Egg protein product

Abstract

An expanded extruded high protein product comprising an extrudate of a composition comprising about 10-50% by dry weight of egg white and about 50-90% by dry weight of an edible starch, wherein the product has a moisture content of less than 8%, a protein content of at least 10%, and a density of less than 100 grams per liter.

Claims

1. An expanded food product comprising an extrudate of a composition comprising: about 25-50% by dry weight of egg white comprising egg protein; and about 50-75% by dry weight of an edible starch; wherein the expanded food product has a moisture content of less than 8%, a protein content of at least 30%, and a density of less than 90grams per liter, and wherein egg protein constitutes more than 50% of total protein in the product.

2. The product of claim 1 comprising an extrudate of a composition comprising about 25-40% by weight of egg white and about 60-75% by weight of an edible starch, wherein the product has a protein content of at least 30%.

3. The product of claim 2 comprising an extrudate of a composition comprising about 25-35% by weight of egg white and about 65-75% by weight of an edible starch, wherein the product has a protein content of at least 30%.

4. The product of claim 1 wherein the composition comprises a food grade protein source in addition to egg protein, said protein source constitutes less than 50% of total protein in the product.

5. The product of claim 1 wherein the product has a density of less than 50 grams per liter.

6. A method for making an expanded food product, the method comprising: mixing a batter suitable for extrusion by combining about 25-50% by dry weight of egg white and about 50-75% by dry weight of an edible starch, and a liquid, the batter having a protein content of at least 30%, wherein egg protein constitutes more than 50% of the protein; mixing a leavening agent into the batter at a dry weight of 0.01%-5%; mixing a food acid into the batter at a dry weight of 0.01%-3.80%; extruding the batter in an extruder wherein a temperature of a barrel of the extruder is increased from an input end to a discharge die thereof, wherein the temperature of the barrel of the extruder is increased from about 40° C. at the input end to about 175° C. at the discharge die; operating the extruder at a screw speed of between 300 and 800 revolutions per minute (rpm); and cutting product exiting the discharge die of the extruder to produce product particles of desired size and allowing the product particles to expand until the product particles have a density of less than 90 grams per liter.

7. The method of claim 6 wherein the batter comprises about 25-40% by dry weight of egg white and about 60-75% by dry weight of an edible starch.

8. The method of claim 7 wherein the batter comprises about 25-35% by dry weight of egg white and about 65-75% by dry weight of an edible starch.

9. The method of claim 6 wherein dry components of the batter are mixed together and then fed into the extruder, and liquid is added in the extruder to form the batter.

10. The method of claim 6 further comprising drying the product coming out of the extruder to a moisture content of less than 7%.

11. The method of claim 6 comprising operating the extruder at a screw speed of between 500 and 600 rpm.

12. The method of claim 6 wherein liquid egg white is used to provide the egg white and at least a portion of the liquid.

13. The method of claim 6 wherein the edible starch comprises at least one of rice flour, rice starch, pea starch, pea flour, corn starch, corn flour, wheat flour and wheat starch.

14. The method of claim 6 wherein the leavening agent is selected from the group consisting of carbonates, sodium bicarbonate, sodium phosphate, potassium phosphate, and calcium phosphate.

15. The method of claim 6 wherein the food acid is selected from a group consisting of citric acid, tartaric acid, malic acid, lactic acid, tannic acid, oxalic acid, benzoic acid and butyric acid.

16. The method of claim 6 comprising mixing one of a food color and a food flavor into the batter.

17. The method of claim 6 wherein the product particles have a density of less than 50 grams per liter.

Description

DETAILED DESCRIPTION

(1) The non-limiting description of a preferred embodiment of the invention is presented below with reference to high protein puffed snack product made from egg whites and the process for making the same. The percentages of the materials indicated below are by weight (dry basis) and the temperatures are in Celsius scale.

(2) The present invention has two main constituents. These include egg white and a starch. Several processing aids can be utilized to enhance the organoleptic properties and/or shelf life of the product of present invention. These are described below.

(3) Protein:

(4) Egg white is selected as the major source of protein in the current invention because egg protein offers best nutritional qualities as mentioned in the table above and its amino acid composition is similar to requirement for human. Egg protein has very high digestibility, and is practically free from objectionable odors and flavors. Egg white in liquid or dry state can be used. Dried egg whites can be manufactured by drum drying, spray drying or freeze drying either prior to using the protein and is commercially available and contains about 80% protein by weight.

(5) The egg white either dried or liquid is used in the present invention and forms between 10-50% of the blend with starch and other ingredients. Preferably, the content of egg protein is between 10-40% and more preferably between 10-35%. It is contemplated that the egg white could be combined with other animal or vegetable proteins like milk proteins (casein, whey protein), soy protein, wheat protein, oil seed proteins. These proteins could be either isolates or concentrates. Isolates are defined when the protein content is 90% or more. When the protein content is less than 90%, then the component is called concentrate.

(6) Starch:

(7) Starch for the present invention forms between 40-90% of the mix. Preferably, starch constitutes between 50-80% and more preferably between 60-80% of the mix. Starch is selected from a group of corn starch, potato starch, cereal flours (wheat, rice, oats, barley, rye, either alone or in combinations thereof). The starches could be native or modified starches. Corn starch is the most preferred starch for the present invention.

(8) Optional Ingredients:

(9) These optional ingredients may be used in making the food product of present invention and include: Leavening agent: A leavening agent may be selected from a group of carbonate, or bicarbonate or phosphate salts of sodium, potassium, calcium or magnesium. These agents can be used alone or in combinations thereof. These compounds are used at a level not exceeding 5%, preferably between 0.1-2.0% to improve the expansion and texture of extruded products. Food acids: Common food acids can be used either alone or in combination thereof at a level of not more than 10%. The foods acids include but not limited to citric acid, tartaric acid, malic acid, lactic acid, tannic acid, oxalic acid, benzoic acid and butyric acid. It is preferred to use citric or lactic acid at a concentration of 0.01-5.0%. Salts: Chloride salts of sodium, potassium, calcium or magnesium can be used either alone or in combinations thereof. The salts are used to improve the taste and flavor of the finished food product. When used, they are added at a concentration between 0-10%, preferably between 0.001-4% of the finished puffed food product. Sweeteners: Sweeteners can be optionally added to the formulation of the puffed food product either before extrusion or after extrusion and either before or after drying. Sweetener could be a part of the flavoring/coloring blend that may be applied by spraying/coating the dried food puffed food product. Sweeteners can be natural like sugars (including but not limited to sucrose, maltose, fructose, lactose, etc.), plant extracts like stevia, or synthetic including but not limited to aspartame, sugar alcohol (sorbitol, maltitol, erythritol, etc). Flavor: Flavors can optionally be added to the expanded puffed food product of present invention either before extrusion or after extrusion either before or after drying. The flavoring compounds can be the part of the mixture to be extruded or they may be sprinkled as is or coated/sprayed on the dried expanded food product. The technique of applying flavors are well known to people skilled in food processing. The flavors can be slected from synthetic or natural flavors. Organic versions of the flavors can be selected for the organic segment of the market. The flavors are selected from: Family of fruit flavors (like citrus including but not limited to orange, lemon, and varieties thereof), banana, apple, etc., Tropical fruit flavors, including but not limited to mango, peaches, lychee, kiwi, coconut, khus, etc. Berry flavors including but not limited to blue berries, strawberries, raspberries, chock cherries, etc. Floral flavors including but not limited to rose, jasmine, keora, etc. Spicy flavors including but not limited to anise, caraway, corrainder, turmeric, spearmint, peppermint, dill, peppers, cardamom, green tea, black tea, cinnamon, hickory, etc. Nutty flavors including but not limited to almond, cashew, peanut, etc. Dairy flavors like butter, cream, and/or cheese flavors Other flavors like chocolate, cocoa, caramel, etc. Synthetic flavors like bubble gum, etc. The flavors can be an extract, essential oil, oleoresin or fixed oil from different fruits/flowers/seeds, plants or a synthetic version of these flavors mentioned above. The flavors can be used either single or blended flavors. Flavors are added at a concentration of 0.0001-10% of the finished puffed food product. The concentration range of flavor depends on the type of flavor selected, time of addition to the product and also on the flavor choice of targeted consumer segment. Colors: Suitable food colors can be added to the finished product or to the blend prior to extruding. The colors include but not limited to natural colors (e.g. turmeric, beet, annatto extract, beta-carotene, grape skin extract, cochineal extract or carmine, paprika oleoresin, caramel color, fruit and vegetable juices, saffron or synthetic food approved colors like FD&C Blue Nos. 1 and 2, FD&C Green No. 3, FD&C Red Nos. 3 and 40, FD&C Yellow Nos. 5 and 6, Orange B, Citrus Red No. 2, Colors are added to enhance the visual appeal of the finished puffed food product. The concentration of colorant used in the formulation is dependent on the legal restrictions, colorant type, concentration of coloring agent and also on the time of addition to the product. Person skilled in the art of food processing understands the technique of coloring. Preservatives: Natural or synthetic preservatives may be added to the formulation to enhance the shelf life of the finished product. These preservatives are selected from a list of food approved preservatives in the amounts as governed by regulations or efficiency. The common preservatives are benzoic acid, sorbic acid, lactic acid, butyric acid, gallic acid and derivatives (salts/esters/ethers/or conjugates) thereof, butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT), tocopherols, tocotrienols, extracts of herbs including but not limited to rosemary, oregano, etc.

(10) Selection of processing aids is determined based on the process and equipment used for extrusion, form of packaging, intended use, etc. The processing conditions for production of high protein extruded, puffed product of present inversion will depend on the equipment, end product, desired packaging and market positioning. The common steps in processing of present invention include: (i) preparing a dry blend of protein and starch where protein is mainly egg protein supplied as liquid or dry egg white powder. Other protein sources may be added to the blend. When other protein sources are also used, egg protein constitutes more than 50% of total protein. (ii) Optionally adding other ingredients like color, flavor, texture and expansion enhancing agents, etc. to the dry mix, (iii) pre-condition the dry materials by adding water into the mixtures to optimum moisture content and/or to control material temperature prior entering the extruder, (iv) thermoplastic extrusion under controlled temperature and pressure to form an extrudate, (v) puffing the extrudate prior to cooling to form an expanded product, (vi) cooling at atmospheric pressure and temperature, (vii) Optionally drying to reduce moisture content and control the texture of the finished product; (viii) Optionally adding flavor and/or color to the puffed product.

(11) The chemical composition, expansion and functional properties vary depending on composition of ingredients, configuration and process parameters of the extruder. Leavening agent like sodium bicarbonate or calcium bicarbonate may be added to improve the expansion and texture of extruded products.

(12) The physical appearance can be altered through sizing, coloring, and like processes. The physical properties can also be altered by secondary processes such as dwell time, extrusion temperature, screw speed, pressure and drying temperature, etc.

(13) The screw speed of the extruder may vary depending on the extruded mixture formulations and is typically from about 300 to about 800 revolutions per minutes (rpm). Generally, as the screw speed increases, the amount of shear increases and extrudates become less dense. During extrusion, extrudates are conveyed under mechanical pressure in different heating zones prior to pushing through an extrusion die. The temperature of each heating zone is generally exceeds the previous heating zone by about 5° C. to 70° C. Extrudates are heated at 25° C. to 150° C.

(14) The pressure of the last chambers of the extruder barrel is important to the expansion rate and generally operated at between 35 bars to about 250 bars

(15) A method for making high protein expanded-extruded egg product comprises:

(16) (a) Preparing a mixture comprising about 10-50% by dry weight of egg white powder, or its equivalent in liquid form, and about 50-90% by weight of an edible starch, and adding water to form a batter or dough;

(17) (b) Thermo plastically extruding the batter under conditions of temperature and pressure such that the batter is melted and cooked to result in an extrudate;

(18) (c) The heated extrudate is forced through a discharge die under high pressure. As a result, extruded products released superheated steam, causing simultaneous expansion to the materials and a porous texture.

EXAMPLES

(19) Following formulations were prepared.

(20) TABLE-US-00002 Formulation 1 Corn flour 100%  Formulation 2: Corn flour 50% Egg white 50% Formulation 3: Corn flour 50% Egg white 40% Waxy corn starch 10% Formulation 4 Corn flour 50% Egg white 35% Waxy corn starch 10% Potato starch  5% Formulation 5 Corn flour 75% Egg white 25% Formulation 6 Corn flour 90% Egg white 10% Formulation 7 Corn flour 80% Egg white 20% Formulation 8 Corn flour 70% Egg white 30%
Procedure:

(21) Dry material of each formulation was mixed for 5-25 minutes in Hobert mixer. The mixture was transferred to hopper of twin screw extruder. Formulations 1 to 5 were prepared in Clextral Model EV32 (Clextral SAS, Z.I. de Chazeau, BP 10, 42702 Firminy Cedex, France,) twin screw extruder while formulations 6-8 were prepared in Clextral model EV58. Water was added to the extruder at a rate of 4-7 kg/hour.

(22) Such extruders are generally operated at 300 and 800 revolutions per minute, and for these examples the screw speed was adjusted to 500-600 rpm. Die temperature was maintained between 130-150° C. and the cutter speed was maintained between 1000 to 1500 rpm. Typically these extruders allow for temperature control at different levels along the barrel and to achieve expansion it is generally known that the temperature should be increased from the input end of the barrel to the discharge die thereof. In these examples the temperature of different barrel zones 1 to 5 of extruder was maintained at 50, 90, 110, 130, and 150° C.

(23) The product of formulation 1-5 coming out of die was dried in hot air oven at a temperature of 160-195° C. for 2-6 minutes to a moisture content of 2-6%. From the results of experiments mentioned above we unexpectedly found that up to 50% egg white addition to corn starch resulted in expanded product, suitable for snack applications while the egg protein concentration higher than 50% produce the products with poor expansion. For cheesy or popcorn type texture, up to 40% egg white was found suitable. The density of all products varied from 47 to about 100 grams per litre.

(24) In another series of experiments, we replaced egg white with whole eggs in same concentrations. The resultant product was more dense and expanded poorly compared to products made using egg white in same concentrations.

(25) Another series of experiments was conducted to study the effect of lavening agent and food acid on the formulation. The experiments are outlined below:

(26) TABLE-US-00003 Composition Formulation Sodium Code Egg white Corn flour Citric acid bicarbonate E30408-1 40.00% 60.00% E30408-2 40.00% 59.50% 0.50% E30408-3 40.00% 58.00% 2.00% E30408-4 40.00% 58.00% 2.00% E30408-5 40.00% 56.00% 2.00% 2.00% E32028-1 35.00% 65.00% E32028-2 35.00% 64.75% 0.25% E32028-3 35.00% 64.50% 0.50% E32028-4 35.00% 64.00% 1.00% E32028-5 35.00% 64.50% 0.50% E32028-6 35.00% 63.50% 0.50% 1.00% E32028-7 35.00% 64.00% 0.50% 0.50% E32028-8 35.00% 63.75% 0.25% 1.00%

(27) The dry ingredients were mixed in a hobert mixer for 5-20 minutes. The dry mix was transferred to the hopper of the twin screw extruder. Water was injected into the barrel of extruder and the temperature was maintained between 50 and 175° C. and the pressure was between 5-250 bar. The material extruding through the die was cut and dried in oven at 70-90° C. for 1-3 minutes.

(28) The products obtained in the above series of experiments had crunchy, crispy taste with nice mouth feel and organoleptic properties. Batch number E30408-3 had sour taste and was comparatively denser than other products.

(29) This series of experiments suggested that levels of leavening agent and food acid can be adjusted to obtain the product of desired mouthfeel, texture and shape. The product could be coated/sprinked with various flavors to further improve the organoleptic properties.

(30) Other starches could be combined with the egg whites as well in varying proportions to form suitable expanded egg protein products. It is contemplated that other food grade protein source material could be added to egg white powder. The expanded egg protein product is versatile and has a wide range of food applications. It is contemplated that flavoring and other treatments known in the art can be applied to the product to produce a wide variety of foods including snack foods e.g. chips, crackers, and breakfast cereals.

(31) The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.