Patent Application
20130344227
The present invention relates to a new food product and to a product for treating food and for enhancing food safety by extending shelf-life, the method of manufacture of the class of products and a method of treating food using the product for the purposes of extending shelf-life.
Food safety is an imperative in the pre-packaged foods market. Pre-packaged foods are a multi-billion dollar world-wide industry; and ready to eat (RTE) chilled prepared foods represent a sizable portion of that market. One of the primary obstacles to offering certain foods in a pre-packaged, RTE, format is limited shelf-life.
Shelf-life is a key factor in determining food safety and for developing food products. Longer shelf-life means larger ranges of shipping and larger markets. Shelf-life also leads to consumer satisfaction and safety. Government regulations may also stipulate minimum shelf-life labelling requirements.
A variety of existing techniques have been developed for the preservation of food, including wrapping in plastic, embedded preservatives, sterilization of packaging and food prior to wrapping, and food coatings.
However, in the case of certain foods which readily undergo natural, aerobic, decomposition (like fish/seafood, eggs, meat and poultry) shelf-life is generally considered to be limited as compared to other ready-to-eat products.
Natural foods which include dairy are part of a healthy diet, and are generally recommended by national food guides, but in its natural state, is also subject to short shelf-life.
There is also a desire to achieve freeze thaw stability of dairy based emulsions to permit long term storage and use. Emulsions which lack freeze thaw stability lose their homogeneous structure rendering them visually unpalatable to consumers.
There is a desire in the market for novel dairy based food products for use in spreads and dips.
There is a desire for an edible, shelf-life extending product for the preservation of foods which may be coated, placed in chilled prepared format.
There is a desire for an edible coating which preserves food shelf-life, so as to permit a wider variety of products to be offered in pre-packaged form.
There is a desire for a food preservative which would permit proteins to be used more reliably in chilled prepared state, including proteins such as poultry, meat, seafood, including as a pre-packaged dip.
The present inventions are a food composition, a food shelf-life extending emulsion, a method of manufacture for the food (whether or not used as a shelf-life extending emulsion) and a means of application of the food shelf-life extending emulsion to preserve food. Another goal of the present inventions is to advance food science and safety using stabilized dairy-based emulsions developed to prolong product shelf life. The food composition is an an emulsification matrix of an oil in water emulsion further comprising stabilizing emulsifiers such as dairy fats and proteins, gums and fibers having an average micelle diameter predominantly between 3 microns and 40 microns, and having an median micelle between 2 and 5 microns, and average (by volume) of between 5 microns and 20 microns; and having total saturated and unsaturated fat content ranges of 10-50%, water content from 10-80% of the total weight, viscosity range of 15,000-120000 centipoise. The acidity in the product is adjusted during manufacture to between approximately 2.8 pH and 5.5 pH. High shear during the mixing process results in a stable emulsion with very small particle size. Food coated with the matrix has been shown to have extended shelf-life.
Based on testing, the composition achieves extended shelf-life over other products in the market formed of similar ingredients. It is hypothesized, that the enhanced shelf-life is achieved in at least one of five of the following possible ways: 1. intrinsic nature of the matrix, the micrometer level micelle size, and complementary added proteins have a hydrophilic/hydrophobic interaction on the molecular level which appears to extend the shelf-life of the added proteins beyond typical ranges; 2. at the micrometer level, gas bubbles at the food surface are minimized and little to no oxygen is available for aerobic decomposition; 3. naturally occurring anti-microbials in the oils and matured dairy products are more effectively dispersed throughout the emulsion; and 4. the pH of the emulsion is modified during the manufacturing process to a controlled pH level, which may further extend shelf-life; and 5. A nitrogen or argon blanket is optionally applied during processing to further assist in reducing oxygen content within the matrix and on the food.
In one aspect, the composition of the present invention is a novel high shear emulsification matrix comprising water, edible oils, modified starch, xanthan gum, egg whites and fat. The fats may be dairy products. The dairy products may be chosen from a set of dairy products including, cheeses, sour cream, cream cheese, cream, butter, yogurt and others.
In another aspect, the invention is the use of the composition described herein for coating proteins for the purposes of extending shelf life of food products including the coated proteins.
In another aspect, the invention is the use of a form of the composition described herein as a mayonnaise substitute.
In another aspect, the invention is the use of a form of the composition described herein as a dressing.
In another aspect, the invention is the use of a form of the composition described herein as the base matrix for a flavoured dip, or other food stuff normally using a cream cheese or whipped cream cheese base.
In another aspect, the invention is a method of manufacturing the composition. The composition end product can be described as a high shear, dairy based emulsification matrix manufactured according to the following steps.
First, the original emulsions of selected creams, butters and cheeses are broken down during a high shear homogenizing step and then re-emulsified with the other ingredients added at this stage. Here, the dairy components are mixed together with oils and waters for 3 to 5 minutes. The input products may be heated during this step. Standard mixing speed or shear in this stage is possible, but high shear—1800 to 5000 rpm—may also be employed for convenience.
Second, the salts and acids are added and mixed therein for 2 minutes. Again, either standard mixing speeds or high shear speeds may be employed, and the mixture may be heated from ambient temperature.
Third, the gums and starches are added to the composition and mixed at high shear for 3-5 minutes at a temperature of between 50 degrees Celcius and 100 degrees Celsius, into a stabilizing matrix.
Fourth, after the stabilizing matrix is created, egg whites are added and the composition mixed or stirred for 2 to 5 minutes at approximately 50 degrees Celsius to 100 degrees Celsius at mixing speeds of under 1800 rpm. Other proteins may be added in this step, being coated by the mixture.
Temperature during processing typically ranges from 4 degrees Celsius to 70 degrees Celsius in steps 1 and 2, step 3 may be at approximately 70 degrees Celsius, and step 4 at approximately 80 degrees Celsius, Emulsion stability is directly related to shear force and corresponding decreasing diameter of the micelles of the particles of the resulting composition. Shear speeds of 1800 to 5000 rpm are required during the step in which the gums and starches are added. Shear speeds of 1800 to 5000 rpm may be employed during the earlier processing stages for convenience, but are not recommended during the additional of egg whites and optional proteins.
The process of the present invention homogenizes and recombines existing emulsions into a novel, more stable emulsion with supporting matrix with micelles in a 1-20 micron range that has the advantage of being able to protect larger food particles from decomposition, and in particular aerobic decomposition. Particle size ranges predominantly less than 6 microns (averaging about 7.7 microns by volume) and predominantly on the order of 2 to 5 microns have been shown to be achieved using the production method described.
Advantageously, the emulsified matrix of the present invention is adaptable in terms of viscosity; texture and mouth feel by varying the core ingredients and shearing rates. Having a broad range of physical adaptation means it could be potentially used in multiple food categories.
The macro encapsulation process of the present invention is stable following freeze thaw, and is anticipated to provide shelf-life extension to any of the following categories; however it has only been demonstrated for seafood. Any modifications required to adapt the invention to any of the following categories should not limit the disclosures in respect of those categories for which the invention operates as claimed: (a) fruits and vegetables: fresh/frozen and/or preserved in any form; (b) entire frozen food category: whether raw/prepared and/or ready to serve, etc.; (c) meat/poultry/fish/seafood of any kind, and-or form: raw-fresh and/or cured/or partially and/or fully cooked as is; or alternatively as ingredient such as protein based salads; sandwich fillings; “pies” etc.; (d) all “Deli” category and related products whether (home meal replacement—HMR) prepared meals (uncooked or cooked) and/or salads/pizza/etc.; bakery based products: bread/cookies/cakes, etc.; (e) all Dairy/non-dairy based products; including any form of cheese/milk/butter or alternatively-based utilizing soy; (f) pasta and pasta-based products; (g) sandwiches of any kind/hamburger and/or related products; (h) fast food industry whether subs/burgers/tacos/protein and non-protein based products/bakery and/or bakery related/ice cream; dairy and non-dairy based; (i) food service—all categories: protein based/bakery based/soy based/and any form of beverages; and (j) spreads/preserves: of any kind including: peanut butter/jam/marmalades; pickles, etc.
The compositional ingredients include: fat selected from soft or hard fats; vegetable oils which are liquid at ambient room temperature, one or more egg white containing material; one or more edible acids; starches; gums; and water. The fat may be a dairy product, including cheese, cream cheese, sour cream, cream, butter, yogurt, etc. An anti-microbial or other preservative, such as potassium sorbate, edible acids or suitable alternative may also be added within the scope of the present invention, or may be present in the input fats or egg white containing material.
The fat is present at a level of from about 10% to about 50% by weight. Suitable fats may be any food grade fat, including: palm kernel oil; cocoa butter; nut butters; dairy fats including, cheese, sour cream, cream cheese, butter, processed cheese, cream or others.
The vegetable oil may be any of the well recognized food oils, including without limitation as soybean oil, corn oil, cottonseed oil, peanut oil, other nut oils, olive oil, canola oil, sunflower seed oil and other. Vegetable oil should be present at a level preferable less than 10%.
The edible acid, acidifying salt, or fatty acid ester is preferable chosen from the group of edible acids, acidifying salts or fatty acid esters consisting of: acetic acid (vinegar), ascorbic acid (vitamin C), citric acid (lemon juice), and the edible salts and fatty acid esters thereof. These should be added in sufficient quantities to produce the desired taste of the end product at a coating pH of from about 2.8 to about 5.5, to provide for an end food product with a suitable pH level.
The starch can be any smooth, short textured and heavy bodied edible starch, in practice, and testing revealed that modified starch, including without limitation Colflo 67™ and Frigex W™ provided usable product. The starch should be largely unaffected by the desired pH. Starch can be present at a level of from about 0.5% to about 10% by weight, as a thickening agent and to adjust texture.
Added gums, such as xanthan gum, are present in very small amounts (0.01% to 1% by weight), adjust texture.
Optionally, an egg white containing product is present at a level sufficient to provide from about 1% to about 10% egg white protein by weight, to achieve desired rigidity to the composition. As the addition of egg whites, adds volume in the mixing stage, using an inert gas blanket while the egg whites are being mixed provides additional benefit to excluding possible oxygen within the matrix.
Water is present in a quantity sufficient to provide the desired viscosity in the range of 15000-120,000 centipoise, generally achieved with 10-50% of the total weight being water.
High shear is necessary to form micro-particles of the saturated fats and suspended oils to ensure macro encapsulation of food products by an encompassing layer of the inventive coating. Shear speeds of 1800 to 5000 rpm may be employed throughout the processing stages, but are required only in the stage at which gums and starches are added if the other stages are mixed more slowly. These shear speeds can be achieved in appropriate temperature ranges using a Silverson™ or comparable high shear, in-line or other homogenizer.
Certain embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings.
In order to demonstrate the physical characteristics of the composition of the present dairy based emulsion, and its shelf life, batches were prepared according to the following method and tested.
The emulsification matrix used in testing was manufactured as follows:
The testing discussed below has demonstrated stability for freeze thaw cycles to −85 degrees Celsius with a shelf life of at least 56 days at 4 degrees Celsius. The cumulative volume of particles sizes within the matrix are shown to have a predominantly log-normal distribution centred on approximately 7.7 microns, with 95% of the particles of that size between 2 microns and 40 microns; with 94% of the particles by number being below 6 microns.
Preliminary physical and microbiological tests demonstrate that the emulsion of the present invention used to protect seafood in a dip has a refrigeration temperature shelf-life of at least 56 days.
Testing of the emulsion of the present invention was conducted at the PEI Food Technology Centre, now referred to as Bio/Food/Tech, in Charlottetown, PEI, Canada. The goal was to compare the effect of high shear emulsification to regular mixing on quality and stability of the products. This testing involved monitoring the changes of product qualities by physical and microbiological tests during 56 days storage at refrigeration temperature, as well as a rapid thaw cycle microbiological test.
A sample of the emulsification matrix was prepared according to the following specifications and tested on the foods indicated in the tables below.
A Freeze-thaw test of the high shear emulsion was used to compare differential high shear speeds and types of starch. Four 200 g batches using the food product of Sample 3 with two starch samples from National Starch (Colflo 67™ & Frigex W™) were made following the process noted above and a third batch with no cilantro, red pepper (fresh), seafood and egg white. Two shear mixing speeds were tested: 1800 rpm and 3600 rpm. Samples were used for a freeze-thaw cycle test. About 30 ml of sample was put into a 50 ml plastic container, covered with a cap, and put in a −18° C. freezer. After 24 hours, samples were taken out of the freezer and set on the counter-top (room temperature) to thaw. Visual observation was done for any change on the composition.
Then, six samples made with 2 mixing speeds (regular mixing and high speed 3600 rpm) for each of the three products with seafood and six samples without seafood and egg white. Samples with regular mixing speed were hand stirred. Samples were put in a −18° C. freezer overnight then put in a −85° C. freezer for 1 hour, thawed at room temp and visual observation done to determine any change.
There was no visible difference between Colflo 67™ and Frigex WT™. Samples made at 1800 rpm had slight water phase separation. Based on these observations, Colflo 67™ was selected for further testing at a mixing speed of 3600 rpm for the high shear mixing steps.
As between the samples of a composition of the same ingredients created by regular mixing and high shear mixing, the samples without seafood & egg white were thinner than the samples with seafood & egg white and exuded more water after a freeze-thaw cycle. For samples with seafood & egg white, the high shear mixed samples were thicker than the regular mixed samples. Both regular speed mixed and high shear mixed samples were stable for the freeze-thaw test.
A microbiological stability study was also performed on foods prepared using the present invention. Three 2000 g batches of each of 3 sample food products were produced and a portion of each batch was packaged to fill 16 100 g PETE bottles with lids. There were 16×100 g bottles in each batch. Three types of tests were carried out for the microbial stability study.
The first test was an accelerated thaw carried out at 36° C. At 0, 7, 24 and 30 hour TAPC was tested. Table 2 shows the outcome of the second test confirming microbiological stability of the compositions of the present invention.
The second test was exposure test by opening packages and then closing them again, and storing the samples at 4° C. for 65 hours. At 0, 24, 48 & 65 hour TAPC was tested. Three readings of pH measurement for each sample were taken at all sampling times using an Orion 3 Star Benchtop pH Meter (Thermo Electron Corporation, Beverly, Mass.).
The third test involved weekly examination of each batch stored for 8 weeks at 4° C. At week 0 Total Aerobic Plate Count (TAPC), Listeria, B. cereus, & Staph were tested. At weeks 1 to 7 TAPC only was tested. At week 8 TAPC, Psychrotroph, B. cereus, & Staph were tested. Table 4 shows the outcomes of the third test, confirming microbiological stability of the compositions of the present invention.
B. cereus
S. aureus
B. cereus
S. aureus
During 8 weeks storage at 4° C., samples of the three products with the original client formulae made with high shear mixing were satisfactory for Microbial tests.
Further continued testing of the batches demonstrated that as a preservative, the shelf-life of encapsulated seafood products in the test batch samples actually outlasted 96 days.
The composition described herein, while being comprised of an emulsion of dairy products, shows longer shelf-life than its constituent dairy product elements which have not undergone the process, and the seafood also does not spoil as quickly when coated by or embedded in the emulsification matrix.
In a slightly different formulation within the scope of the processes set forth herein, a smaller sample (176 gram (10 oz)) of an emulsification matrix of the form described herein was manufactured using the following ingredients and ratios: 50 g (1.75 oz) sour cream, 22 g (0.75) oz cream cheese (Philadelphia™ brand), 42 g (1.5 oz) cream (18%), 28 g (1.0 oz) water, 14 g (0.5 oz) soy oil, 14 g (0.5 oz) egg whites, 1.55 g sea salt, 1.75 g sugar, 1.7 g vinegar, 0.6 g starch (Colflo 67™ brand), 0.2 g Xanthan gum, 0.075% w/w (0.45 g) potassium sorbate, 0.2 g citric acid.
In a first mixing step, the sour cream, cream cheese, cream, water and soy oil were shear blended at a mixing speed of 1800 rpm to 5000 rpm at a temperature of approximately 70 degrees Celsius for up to 5 minutes until liquefied. In a second mixing step, the sea salt, sugar, vinegar, potassium sorbate and citric acid were then added and shear blended at a mixing speed of 1800 rpm to 5000 rpm at a temperature of approximately 65 degrees Celsius for approximately 5 to 7 minutes. In a third mixing step, the starch and xanthan gum were then added and shear blended at a mixing speed of 1800 rpm to 5000 rpm at a temperature of approximately 65 degrees Celsius for approximately 7 to 12 minutes. In a fourth mixing step, the egg white materials were added and blended, without shearing, at a temperature of approximately 80 degrees Celsius for approximately 12 to 16 minutes. The product was then cooled to below 4 degrees Celsius for testing.
The base mixture would then have been suitable for mixing with a protein for use in a pre-packaged food such as a dip or sandwich spread. Instead, a portion was used for micelle particle size testing and another portion was subject to visual inspection under a microscope to confirm.
The illustrated embodiments are only examples of the present invention and, therefore, are non-limiting. It is to be understood that many changes in the particular structure, materials and features of the invention may be made without departing from the scope of invention as expressed in the claims and described herein.
This application claims priority to U.S. Provisional Application No. 61/450,447 filed Mar. 8, 2011, the contents of which are hereby incorporated by reference in their entirety.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CA2012/050133 | 3/6/2012 | WO | 00 | 9/9/2013 |
| Number | Date | Country | |
|---|---|---|---|
| 61450447 | Mar 2011 | US |
