BACKGROUND OF THE INVENTION

Over a number of years research has been directed to the isolation of proteins from animal muscle tissue and the application of such isolated proteins to various foods to achieve improved functionality in comparison with foods cooked without such proteins. For example, when certain of these prior art proteins have been sprayed onto food to be cooked by frying, the cooked food has a reduced fat content over food that does not include such protein. In other applications, food cooked with the addition of such prior art protein, as by injection, retains more moisture than untreated cooked food.

Food safety is an important concern in today's modern food processing plants and methods are often being sought after to reduce overall bacteria or pathogen counts. For some foods, pasteurization is selected as a food preservation method; in others, sterilization. In many countries, such as Australia, the importation of meat products into a country requires that the meat products be either pasteurized or sterilized before such products can be imported to that country.

When harvesting has been completed, some animal muscle tissue remains attached to bones. Such attached animal muscle tissue is a potentially commercially viable animal muscle tissue for obtaining protein. “Deboning” is a process for recovering such residual animal muscle tissue from the bones. During deboning animal muscle tissue is separated from a bone by scraping, shaving or pressing the attached animal muscle tissue from the bone. Deboned product is called “deboned meat” or “separated meat.” While such a process theoretically could provide an economical source of animal muscle tissue for the isolation of protein, commercial deboning commonly tests high in bacteria and/or positive in food-borne pathogens, including salmonella. Due to the inherent risk of these bacteria many food processors require any product including mechanically deboned meat or even protein obtained from mechanically deboned meat be fully cooked for human consumption for health reasons and not sold in a raw state. Specifically, a food processing company must heat a “ready-to-eat” product to an internal temperature of at least 160° F. to achieve a lethality in the range of 6.5-log10to 7.0-log10. This requirement limits the applications for mechanically deboned meat primarily by imposing significant manufacturing costs and by producing a meat product that is “well done” and that loses moisture during cooking.

A need exists for a procedure that could assure pasteurization or sterilization of meat products without reducing the meat's functionality. Also, a further need exists for a procedure that could utilize a starting material that is potentially inherently high in pathogens, such as deboned meat. Yet, a further need exists for a food preparation method for obtaining protein from animal meat or mechanically deboned meat whereby the protein product can be consumed alone or added to raw meat such that the final product meets or exceeds the government and commercial standards for bacteria and toxic content without cooking the raw meat and that retains moisture prior to a consumer's cooking the final product.

SUMMARY OF THE INVENTION

This invention generally relates to protein compositions derived from animal muscle tissue for incorporation into raw food and more specifically provides a protein composition with a reduced risk of being contaminated by various microorganisms.

Therefore, it is an object of this invention to provide a process by which a protein product can be obtained from animal muscle or mechanically deboned meat that can be consumed alone or added to meat so that a final product meets or exceeds government and commercial regulations and a corresponding protein product.

Another object of this invention is to provide a process by which a protein product obtained from animal muscle tissue or deboned (e.g., mechanically deboned) meat can be added to raw meat to obtain a final product without cooking the final product and corresponding protein product.

Still another object of this invention is to provide a protein product obtained from animal muscle tissue or mechanically deboned meat that can be added to raw meat without cooking while retaining the functionality of the raw meat.

In accordance with one aspect this invention a process for producing a pasteurized or sterilized protein product from animal muscle tissue obtained from raw meat or mechanically deboned meat for application to raw meat includes homogenizing the animal muscle tissue from the raw meat or mechanically deboned animal muscle tissue (optionally in water). After adjusting the pH of the homogenate to solubilize the protein, the process elevates temperature of the homogenate to an internal temperature required for pasteurization or sterilization for at least a required time. The homogenate is then optionally chilled to an intermediate temperature whereupon the protein is optionally precipitated from the homogenate. The moisture content can then be adjusted to a desired value. As the protein product has been pasteurized or sterilized, there is no need for cooking a meat product containing the protein product, and such a protein product would meet or exceed bacterial standards established by an importing country.

In accordance with another aspect of this invention, a process for producing a pasteurized or sterilized protein product from animal muscle tissue obtained from animal meat for application to raw meat is obtained by mixing and homogenizing the animal muscle tissue and water. In an embodiment, homogenizing the animal muscle tissue can be done without the addition of water. After adjusting the pH of the homogenate to solubilize the protein, the process elevates the temperature of the pH adjusted homogenate to an internal temperature required for pasteurization or sterilization. The homogenate is then optionally chilled to an intermediate temperature. Depending on the protein product use, in some embodiments, the protein can be precipitated from the chilled homogenate by adjusting the pH of the homogenate into the isoelectric range. Then the process dewaters the protein to a desired moisture content.

The present invention includes protein produce and a method or process for producing a protein product wherein the protein product has a reduced pathogen level, retains a functionality of raw meat and has a color in range between about 75 to 20 L* about 32 to 4 a*, and about 23 to 3 b*. The steps of the method include homogenizing the animal muscle tissue, optionally in water, to thereby obtain a homogenate and adjusting the pH of the homogenate to solubilize the protein to obtain a solubilized liquid protein solution. The pH adjustment for solubilizing the protein includes the addition of a food grade base to obtain a pH value in the range between about 8.3 and about 10.5, or in another embodiment includes addition of a food grade acid to obtain a pH value in the range between about 3.6 and about 4.2. The solubilized liquid protein solution is then pasteurized or sterilized. Specifically, this step includes elevating the temperature of the solubilized liquid protein solution to an internal temperature of 158° F. or above for at least an instant, or to an internal temperature of about 130° F. and about 157° F. for at least between about 14 seconds to about 121 minutes such that the solubilized liquid protein solution is pasteurized, sterilized or both to obtain a solubilized liquid protein solution with a reduced pathogen level (e.g., wherein the reduced pathogen level comprises at least a reduction in salmonella by 6.5 log10). The method of the present invention further involves optionally chilling the solubilized liquid protein solution with the reduced pathogen level to an intermediate temperature to obtain a chilled liquid protein solution. In an embodiment, the liquid protein solution is precipitated to thereby obtain a precipitated protein. The method/process results in a precipitated protein has reduced pathogen level as compared to a precipitated protein that has not undergone the steps of the present invention. The precipitated protein also retains the functionality of raw meat and has “red” color in range between about 75 to 20 L*, about 32 to 4 a*, and about 23 to 3 b*.

In an aspect, precipitating the protein from the chilled liquid protein solution includes the adding a food grade acid or base to obtain a pH at or near the isoelectric point, or a pH to a value in the range of 4.2≤pH≤6.4. In another aspect, precipitating the protein from the chilled liquid protein solution encompasses adding salt. Food grade base used in either the solubilization step or precipitation step, for example, includes solution sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, sodium hydroxide any combination thereof. Similarly, food grade acid used in either the solubilization step or precipitation step encompasses, e.g., citric acid, phosphoric acid, ascorbic acid, hydrochloric acid and any combination thereof.

The method of the present invention can further include, in an embodiment, the step of assessing the functionality of the precipitated protein. Protein having a “red” color, as described herein, is a characteristic of raw meat and is considered to be functional. Functionality can be measured using a water binding test, meat emulsion test, moisture retention test, a color test (e.g., can be observed or color values can be measured) and a combination thereof. The process of the present invention can further include dewatering the precipitate, in an embodiment, to a desired moisture content.

As described above, the present invention includes a protein product and methods with the steps described herein, but the precipitation step, in one embodiment, is optional. In the case in which the precipitation step is not preformed, the solubilized liquid protein solution is the protein product, as is, or modified as desired. In such an embodiment, adding the solubilized liquid protein solution with the reduced pathogen level to the animal muscle tissue refers to injecting the solubilized liquid protein solution with the reduced pathogen level into the animal muscle tissue. Alternatively, the solubilized liquid protein solution with the reduced pathogen level can be sprayed or applied onto one or more surfaces of the animal muscle tissue. In other embodiments, the solubilized liquid protein solution can be dewatered to a desired moisture content or spray-dried.

