lane, Orrville, Ohio 44667-0280, USA
Mott's® Natural Applesauce, Mott's LLP, Plano, Tex. 75086-9077, USA
Mott's® Original Applesauce, Mott's LLP, Plano, Tex. 75086-9077, USA
Cocoa Rouge Unsweetened Cocoa Powder; Guittard Chocolate Company, 10 Guittard Road, Burlingame, Calif. 94010, USA
Citrucel; GlaxoSmithKline, Consumer Healthcare, L.P., Moon Township, PA 15108, USA
Woodstock Organic Tomato Ketchup; Woodstock, 313 Iron Horse Way, Providence, R.I. 02908, USA
Heinz Tomato Ketchup; H.J. Heinz Co., L.P., Pittsburgh, Pa. 15222, USA
Nestle Carnation® Instant Nonfat Dry Milk, fortified with Vitamins A+D; Nestlé Baking, Nestlé USA, Inc, Solon, Ohio 44139 USA
King Arthur Flour, Almond Flour, Super Finely Ground & Gluten Free; The King Arthur Flour Company, Inc., Norwich, Vt. 05055, USA
Pomegranate Juice, R. W. Knudsen Pomegranate Juice Concentrate; Knudsen & Sons, Inc., Chico, Calif. 95927, USA.
For many of the sugars tried, it was found that there is a maximum percentage beyond which casting formation fails because of excessive stickiness and retained moisture during freeze-drying; better results are often obtained by diluting the material, or adding finely ground vegetable matter, prior to freeze-casting. For corn syrup used alone the sugar percentage should not exceed 40%, and invert sugar or maple sugar should not exceed 20%.
Table 1, Experimental recipes and results with sugars as carbohydrate phase, proportions in volume percentages.
Table 3, binders that can also be used alone to make castings
Table 4, additional combinations tested for casting production and infiltration.
Table 5, additional recipes
Table 8, almond powder compositions
The porosity of the freeze-dried material is determined in quantity, size and shape by the concentrations of sugar solutions and type and amounts of freeze-modifier additives, such as including the alcohol content of the slurry. Pore sizes may also be adjusted by altering the rate of freezing during the freeze-casting step of the process. Similarly, the pore aspect ratio depends on the solution/slurry composition and processing parameter such as the cooling rate and the temperature gradient along the mold during freezing or freeze casting.
In one series of experiments, pores averaged about 900 square microns in cross section. Pores are enlarged along the axis of freezing with most pores having lengths over 10,000 microns, and many pores extend through the entire 35 mm of an experimental casting, as illustrated in
Property gradients can be introduced in composition, adding solutions or slurries one after one another in the direction of freezing, with or without time for interdiffusion between the layers, by creating core-shell structures through successive freezing of first a shell and then a core, for example (either within a frozen or an already lyophilized shell, for example, or by changing the cooling rate during the freezing process or any combinations of these.
Combinations;
It is believed that any of the low-moisture infiltrates described herein, including melted dark, milk, or white chocolate, cocoa butter, palm oil and coconut oil, with or without added flavorings, are applicable to use with any casting recipe herein that produced a stable casting. It is also believed that higher-moisture infiltrates, such as diluted and flavored jellies, are adaptable to use with castings produced from recipes described herein that include long-chain carbohydrates such as methyl cellulose, nanocellulose, or pectin. While we have tested diluted applesauce—a puree of cooked apples—as a binder in both natural and sugar-added forms, we believe that castings can be achieved with many other fruit purees. Similarly, while one fruit juice was tested, we believe the method applicable to many other fruit juices and fruit juice combinations. Among specific combinations we believe functional are:
A method of manufacture designated A of an edible product including: preparing an aqueous solution or slurry containing at least one edible carbohydrate; freezing the solution or slurry with directional crystal growth by applying low temperatures with a temperature gradient to the solution or slurry to prepare frozen slurry; and lyophilizing the frozen slurry to prepare a casting.
A method designated AA including the method designated A wherein the solution or slurry includes fruit puree.
A method designated AB including the method designated AA wherein the fruit puree includes apple puree.
A method designated AC including the method designated A, AA, or AB wherein the solution or slurry includes fruit juice or fruit juice concentrates.
A method designated AD including the method designated AC wherein the fruit juice or fruit juice concentrates includes blackberry or pomegranate juice.
A method designated AE including the method designated A, AA, AB, AC, or AD wherein the solution or slurry includes at least one carbohydrate selected from the group consisting of monosaccharides and disaccharides.
A method designated AF including the method designated A, AA, AB, AC, AD, or AE wherein the solution or slurry includes finely ground vegetable matter.
A method designated AG including the method designated AF wherein the finely ground vegetable matter includes cocoa powder.
A method designated AH including the method designated AF or AF wherein the finely ground vegetable matter includes walnut, pecan nut, peanut, almond, hazelnut or coconut powder.
A method designated AJ including the method designated A, AA, AB, AC, AD, AE, AF, AG, or AH further including infiltrating the casting with an infiltrate comprising at least one fat selected from the group consisting of melted chocolate, cocoa butter, butter, palm oil, or cream.
A method designated AJA including the method designated AJ wherein the infiltrate comprises cocoa butter.
A method designated AK including the method designated A, AA, AB, AC, AD, AE, AF, AG, or AH wherein the slurry includes a long-chain carbohydrate and further including infiltrating the casting with an infiltrate comprising a jelly.
A method designated AL including the method designated A, AA, AB, AC, AD, AE, AF, AG, AH, AJ, or AK, further including applying a candy coating to the infiltrated casting.
An edible composition of matter designated B including a directionally-porous mass comprising at least one carbohydrate; a low-moisture infiltrate disposed within pores of the directionally-porous mass comprising at least one fat selected from the group consisting of melted chocolate, butter, cocoa butter, butter, palm oil, or cream.
An edible composition of matter designated BA including the composition designated B wherein the directionally-porous mass comprises desiccated components from fruit puree or fruit juice.
An edible composition of matter designated BAA including the composition designated BA wherein the fruit puree or fruit juice is selected from apple, blackberry, or pomegranate.
An edible composition of matter designated BB including the composition designated B, BA, or BAA wherein the directionally porous mass incorporates finely ground vegetable matter.
An edible composition of matter designated BBA including the composition designated BB wherein the finely ground vegetable matter comprises cocoa powder.
An edible composition of matter designated BC including the composition designated B, BA, BAA, BB, or BBA further including a candy coating.
The experiments herein described provide indications of a new way to make edible candies having texture and flavor combinations previously unknown in the art. In particular, we expect the intricate combination of porous, desiccated, aqueous phases containing carbohydrates, optional fruit purees, and potentially high percentages of cocoa, with pores infiltrated with non-aqueous and low-to-medium moisture phases such as melted dark, milk, or white chocolate or cocoa butter, to be of attractive and potentially novel textures and flavors.
While the embodiments have been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made without departing from the spirit and scope of the invention. It is to be understood that various changes may be made in adapting the invention to different embodiments without departing from the broader inventive concepts disclosed herein and comprehended by the claims that follow.
The present application claims priority to U.S. Provisional Patent Application 62/001,526 filed 21 May 2014, the entire contents of which are incorporated herein by reference.
The invention was made with government support under grant 1200408 awarded by the Civil, Mechanical and Manufacturing Innovation (CMMI) Division of the National Science Foundation. The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US15/32027 | 5/21/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62001526 | May 2014 | US |
