CN113950253A - Method for separating protein composition and fat composition from bone-removed poultry meat - Google Patents

Abstract

A method for recovering protein fraction and oxidation stable fat fraction from poultry meat containing fat, bone and protein is provided. Poultry meat is comminuted and solubilized with a food grade acid or base to form a liquid protein fraction and a solid fat fraction. The protein in the liquid fraction is precipitated and the protein product retains the color of the raw meat.

Description

Method for separating protein composition and fat composition from bone-removed poultry meat

Reference to related applications

This application is U.S. application No. 16781116 entitled "Process For Isolating a Protein Composition And a Fat Composition From bound canister" filed on day 4.2.2020 by Stephen d.kelleher et al (which application claims priority of U.S. provisional application No. 62800754 entitled "Process For Isolating a Protein Composition And a Fat Composition From bound canister" filed on day 4.2.2019), And this application is continued U.S. application No. 12 filed on day 27.7 by Stephen d.kelleher et al (which application is named "Process For Isolating a Protein Composition And a Fat Composition From bound canister" filed on day 27.12.2017. the application No. 3 entitled "Process For Isolating a Protein Composition And Fat Composition From bound canister" filed on day 11.3.7. the application No. 12 For Protein Composition And Fat Composition 1 Fat Composition No. 3 filed on day 3.7.3.3.7.7.7.7.7.3.3.7.7.7.7.3.7.3.7.3.3.3.3.7.3.3.7.7.3.7.7.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3 A partial continuation of U.S. application No. 13/374,398 to mechanical deboned canister ", which claims continuation of U.S. provisional application No. 61/460,324 entitled" Process for isolating a protein composition and a fat composition from meal composition ", filed on 3.1.2011 by Stephen d.kelleher et al); and this application is U.S. application No. 15217984 entitled "a Process for achieving a bean Protein" filed on 23/7/2016 by Stephen d.kelley et al (which is U.S. application No. 14872279 entitled "Protein Composition achieved From meal strategies" filed on 1/10/2015 by Stephen d.kelley et al (which is a continuation of U.S. application No. 2011 13374077 entitled "Process for isolating a Protein Composition and a fat Composition From meal strategies" filed on 12/2011 by Stephen d.kelley et al, which claims a temporary continuation of U.S. application No. 61/460,324 entitled "Process for isolating a Protein Composition and a fat Composition" filed on 3/1/2016 by Stephen d.1 kelley et al). The entire teachings of the above application are incorporated herein by reference.

Technical Field

The present invention relates to a method for separating a protein composition and a stabilized fat composition from a fat (fat) containing deboned poultry meat (e.g., manually or mechanically deboned poultry meat) containing animal muscle tissue. More specifically, the invention relates to a process wherein animal muscle tissue is solubilized in acid or base and the thus obtained solubilized liquid protein composition is separated from solid animal fat and impurities under the following conditions: (a) reducing calcium content, (b) reducing sodium concentration, (c) reducing oxidation and/or (d) maintaining its functional properties, including color (e.g., its raw meat color or red color).

Background

Currently, protein recovered from animal muscle tissue is obtained by solubilizing animal muscle tissue in an edible acidic composition (such as citric acid, hydrochloric acid, or mixtures thereof). Such methods are disclosed in U.S. patent 6,005,073; 6,288,216, respectively; 6,451,975, and 7,473,364. While these methods are well suited for recovering proteins from animal muscle tissue, they may have drawbacks when extracting proteins from starting materials with high bone concentrations. Of which is mainly a potentially large amount of calcium, which is initially present in the native bone material, which is incorporated into the final meat product. The final meat product contains bone and may or may not be mechanically deboned to separate most of the bone from the meat. These bone-containing meats contain a high concentration of animal muscle tissue, typically between 65-85% by weight, with the remainder of the composition comprising primarily fat and bone. Mechanically deboned poultry meat may also contain significant amounts of blood, which is the component that provides hemoglobin and its constituent iron/heme molecules to the mixture. Microgram levels of heme pigment have been found to be a controlling factor in fish oxidation. Thus, there is a need to recover protein from animal muscle tissue for use as a food additive rather than discarding it. There is also a need to recover purified and stabilized fat from bone-containing poultry meat, such as mechanically deboned poultry meat, which has economic value as a food additive.

There is a need for improved methods and compositions for treating deboned poultry meat.

Disclosure of Invention

The present invention treats deboned poultry meat (e.g., manually or mechanically deboned) derived muscle tissue in a manner that preserves the function of the recovered protein product. Protein functions of most interest to food scientists are color, solubility, water retention capacity, gelation, foam stability and emulsification properties.

In addition, the process of the present invention treats animal tissue in a manner that produces a final product with large fibers that results in better yield and has a better final product texture.

In one embodiment, the present invention also provides a method of producing a fat fraction having a relatively low concentration of water and that is stable to oxidation. This form of fat allows it to be added to various food products.

The U.S. government specifies that certain quality meat products obtained from animal trim (trimming) may be used in the same species of meat product without statement. For example, "fine textured beef (fine textured bean)" and "fine textured lean beef (lean textured bean)" may be used in ground beef without being declared on a label. In one embodiment, the protein composition of the invention is "fine textured meat" (FTM) having a fat content of less than 30 wt%; a protein content of 14 wt% or more; the Protein Efficiency Ratio (PER) is 2.5 or more, or the content of Essential Amino Acids (EAA) is 33% or more of the total amino acids. In one embodiment, the present invention also results in "fine-grained Lean meat" (LFTM) having a fat content of less than 10% by weight, and meeting other requirements for "fine-grained meat".

Accordingly, the present invention provides a method for separating animal muscle protein from fat-containing animal tissue containing animal muscle tissue, such as from bone-containing poultry meat, including mechanically deboned poultry meat, and provides high yields of functional animal muscle protein while significantly destroying microorganisms. Furthermore, in one embodiment, the present invention also provides a fat product from bone-containing poultry meat (such as deboned poultry meat) that is stable to oxidation and has a relatively low water concentration. In addition, the invention provides animal muscle protein products having a similar or reduced sodium content as compared to the original meat. In addition, the present invention provides a method of eliminating undesirable odor characteristics, such as ammonia odor. In addition, the present invention produces a final meat product with large fibers that result in a more desirable ground meat-like texture and mouthfeel. Such a process would provide high recovery of oxidation stable fat and animal muscle protein in a low microbial environment while avoiding the addition and retention of ingredients that adversely affect the edibility of the protein product.

In accordance with the present invention, a method is provided for separating animal muscle protein and oxidation stable fat with preserved functional raw meat color (e.g., "red" or "reddish" color). The protein product is obtained from bone-containing poultry meat, such as mechanically/manually deboned poultry meat having animal muscle tissue and fat. The process provides a high yield of functional animal muscle protein with preserved and functional color (raw meat color) while avoiding problems due to the presence of microorganisms and avoiding the problem of making the recovered protein inedible. The method of the invention also provides a fat product that is stable to oxidation and contains a relatively low water concentration. The method of the invention results in an animal tissue product that meets the U.S. government definition for beef and extends to "fine grain meat" or "fine grain lean" for poultry meat.

The method comprises the following process steps: grinding fresh or frozen poultry meat containing bone (such as manually deboned poultry meat or mechanically deboned poultry meat), adding cold drinking water to the ground poultry meat; optionally adding a food grade acid or a food grade base simultaneously; homogenizing the comminuted poultry meat-water mixture; food grade acids or bases are added to the homogenous mixture to solubilize the proteins. In the case of an acid, the pH of the homogeneous mixture is lowered such that the pH of the resulting mixture is between about 3.6 and about 4.4 (e.g., about 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4), preferably between about 3.6 and about 3.8, to solubilize animal muscle tissue. In the case of a base, the pH of the homogeneous mixture is increased such that the pH of the resulting mixture is between about 8.3 and about 10.5 (e.g., about 8.4, 8.5, 8.6, 8.7, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4). In other words, this step may refer to adjusting the pH of the comminuted poultry meat to solubilize the protein to obtain a solubilized liquid protein solution, wherein said pH adjustment for solubilizing the protein comprises adding a food-grade acid to obtain a pH value in the range of about 3.6 to about 3.8 or adding a food-grade base to obtain a pH value in the range of about 8.3 to about 10.5, thereby obtaining a solubilized liquid protein solution. During this step, the calcium remains insoluble. The process of the invention comprises separating solid fat from a solubilized (acidic or basic) animal muscle protein solution and recovering the solid fat. In this step, calcium is separated from the solubilized protein together with solid fat, thereby obtaining a fat-reduced solubilized liquid protein solution. The process of the invention further comprises optionally evaporating water from the solubilized animal muscle protein solution to form a concentrated protein solution, and recovering the animal muscle protein solution. The method further includes precipitating proteins in the reduced fat solubilized liquid protein solution by adding a food grade alkaline composition (if solubilized using an acid) or a food grade acid composition (if solubilized using a base) to the animal muscle protein solution to a pH of about 4.9 to about 6.4 (e.g., 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4), preferably about 5.2 to about 5.8, to form a salt from the reaction of the acid and the alkaline composition and precipitate the proteins. During precipitation, sodium remains soluble. The method can further comprise separating the solid protein from the remaining liquid, e.g., by centrifugation and/or screen filtration, and optionally freezing the precipitated animal muscle protein composition. After undergoing the method, the protein composition of the invention has 14 wt.% or more protein and less than 10 wt.% fat, wherein the less than 10 wt.% fat is stable to oxidation.

It has been found that when the pH of animal muscle tissue is lowered from 3.6 to 4.4 or raised to 8.3 to 10.5 according to the invention, the animal muscle tissue is solubilized while substantially maintaining its original color (functional green meat red/reddish) and a satisfactory yield of muscle tissue (protein) is obtained. For beef, the animal muscle tissue protein product has a color of 75-52L, 25-15a, and 23-16b, where L, a, and b are defined as L (lightness) or muscle brightness (CIE), a (redness) or muscle redness), b (yellowness) or muscle yellowness according to the Commission Internationale de I' eclairage (CIE). For poultry meat, the animal muscle tissue protein products have a color of 82-45L, 7.5-2.2a, and 20-3 b. For example, in the case of beef and poultry muscle tissue, the original color is substantially preserved. In contrast, when the pH is about 3.5 or less, the tissue color becomes brown and does not return to its original color. Protein compositions having a "brown" colour are not suitable for addition to food products having a "raw" flesh colour. The present invention allows for the treatment of animal muscle tissue and the maintenance of the color of its original raw meat. It has also been found that the solubilization of animal muscle tissue results in a significant reduction of viable microorganisms (e.g., when food grade hydrochloric acid or sodium bicarbonate is used). In one embodiment, one food grade acid and base combination of interest in the present invention is citric acid to lower the pH and sodium bicarbonate to raise the pH. It has also been found that mixing fat with a food grade acid or base according to the invention stabilizes the fat against oxidation. Further, in one embodiment, it has been found that when acid containing fats are mixed with food grade alkali to a pH of about 4.9 to about 5.8, separation of water from the fats is achieved, reducing the water content from about 70 wt.% to about 50 wt.% to about 30 wt.% to about 20 wt.%. This result simplifies the subsequent removal of water from fat if such additional water removal is required.

Drawings

FIG. 1 is a process flow diagram of the method of the present invention for solubilizing a protein using an acid.

FIG. 2 is a process flow diagram of the method of the invention for solubilizing a protein using a base.

Detailed Description

The present invention relates to a process for treating animal offal to recover a meat product that retains its raw meat, functional color and low fat content, high in protein and essential amino acids, and a stable fat product. "meat product" describes a protein-containing product that is suitable for human consumption as meat because it contains a certain amount of protein. Generally, "deboned poultry meat" refers to fat and bone containing tissue isolated from poultry. "mechanically deboned poultry" means that it is separated during the slaughtering operation. Conventional poultry cuts or portions are typically sold directly to the consumer or further processed such as grinding into ground poultry meat. The tissue remaining after removal of the conventional cuts typically has a fat content that is too high for human consumption as meat, but contains protein that can be recovered.

According to the invention, once pieces of poultry meat containing bones, such as deboned poultry meat, have been removed from slaughtered animals (carcases), they are directly subjected to the method of the invention. Alternatively, the recovered poultry meat may be frozen or chilled and stored prior to processing. The temperature of the recovered poultry meat when it is removed from the slaughtered animal body is typically about 33-40F, which corresponds to the temperature at which the slaughtered animal body is stored prior to slaughter. Either hotter or colder heel can be used in the process of the invention.

The bone-containing poultry meat treated by the present invention may include all parts commonly found in animals, including adipose tissue, fat, lean ligaments, tendons, skeletal parts, and the like. It is generally desirable that components other than fat, lean meat and moisture, if present, be present in small amounts and/or be removable in a destinking step or manually if required, or be left in the poultry meat product if their presence does not adversely affect the properties thereof. If large amounts of certain components are present, they may need to be removed by conventional separation techniques prior to treatment according to the present invention. For example, it is often desirable that there be no significant amount of bone or a significant amount of low quality ligaments.

"Meat animal (Meat reducing animal 1 s)" includes animals known to provide Meat. Such animals include beef, pork, poultry such as chicken or turkey, e.g., deboned chicken, and the like. The lean material may be referred to as protein-containing material and may be in the form of water-soluble proteins, including muscle fibers, and water-insoluble proteins, typically myofibrils or motor proteins or connective tissue surrounding muscle fibers and attaching muscle fibers to ligaments. Of particular interest for the purposes of the present invention is the presence of water-soluble proteins and acid/base-soluble proteins from animal muscle tissue in the fat-containing tissue within the fat heel. By separating the proteinaceous material from the animal offal, a high quality meat product can be provided. The product can be used as an additive to conventional meat products such as meat patties (hamburgers).

The meat, fat and bone containing poultry meat useful in the present invention preferably has an average fat content of about 5 wt% to 50 wt% (e.g., 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% or 50 wt%), preferably about 10 to 30 wt%. The lean content of the bone-containing poultry meat is preferably about 65% to 85% by weight (e.g., 65%, 70%, 75%, 80%, or 85%), and more preferably about 75% to 85%. Lean content includes protein and moisture. In one embodiment, after undergoing the steps of the present invention, the resulting product is "fine-grained meat" (FTM) having a fat content of less than 30% by weight; a protein content of 14 wt% or more; the Protein Efficiency Ratio (PER) is 2.5 or more, or the content of Essential Amino Acids (EAA) is 33% or more of the total amino acids. In one embodiment, the present invention also results in "fine-grained lean meat" (LFTM) having a fat content of less than 10% by weight and meeting the other requirements for "fine-grained meat".

Referring to fig. 1 and 2, which illustrate an embodiment of the present invention, a feed 12, such as mechanically deboned or separated poultry meat having about 50 weight percent muscle tissue and about 50 weight percent fat, mechanically separated chicken, etc., is directed to a size reduction step 14, which increases the surface area of the poultry meat, making it more suitable for further processing. Suitable comminuting devices include meat minders available from Weiler and Company Corporation (located in Whitewater, WI) or Carnitec USA, Inc (located in Seattle, WA). The starting poultry meat is first ground to a size that can be placed through a micro-cutter. Preferably 3/4 inches, rough cut and then ground 1/8 inches. Some mechanically deboned meats may not require pre-grinding because they already have the proper particle size. Once ground, the material is mixed with water (33-40F.) in a ratio of one part ground meat to about 5-6 parts water. The amount of water can vary and can be up to about 1 part ground meat: 10 parts of cold water. The addition of water reduces the ionic strength of the homogenate required for complete solubilization of the protein. Optionally, an acid (fig. 1) or base (fig. 2) may be added to the poultry meat in step 20 to improve protein solubilization. The comminuted poultry meat is directed to a homogenization step 16 where it is mixed and homogenized with potable water 18, typically at a water temperature of about 33F to about 40F, typically to an average particle size of about 0.5 to about 4 mm, preferably about 1 to about 2 mm. It has been shown that a micro-cut with a cutting head size of 0.035mm is preferred. Representative suitable homogenizers for this purpose include an emulsifier (emulsifier) or a microtome available from Stephan Machinery Corporation (located in Columbus, OH), or a high shear mixer available from Silverson (located in East Longmeadow, MA), and the like.

During the step of controlling the microorganisms, the temperature of the homogenate is kept low (33-40 ℃ F.) throughout the process. Low temperatures are most effective for separating fat from protein. This unit operation is completed while the pH is still close to the pH of the original muscle. Another approach is to add sufficient food grade acid (fig. 1) or base (fig. 2) to bring the complex pH to the isoelectric point. Typically, the isoelectric point is about pH 5.5, but it may vary from species to species. At the isoelectric point, proteins are least likely to form an emulsion with lipid molecules, and thus more lipids are separated from proteins during extraction. Once the tissue is homogenized, it is ready to be adjusted to a low pH.

Referring to fig. 1, the resulting homogenate is directed to step 22 where it is mixed with a food-grade acid 24, such as dilute hydrochloric acid, dilute phosphoric acid, dilute citric acid, ascorbic acid, tartaric acid, or mixtures thereof, and the like, to lower the pH of the homogenate to pH3.6 to pH 4.4 (e.g., 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4), preferably pH3.6 to pH 3.8. In fig. 2, the homogenate in step 22 is mixed with a food grade base, such as sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, or sodium hydroxide, etc., to raise the pH to a pH in the range of about 8.3 to about 10.5 (e.g., about 8.4, 8.5, 8.6, 8.7, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4). The pH is lowered or raised to the above pH range to solubilize or solubilize animal muscle tissue to obtain a satisfactory yield of protein, such as 80% (85%, 90%, 95%, 96%, 97%, 98%, 99%, 100%) or higher in its solubilized protein solution, while maintaining the fat fraction in solid form. In one embodiment, hydrochloric acid is preferred because its use results in a more significant reduction of viable microorganisms in the acidic protein solution.

It has been shown that placing a protein in acid or base at low salt conditions can unfold the protein, which is believed to create more surface area along the protein and thus more potential water binding sites. It is believed that the base will make the protein charge negative (negative-negative repulsion), while the acid will make the protein charge positive-positive repulsion.

Once the protein is solubilized by the acid or base, the fat leaves the protein and floats to the surface of the aqueous solution. Other potential impurities, including any remaining bone, skin or muscle, also remain undissolved. The pH is adjusted to about 3.6 to 4.4 or about 8.3 to about 10.5. By way of example, the approximate amount of acid required to achieve solubilization of muscle protein is about 0.15 to 0.80 wt%, e.g., 0.198 wt%, based on the weight of HCl: total weight (pH 3.74). The amount depends on the desired low pH (pH 3.6 or 4.4) and the pH of the starting material. Similarly, for the base, sodium carbonate may be used at a concentration of about 0.7% to about 10% aqueous solution, and sodium bicarbonate may be used at a concentration of about 0.5% to about 10% aqueous solution (e.g., about 5% to 6%). Suitable mixers for this step include Lightning mixers (Lightning mixers) available from SPX Corporation (located in Charlotte, NC) and the like.

Solubility can be brought about by the addition of food grade acids or food grade bases. As used herein, "solubilized protein" refers to a protein that is dissolved in a liquid or placed in solution. In one embodiment, an acid or base is added in sufficient quantity and concentration to solubilize or solubilize the protein without denaturing the protein. Any food grade acid or base can be used to adjust the pH to the ranges described herein to solubilize the protein. Examples of food-grade acids useful in the present invention include citric acid, phosphoric acid, ascorbic acid, hydrochloric acid, or combinations thereof. Examples of food grade bases include sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, or sodium hydroxide. Other acids or bases, either previously known or later developed, may be used in the steps of the invention, provided they solubilize the protein under the conditions described herein and are food grade.

The volume and concentration of acid used to solubilize proteins at the desired pH will depend on the starting pH of the solution, as well as the volume of solution to achieve the appropriate pH. The concentration of the food grade acid will depend on the particular acid and composition (e.g., liquid or powder form) used, but ranges between about.5M to about 3M (e.g., between about 1M to about 2M) (molarity) or between.2% to about 90% w/w% (approximate strength). In the case of citric acid, a concentration of about 2M (e.g., about.5M to about 3M) can be used to solubilize the protein, and in the case of hydrochloric acid, a concentration of 1M (e.g., in the case of.2M to about 2M) can be used to solubilize the protein. For phosphoric acid, an intensity of 85% may be used. In the case of citric acid and phosphoric acid, about 0.3 wt% and about 1 wt% may be used, while for hydrochloric acid, a range of about 0.2 wt% to about 0.5 wt% may be used for the steps of the present invention. When ascorbic acid is used in the process of the invention, it may be used in its powder/crystalline form, in which case the ascorbic acid powder may be added directly to the homogenate. The food grade acid and its concentration should be selected so as not to denature the protein in the homogenate. In one embodiment, to solubilize the protein, the pH of the homogenate is adjusted by a food grade acid to obtain a resulting pH equal to or in the range of about 3.6 to about 4.2 (e.g., about 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, and 4.2).

In another embodiment, to solubilize the protein, the pH of the homogenate is adjusted with a food grade base to obtain a resulting pH equal to or in the range of about 8.3 to about 10.5 (e.g., about 8.4, 8.5, 8.6, 8.7, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4). The volume and concentration of base used at the desired pH will depend on the starting pH of the solution, as well as the volume at which the solution will reach the appropriate pH. The concentration of the food grade base will depend on the particular base and composition (e.g., liquid or powder form) used, but ranges between about.5M to about 3M (e.g., between about 1M to about 2M) (molarity) or between.2% to about 90% w/w% (approximate strength). In one embodiment, sodium carbonate may be used at a concentration of about 0.7% to about 10% aqueous solution, and sodium bicarbonate may be used at a concentration of about 0.5% to about 10% (e.g., about 5% to 6%) aqueous solution. Alternatively, when sodium bicarbonate is used, it may be added directly to the protein as a powder.

In one embodiment, solubilization of the homogenate refers to the protein being mostly dissolved or in solution. In another embodiment, solubilized means that the solution has at least about 75% (e.g., 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100%) solubilized protein. Once the protein is solubilized, it is referred to as a "solubilized liquid protein solution.

The resulting mixture of solubilized liquid protein solution and solid fat is then directed to a separation step 26, such as a decanter centrifuge and/or a screen filter 26, to separate the acidic protein solution from the solid fat.

After solubilization of the protein and removal of impurities and fat, the protein is precipitated by bringing the pH to or near the isoelectric point. In case of solubilization with acid, it may be solubilized by adding a food grade base such as sodium hydroxide (NaOH) or sodium bicarbonate (NaHCO)₃) To effect precipitation. In the case of using a base to solubilize the protein, precipitation may be accomplished by the addition of a food grade acid such as citric acid or the like. In one embodiment, when the pH reaches about 4.9 to about 6.4 (e.g., 4.9, 5).0. 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4). The isoelectric range may depend on, for example, conditions such as salt, type of protein, charge of the protein, amino acids making up the protein, and ionic strength of the solution in which the protein is placed. In one embodiment, a base or acid is added until the isoelectric point is obtained and/or the proteins refold and recombine with each other to form large, fibrotic molecules. When the isoelectric pH is reached, the protein releases its tightly packed water molecules and the moisture content can be restored to that found in meat or consistent with FTM or LFTM. Any food grade acid or base can be used to adjust the pH to these ranges, and examples and amounts of such acids and bases are provided herein in the solubilization discussion of step 22. The volume and concentration of acid or base used to achieve the desired pH will depend on the starting pH of the solution, as well as the volume of solution to achieve the appropriate pH. In another embodiment, precipitation refers to a suspension having at least about 75% (e.g., 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100%) protein precipitated.

Optionally, the solid fat in step 28 is mixed with a food grade base or acid to separate water from the fat and neutralize the fat. Optionally, cold drink water from step 29 may be added to the fat in step 28. The base or acid facilitates the separation of the fat from the water. The fat is then filtered in step 31 to remove water from the fat and reduce the water content from about 70 wt% to 50 wt% to about 30 wt% to 20 wt%. Optionally, the fat may be refrigerated or frozen in step 33. Suitable filtration devices include vibrating screens available from Sweco Corporation (located in Florence, KY) and the like. The size of the screen is between about 4000 microns to about 2000 microns, preferably between about 3500 microns to about 2500 microns.

Additional base or acid may be added in step 34 to restore the pH of the precipitated protein to the original pH of the tissue. This ensures that the base (e.g., NaOH or NaHCO)₃) Or the acid completely reacts with and consumes all of the previously added acid (e.g., HC1 or citric acid) or base, respectively. An optional step is to subject the protein to a treatmentThe product is directed to unit operation 35 which removes water to concentrate the liquid so as to produce larger fibers. The unit operation may consist of any device that removes water, such as an evaporator or ultrafiltration unit, in a continuous or batch manner. The amount of water removed can vary, however, greater amounts of water removed result in larger and stronger (robust) and strong (sturdy) fibers and higher protein recovery. The resulting protein product is a viscous precipitate containing protein at a concentration of about 4-14 wt.% or more to produce a protein-containing solution, which is directed to a mixing step 34 where it is mixed with a food grade base or acid 36. The protein product is precipitated in step 38 and recovered in step 40, such as by centrifugation and filtration. Optionally, recovered in step 41 has >5000-. The ultrafiltrate may be mixed with the protein precipitated in step 43 as desired. This results in a protein product with reduced sodium content. Sodium is concentrated in the lower molecular weight fraction which is discarded. The resulting product has reduced sodium and is obtained by a process that provides a high yield of protein of about 80% (85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%) or more from the starting poultry meat feed. Thus, the process of the present invention provides a protein product which is a substantial improvement over the prior art.

The protein product from step 40 contains 14 wt.% or more protein, contains less than 10 wt.% fat, is produced at temperatures below 110 ° f, can be frozen within 30 minutes from completion of the process in step 42, does not allow for a significant increase in bacteria, and in this embodiment, the precipitated protein retains no chemicals or additives other than low concentrations of salts (such as sodium chloride, etc.).

If a protein powder is desired, it may be decided to spray dry the dehydrated precipitate or the solubilized liquid protein solution. The precipitate or solubilized liquid protein solution can be spray dried to form a protein powder, which can be used as a protein powder or added to a food or beverage. Spray drying can be carried out using commercially available equipment, such as 30 inch Bowen Spray Dry g cell machine or GEA Niro Food Spray Dryer (

Denmark). A pretreatment step may be performed to prevent protein denaturation during spray drying and includes, for example, adding sodium bicarbonate or other base to the protein precipitate to bring the pH equal to or between about 6.5 and about 8.0.

The steps of the present invention include vacuum tumbling. Vacuum tumbling pulls the water evenly into the mixture. If vacuum tumbling is required, this can be done with the precipitate or solubilized liquid protein. The vacuum tumbling may last from about 20 minutes to about 90 minutes. In case a precipitate is used, water is added to the protein precipitate mixture. In the case of solubilized liquid protein, it is tumbled with meat chunks or animal muscle tissue to form cured meat products (e.g., cured chicken or beef). For example, a Vacuum roller such as a BIRO Manufacturing Model VTS-500Vacuum Tumbler may be used. The vacuum tumbling process pulls water into the mixture in a uniform manner. The vacuum tumbling step is optional. The obtained protein is protein marinade (marinade).

The treatment method of the present invention does not significantly alter the meat protein products of the present invention. Examination of the proteins associated with the starting meat source and the lean cold worked meat (precipitated refolded proteins) showed that the extraction process was sufficiently mild not to affect changes in the protein throughout the process. It also shows little or no hydrolysis occurring during the treatment, partly due to the low temperature. Protein refolding also does not affect its characteristics.

Unexpectedly, the method allows the protein product to substantially retain or retain its original color (as defined herein) and other functional properties. In other words, the protein subjected to the steps of the invention may in one aspect still retain its functional properties, including its original colour.

The resulting proteins have a number of characteristics. In another aspect, the product of the invention can meet the definition of "fine grain meat" (e.g., less than 30% fat content; 14% or more protein content) or "fine grain lean" (e.g., less than 10% fat content, 14% or more protein content), as currently defined by the U.S. government. In one embodiment, the protein product of the invention has about 14% or more (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25%) by weight protein and less than about 30% by weight (less than about 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0%) fat. In yet another aspect, the protein composition of the invention also has the functionality of raw meat as measured by a measurement selected from: water binding test, meat emulsion (eat emulsion) test, moisture retention test, color test/observation, and combinations thereof. In one aspect, the beef protein product of the invention has a color of 75-52L, 25-15a, and 23-16 b. For poultry meat, the raw meat color of the animal muscle tissue protein product is 82-45L, 7.5-2.2a, and 20-3 b.

Thus, the protein product may be used "as is", or may then be applied to raw meat which is sold to consumers without cooking. The method of the present invention results in a protein product as a functional meat composition. "functional" meat compositions function similarly to raw, uncooked meat. Functional meat is defined as a meat composition that behaves like raw meat with respect to one or more of the following characteristics: water binding, meat emulsion, moisture retention, and/or color. The present invention includes meat compositions that meet or exceed one or more of these functional meat characteristics.

Water binding capacity refers to the capacity of the protein product of the invention to retain and/or absorb Water and can be tested using the method of Hand et al, "A Technique to Measure the Water Up Properties of Meat," 77th annular Meeting of the American Society of Animal Science, Paper No.202 (1985). In short, water binding capacity can be determined by adding water to meat, shaking and centrifuging. After centrifugation, the centrifuged meat is placed on a wire screen and then weighed. The meat product subjected to the steps of the invention has the same or greater water binding capacity than meat not subjected to the steps of the invention. In one embodiment, the meat product subjected to the steps of the invention has the same or greater water binding capacity as compared to meat not subjected to the steps of the invention. In one embodiment, the water binding capacity of a meat product subjected to the steps of the present invention is from about 1% to about 125% (e.g., from about 40% to about 60% higher) greater than a meat not subjected to the steps of the present invention.

Meat emulsions, sometimes referred to as fat emulsions, generally refer to the ability of the proteins of the present invention to bind or adhere to themselves (e.g., their ability to adhere together) and/or to form a protein matrix (e.g., a viscous meat paste). In one example, the phrase "meat emulsion" refers to the binding capacity of protein, fat, water, and optionally other types of ingredients (e.g., butter, mayonnaise, dressings, etc.) that are typically added to such mixtures. Whether or not the emulsion is formed can be determined by observation. It can also be measured in terms of its capacity (e.g., maximum amount of fat or oil stabilized by a given amount of protein) or stability (amount of fat or oil remaining or separated after heating the meat emulsion/paste formed).

Moisture retention refers to the amount/level of moisture retained in the protein product at any given time. Moisture retention in meat products can be measured by using a moisture analyzer (e.g., Ohaus MB Model 25) or by observation (e.g., observing the amount of moisture dripping or escaping the meat). The meat product subjected to the inventive step has the same or greater moisture retention as compared to meat not subjected to the inventive step. In one aspect, a meat product subjected to the inventive steps has about the same or about 1% to about 5% higher (e.g., between about 2% to about 3% higher) moisture as compared to meat not subjected to the inventive steps. The moisture retention can be controlled during the dewatering step so that the moisture retention can be reduced to its original moisture content if desired.

The protein product of the present process produces a protein product that retains its original or most of its original raw meat color. The protein product of the present process produces a beef protein product having colors of about 75-52L, 25-15a, and 23-16b and a poultry protein product having colors of 82-45L, 7.5-2.2a, and 20-3 b. The method of the present invention allows the protein product to look and function like raw or functional meat. Based on XYZ coordinates, color is measured using the CIE L a b color system, where dimension L represents luminance and a and b represent color-opponent dimensions. L a b color space includes all perceptible colors. In practice, the colors are mapped using three-dimensional integers for color representation. The luminance L represents the darkest black and brightest white, while the a-axis represents the opposite colors red and green, and the b-axis represents yellow and blue. Color can be measured using a colorimeter or colorimeter (e.g., CR-10Plus from Konica Minolta (Ramsey, NJ, USA)). The steps of the present invention surprisingly produce a lean meat having all or most of its original raw meat color, or its color prior to processing. In one aspect, the red or raw meat color of the beef protein composition is defined as about 75 to 52L (e.g., 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52), about 25 to 15a (e.g., 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15), and about 23 to 16b (e.g., 23, 22, 21, 20, 19, 18, 17, 16). In one aspect, the raw meat color of the poultry meat protein composition is defined as about 82 to 45L (e.g., 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45), 7.5 to 2.2a (e.g., 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2) and about 20 to 3b (e.g., 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 6, 4, 3, 2.2, 2).

It has been surprisingly found that the appearance of the product of the present invention retains the physical appearance, including the color of uncooked raw beef or poultry meat to which the protein product is not added.

In summary, the process of the invention produces protein in higher yields than the prior art, contains fewer microorganisms than the prior art, and is in a form that is easier to mix with meat than the products of the prior art. Furthermore, the obtained fat product is rendered oxidation stable.

The following examples illustrate the invention and are not intended to limit the invention.

Example I

Frozen mechanically separated chicken was obtained from Georgia's commercial production facility. The product was completely thawed at refrigeration temperature and the thawed meat was mixed with cold water at a ratio of 1: 4 (meat: water) are mixed. The mixture was homogenized for 2min at high speed using a Kitchen Aid hand mixer. The homogenate was adjusted to pH 2.8 or 3.6 using hydrochloric acid (2N). The acidified homogenate was filtered through a 1000 micron stainless steel screen. The filtrate was adjusted to pH 5.5 using sodium hydroxide (4N) and filtered through the same washed 1000 micron sieve to remove water. The precipitated samples were frozen and sent to Silaker Labs (Chicago Heights, IL) for analysis.

Table 1 metals and oxidation numbers of precipitated Lean Cold worked Chicken (bean Cold Processed Chicken) at pH 2.8 and pH 3.6

The treatment of mechanically separated poultry meat by the present invention shows lower sodium and calcium compared to the starting material and overall reduces the amount of oxidation occurring in the final product. Treatment to pH 3.6 results in a substantial reduction in metals compared to pH 2.8 and further reduces the amount of oxidation that has occurred. It can be found in the literature that oxidation is accelerated at low acidic pH values, and therefore it can be explained in this experiment that oxidation increases when meat is treated at lower pH values.

Example 2

This example illustrates that protein recovery from meat trim must be carried out at a pH of 3.6 or higher in order to recover the protein product in a satisfactory color. This example also illustrates that the initially obtained protein with an unsatisfactory color cannot be reversibly converted to a protein product with a satisfactory color.

The results obtained in table 2 were obtained with 40g samples of ground beef. 160ml of cold tap water (40F.) was added to each sample. The sample was then homogenized to a particle size of about 100 microns. The pH of each sample was adjusted to the pH listed in table 2 with 1M food grade hydrochloric acid. Each sample was centrifuged at 5000g for 8 minutes at 4 ℃ and then filtered through glass wool to separate the solid fat from the protein liquid composition. 40ml of each liquid portion was poured into a container on top of a white paper. Each sample was then measured twice with a Minolta colorimeter, measuring L, a and b values as described above.

Then the average L, a and b are calculated as shown in table 2.

TABLE 2 color measurement of ground beef

Example 3 experiment: color as a function of pH

The purpose is as follows: the redness values (L, a, b a of the system) at low pH when extracting protein from turkey and chicken legs were studied.

Materials: turkey proteins were extracted from P1ainville Farms pure natural turkey patties (burgers), and chicken proteins were extracted from Springer Mountain Farms boneless, skinless chicken leg meat (freshly obtained from the local market).

The method comprises the following steps: the turkey meat and chicken leg meat were separately ground and placed in cold spring water at a level of 5.68% (w/w). The mixture was homogenized for 1.5 minutes using a hand held kitchen stick mixer (Hamilton Beach). The homogenate was then adjusted to different low pH values using crystalline citric acid. At the selected pH, "a-value" was measured using a hand-held colorimeter (precision Color Reader-TO21, China; D65; 10;. SCI; 8mm) which was placed in position TO view the liquid through clear glass. Color values are the average of triplicate readings.

As a result:

table 1 redness "a values" at different pH values of acidified, homogenized poultry meat.

And (4) conclusion: as seen in beef, the a value changes as the pH changes from pH 3.6 to pH 3.5. The amount of citric acid (turkey) required to adjust the pH to 3.6 was 1.67g, which was 1.76g when the pH was adjusted to 3.5. For chicken leg meat, 1.58g was required to adjust to pH 3.6, and 1.64g was required to adjust to pH 3.5. Using the L, a, b value system, the a value follows a color change from green (low value) to red (high value). Thus, the higher the value of a, the more "red" the color of the article will be. According to our experiments, a visual transition from "reddish" to "brownish" occurs as the pH changes from 3.6 to 3.5.

This data demonstrates that a "brown" protein composition is produced at a pH range of 3.5 and below. Samples in the claimed pH range of 3.6 to 4.4 and the preferred range of 3.6 to 4.0 produced protein compositions with a raw meat color, redder. The color of poultry meat treated at a pH of 3.6 to 4.0 produces protein that retains its "reddish" raw meat color, which is substantially the same as its original color prior to processing. a decreases significantly from pH 3.6 to pH 3.5, indicating a color shift from redder to near brown. As the a value becomes more positive, the color is more perceived as red. At pH values of 3.6 and 3.5, turkey a values were 2.21 and 1.47, respectively, and chicken a values were 3.87 and 2.13, respectively. This is a significant difference corresponding to solutions at those pH values and establishes a clear boundary between "red" and "brown".

The terms comprises, includes, and/or each plural is open-ended and includes the listed items and may include additional items not listed. The phrase "and/or" is open-ended and includes one or more of the listed items as well as combinations of the listed items.

The relevant teachings of all references, patents, and/or patent applications cited herein are incorporated by reference in their entirety.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.

Claims (19)

1. A process for recovering a protein composition from deboned poultry meat containing fat, bone and protein and initial levels of calcium and sodium, the protein composition having a color of 82-45L, 7.5-2.2a and 20-3b and having reduced levels of calcium and sodium as compared to the initial levels of calcium and sodium, wherein the deboned poultry meat has 65-85% by weight of lean meat protein, the process comprising the steps of:

A) comminuting the poultry meat in water to obtain comminuted poultry meat,

B) adjusting the pH of the comminuted poultry meat of step A) to solubilize the protein to obtain a solubilized liquid protein solution, wherein the pH adjustment for solubilizing protein comprises adding a food grade base to obtain a pH value in the range of about 8.3 to about 10.5, thereby obtaining a solubilized liquid protein solution in which calcium remains insoluble,

C) Separating solid fat from solubilized proteins from the solubilized liquid protein solution of step B), wherein calcium is separated from the solubilized proteins together with the solid fat, thereby obtaining a fat-reduced solubilized liquid protein solution,

D) precipitating proteins in the reduced fat solubilized liquid protein solution of step C) to obtain precipitated proteins, wherein sodium remains soluble and produces a protein composition having a color of 82-45L, 7.5-2.2a, and 20-3 b;

wherein the protein composition has reduced levels of calcium and sodium as compared to initial levels of calcium and sodium, and the protein composition has 14 wt.% or more protein and less than 30 wt.% fat, wherein the less than 30 wt.% fat is stable to oxidation.

2. The method of claim 1, the protein composition having 14 wt.% or more protein and less than 10 wt.% fat.

3. The method of claim 1, wherein step a) and step B) are performed simultaneously.

4. The method of claim 1, wherein precipitating the protein from the solubilized liquid protein solution comprises bringing the pH to a value in the range of about 4.9 to about 6.4.

5. The method of claim 4, wherein the step of precipitating the protein of step D) comprises adding an acid to lower the pH to a value in the range of about 4.9 to about 6.4.

6. The method of claim 1, wherein adding a food grade base in step B) comprises adding a food grade base selected from the group consisting of: sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, sodium hydroxide, and any combination thereof.

7. The method of claim 5, wherein the step of precipitating the protein of step D) comprises adding a food grade acid selected from the group consisting of: citric acid, phosphoric acid, ascorbic acid, hydrochloric acid, and any combination thereof.

8. The method of claim 1, evaluating the functionality of the precipitated protein.

9. The method of claim 8, wherein the functionality of the precipitated protein of step D) is determined by a measurement selected from the group consisting of: a water binding test, a meat emulsion test, a moisture retention test, a color test, and combinations thereof.

10. The method of claim 1, further comprising spray drying the precipitated protein.

11. The method of claim 10, further comprising adding a second base to the precipitated protein such that the pH ranges between about 6.5 to about 8.0, and then spray drying the precipitated protein.

12. The method of claim 1, further comprising vacuum tumbling the precipitated protein.

13. The method of claim 1, wherein the deboned poultry meat is mechanically deboned poultry meat.

14. A process for recovering a protein composition from deboned poultry meat containing fat, bone and protein and initial levels of calcium and sodium, said protein composition having a color of 82-45L, 7.5-2.2a and 20-3b, wherein said deboned poultry meat has 65-85% by weight of lean meat protein, said process comprising the steps of:

A) comminuting the poultry meat in water to obtain comminuted poultry meat,

B) adjusting the pH of the comminuted poultry meat of step A) to solubilize the protein to obtain a solubilized liquid protein solution, wherein the pH adjustment for solubilizing protein comprises adding a food grade base to obtain a pH value in the range of about 8.3 to about 10.5, thereby obtaining a solubilized liquid protein solution,

C) separating solid fat from the solubilized protein from the solubilized liquid protein solution of step B), thereby obtaining a solubilized liquid protein solution,

D) precipitating the proteins in the solubilized liquid protein solution of step C) to obtain precipitated proteins, thereby obtaining a protein composition having colors of 82-45L, 7.5-2.2a, and 20-3 b;

Wherein the protein composition has 14 wt.% or more protein and less than 30 wt.% fat.

15. The process of claim 14, wherein in step B) the calcium remains insoluble and in step C) the calcium is separated from the solubilized protein together with the solid fat.

16. The method of claim 15, wherein the protein composition has reduced levels of calcium and sodium as compared to initial levels of calcium and sodium, and the protein and fat are stable to oxidation.

17. A protein composition obtained from deboned poultry meat containing fat, bone and protein and initial levels of calcium and sodium, wherein the protein composition has a color of 82-45L, 7.5-2.2a, and 20-3b, and the protein composition has reduced levels of calcium and sodium as compared to the initial levels of calcium and sodium, wherein the deboned poultry meat has 65-85 wt% lean protein, the protein composition obtained by a process comprising the steps of:

A) comminuting the poultry meat in water to obtain comminuted poultry meat,

B) adjusting the pH of the comminuted poultry meat of step A) to solubilize the protein to obtain a solubilized liquid protein solution, wherein the pH adjustment for solubilizing protein comprises adding a food grade base to obtain a pH value in the range of about 8.3 to about 10.5, thereby obtaining a solubilized liquid protein solution in which calcium remains insoluble,

C) Separating solid fat from solubilized proteins from the solubilized liquid protein solution of step B), wherein calcium is separated from solubilized proteins together with the solid fat, thereby obtaining a fat-reduced solubilized liquid protein solution,

D) precipitating proteins in the reduced fat solubilized liquid protein solution of step C) to obtain precipitated proteins, wherein sodium remains soluble and produces a protein composition having a color of 82-45L, 7.5-2.2a, and 20-3 b;

wherein the protein composition has reduced levels of calcium and sodium as compared to initial levels of calcium and sodium, and the protein composition has 14 wt.% or more protein and less than 30 wt.% fat, wherein the less than 30 wt.% fat is stable to oxidation.

18. The protein composition of claim 17 having 14 wt.% or more protein and less than 10 wt.% fat.

19. A protein composition obtained from deboned poultry meat containing fat, bone and protein and initial levels of calcium and sodium, wherein the protein composition has a color of 82-45L, 7.5-2.2a and 20-3b, and the deboned poultry meat has 65-85% by weight of lean meat protein, the protein composition obtained from a process comprising the steps of:

A) Comminuting the poultry meat in water to obtain comminuted poultry meat,

B) adjusting the pH of the comminuted poultry meat of step A) to solubilize the protein to obtain a solubilized liquid protein solution, wherein the pH adjustment for solubilizing protein comprises adding a food grade base to obtain a pH value in the range of about 8.3 to about 10.5, thereby obtaining a solubilized liquid protein solution,

C) separating solid fat from the solubilized protein from the solubilized liquid protein solution of step B), thereby obtaining a solubilized liquid protein solution,

D) precipitating the proteins in the solubilized liquid protein solution of step C) to obtain precipitated proteins, thereby obtaining a protein composition having colors of 82-45L, 7.5-2.2a, and 20-3 b;

wherein the protein composition has 14 wt.% or more protein and less than 30 wt.% fat.

Images