Method for reducing protein exudate on meat product

#The invention relates to a method for processing meat and, in particular, to a method of processing meat that eliminates visible protein exudate formation on the meat and meat products.

#In commercial systems for making certain processed meat products such as bologna and hot dogs, raw meat in the form of chunks or pieces and other ingredients such as spices are ground, chopped and/or otherwise blended with one or more salt solutions or brine to provide a mixture that can subsequently be formed into a stable meat emulsion or protein matrix. Similar steps of grinding, chopping and/or otherwise working are also employed in making coarse ground products such as sausages, whole muscle products such as processed ham and processed turkey, and other processed meat products. In each case, protein forms a matrix to hold or bond the separate pieces together.

#A stable protein matrix requires the protein bonds to suspend or bond with fat and water. Creation of protein bonds in this context requires a process commonly known as protein extraction. In this process, salt soluble or salt-extractable and heat coagulable proteins such as myosin, actomyosin, and actin bind water, swell and become tacky as a result of working or blending of the meat in the presence of a salt or a salt solution. The proteins are subsequently set when heated to create a bond. Other myofibrillar proteins, as well as sarcoplasmic or water soluble or extractable proteins, may also play a role in bonding. Salt solutions that may be used in protein extraction include, but are not limited to, sodium chloride, sodium pyrophosphate or diphosphate, potassium chloride, sodium lactate, and potassium lactate. In protein extraction as described herein, the mechanism believed to be primarily responsible for creation of the bonds involves binding proteins, salts, fats, and/or water and subsequent swelling of the proteins, rather than solution of the proteins. More precisely, it is believed that the salt solution frees bonding sites on the proteins for bonding with each other, as well as with water and fat. The particles of the cooked product are bound to each other by the proteins to provide integrity to the final meat product.

#FIG. 1 is a schematic representation of a continuous mixing processor in accordance with an embodiment of the invention;

#FIG. 2 is a perspective view of a mixing apparatus used in an embodiment of the invention, shown with a portion of the housing removed;

#FIG. 3 is a front elevation view of a component of the apparatus of FIG. 2;

#Referring initially to FIG. 1, apparatus for making processed meat products in accordance with an embodiment of the invention is shown diagrammatically at 10. The illustrated apparatus comprises a motor 12 and a belt drive 14 transmitting power to one or more mixing devices 16 located in a housing 20. Ingredients such as chunks or pieces of meat, one or more salt solutions, water, flavorings such as spices, and preservatives are input through input lines, including pumps 84, directly into the housing 20. The input line pumps 84 and mixing devices advance the mixture through the housing while the mixing device applies a high shear rate to the mixture to achieve rapid protein extraction from the meat components. The mixing devices are preferably made of stainless steel or another material that is wear resistant and suitable for contact with food product components.

#While a single elongated screw as shown in FIG. 1 may be employed as a mixing device in some embodiments, other embodiments employ other types of mixing devices. The embodiment illustrated in FIG. 2 employs a twin shaft arrangement with a relatively short infeed screw 17 used in combination with a longer array of mixing elements 18 on each shaft 19. As the ingredients are forced through the housing 20, the rotating mixing elements 18 macerate and/or mix the ingredients, and subject the ingredients to high shear force by driving them between the mixing elements 18, and between the mixing elements 18 and interior walls of the housing 20. The minimum gaps or clearances between the mixing elements 18 of one shaft 19 and the mixing elements of a second mixing device 16, as well as between the mixing elements 18 and the housing 20, are preferably between 0.06 in. and 0.12 in. In some embodiments, the gaps are 0.08 in. As the shafts rotate, the distance between mixing elements 18 on respective shafts will vary so that, for instance, whole muscle portions may be forced through without being chopped or ground. Forcing the mixture through these gaps applies high shear force and results in rapid protein extraction.

#The meat, water, salt solution and other additives such as a spice slurry are simultaneously fed into the mixing device. Protein extraction herein involves an intimate contact between the salt solution and the salt-extractable proteins and breaking of the meat structure to separate protein strands, breaking the protein strands themselves, or unraveling of the proteins. The mixing device applying the high shear force mechanically provides this intimate contact, as opposed to the diffusion utilized in typical batch processes.