Texturized soy protein

Protein-Based Substitutes. Several plant and animal-based proteins have been used in processed meat products to increase yields, reduce reformulation costs, enhance specific functional properties, and decrease fat content. Examples of these protein additives are wheat flour, wheat gluten, soy flour, soy protein concentrate, soy protein isolate, textured soy protein, cottonseed flour, oat flour, com germ meal, nonfat dry milk, caseinates, whey proteins, surimi, blood plasma, and egg proteins. Most of these protein ingredients can be included in cooked sausages with a maximum level allowed up to 3.5% of the formulation, except soy protein isolate and caseinates are restricted to 2% (44). 

Textured Soy Proteins. Textured vegetable proteins, primarily textured flours and concentrates (50% protein and 70% protein, dry basis, respectfully) are widely used in the processed meat industry to provide meat-like structure and reduce ingredient costs (3-6, 9-10). Available in a variety of sizes, shapes, colored or uncolored, flavored or unflavored, fortified or unfortified, textured soy proteins can resemble any basic meat ingredient. Beef, pork, seafood and poultry applications are possible 03, 4-7, 15, 19) Proper protein selection and hydration is critical to achieving superior finished product quality. Textured proteins have virtually no solubility and, thus, no ability to penetrate into whole muscle tissue Therefore, textured soy proteins are inherently restricted to coarse ground (e.g. sausage) or fine emulsion (e.g. weiners and bologna) products, and comminuted and reformed (i.e. restructured) meat products. None are used in whole muscle absorption or injection applications (2-4, 6, 11). 

Soy Protein Concentrates. Both non-functional (low or no solubility) and functional (good solubility, emulsification capacity, and dispersibility) soy protein concentrates (70% protein, dry basis) are commercially available for use in meat products (2-4, 6, j), 15) Normally, a highly functional product with no harsh or bitter flavors is desirable. When used to replace lean meat, non-hydrated concentrate can be used at levels up to 6-7% in finished nonspecific emulsion meats Higher replacement levels or formulas with specific cost/nutrition requirements may use soy protein concentrate with a judicious amount of textured soy protein (6). Excellent yields, cost savings, texture, flavor and nutrient profiles are possible. However, most soy protein concentrates lack sufficient solubility or sufficiently low viscosities to be used in brines for absorption or injection into whole muscle tissue. When legal standards for protein content exist (13), more concentrate must be used to achieve legal minimums. Brine viscosities increase and uniform distribution of brine components throughout the specific whole muscle piece is restricted. Finished product appearance and flavor are easily compromised. Thus, use of soy protein concentrates in whole muscle applications is limited. 

Textured soy protein products in their use as meat alternatives have become increasingly popular in school lunch programs since their introduction in 1971. A sov-modified macaroni was introduced into the family food assistance program a number of years ago. 

When texturized soy protein was used to replace some of the meat in patties, undesirable off-flavors were released during preparation and consumption of the meat-soy mix (3). The source of these were identified as oxidation products of unsaturated fatty acids. High protein content soy ingredients have mitigated this problem (4j. 

There was no loss in flavorant at a 100 mg level when either whole soy or soy 7S protein was used, but there was a 14-24 percentage loss when 11S protein was used. Only soy 11S protein affected the substituted pyrazine content of the mixture at all addition levels. The higher the substituted pyrazine congener, the smaller was the percentage loss with any of the protein types. At the 500 mg level, only about 50% of the amount of any of the methyl pyrazines in the control was recovered from either soy 7S or 11S protein while 70% was recovered from whole soy protein. These results greatly extend the initial work reported by Palkert and Fagerson (11J who determined that about 75% of dimethyl thiazole, a sulfur-nitrogen heterocycle, was recovered from dry, textured soy protein. 

Although the role of zinc in human subjects has been now defined and its deficiency recognized in several clinical conditions, these examples are not representative of a pure zinc deficient state in man. It was, therefore, considered desirable to develop a human model which would allow a study of the effects of a mild zinc deficient state in man. Recently such a model has been established successfully in human volunteers with the use of a semi-purified diet based on texturized soy protein. 

The texturized soy protein and soy protein isolate were washed twice with ethylenedlamlnetetraacetate, then rinsed three times with deionized water, boiled for 30 min. and kept frozen until ready to be used. Most recipes used in this study were adapted from Soy Protein Recipe Ideas, published by Institution Volume Feeding Management Magazine, Chicago, Illinois. 

Both the textured soy protein and oil products retain natural antioxidants and have good shelf life. 

A semipurified diet based on textured soy protein purchased from General Mills Co., Minneapolis, Minn. (Bontrae Products) and Worthington Foods Co., Division of Miles Laboratory, Elkart, Indiana, was developed for this study. Soy protein isolate, which was used as soy flour in the baked goods, was purchased from General Biochemicals (Teklad Mills, Chagrin Falls, Ohio). The texturized soy meals used were hamburger granules, chicken slices, turkey slices, and chicken chunks. The texturized soy protein and soy protein isolate were washed twice with ethylenediaminetetraacetate (EDTA), then rinsed three times with deionized water, boiled for 30 minutes, and kept frozen until ready to be... 

Textured Procon. [Central Soya] Textured soy protein cone. 

The first soybean protein ingredients made commercially available for food use included full-fat and defatted soy flours and grits (3, 7, 8). These products contain ca. 46-59% protein (NX 6.25) on a moisture-free basis and are available with various heat treatments for specific end-use. Soy protein concentrates and soy protein isolates were introduced into the market about 15 years ago (3, 9, 10, II). By definition soy protein concentrates must contain no less than 70% protein (N X 6.25) and isolates no less than 90% protein (N X 6.25), all on a moisure-free basis. In the past several years there has been much activity in the commercialization of textured soy protein products intended for the extension and replacement of meat. These textured products may be obtained through fiber spinning, shred formation, extrusion, or compaction (12, 13, 14, 15). In addition, soybean milk solids and the heterogeneous proteins in soybean whey might serve as useful substrates in chemical modifications for food use. This short recitation of commercial products illustrates the type of crude protein fractions available for practical modification. Many useful functional properties have been ascribed to these new food proteins. 

Data from Clapper et al. (2001). SBM = soybean meal SPCl = soy protein concentrate (traditional aqueous alcohol-extracted SPC) SPC2 = texturized soy protein (extruded SPC) SPC3 = modified molecular weight SPC (low antigen product). 

The principles of extrusion were described by Mercier et al. (1989) and. the processing of proteins by Stanley (1989) and Rokey et al. (1993). Texturized Vegetable Protein and TVP are registered trademarks of the Archer Daniels Midland Company, Decatur, Illinois, and the generic terms texturized soy protein, TSP, or texturized vegetable foodprotein are used. Two types of products are made (i) extrusion-cooked meat extenders, which are made from SF or flakes or SPC and are rehydrated to 60 to 65% moisture before blending with meats or meat emulsions at levels of 20 to 30% and... 

Fig. 19.26. Process diagram for preparing texturized soy protein (Source provided by Wenger Manufacturing Company, Sebetha, KS).

Product Soy Protein Isolate Soy Protein Concentrate Soy Flour or Grits Textured Soy Protein... 

Heywood, A.A. D.J. Myers T.B. Bailey L.A. Johnson. Effect of value-enhanced texturized soy protein on the sensory and cooking properties of beef patties./. Am. Oil Chem. Soc. 2002b, 79, 703-707. 

Riaz, M.N. Extrusion-expelling of soybeans for texturized soy protein. Proceedings of the World Conference on Oilseed Processing and Utilization R. Wilson, Ed. AOCS Press Champaign, IL, 2001 pp. 171-175. 

Soy-based products that are not fermented (soy milk, tofu, textured soy protein, hydrolyzed vegetable protein, soy protein concentrate, meat analogs, unfermented soy sauce )... 

Palkert. P.E. Fagerson, I.S. Determination of flavor retention in pre-extmsion flavored textured soy protein. J. Food Sci. 1980, 45, 526-533. 

Texturized soy protein Baby formula (soy protein) Simulated bacon soy protein) Corn chips... 

Different nutritional needs prevail in industrialized economies. For the affluent, meat analogs made from textured soy protein are largely free of cholesterol and high in polyunsaturates. For example, one kind of sausage made from textured soy protein contains 40% more polyunsaturated fats than saturated fats, while traditional pork sausage contains 400% more saturated than polyunsaturated fats. ... 

Soy protein is available to the food industry in a multitude of forms, most of which may be classified according to protein content as (1) soy flour and grits, containing 40 to 50% protein (2) soy protein concentrates, with about 70% protein (3) soy protein isolates, with 90 to 95% protein and (4) textured soy protein, which is made from one or more of the other three types. Fig. S-26 shows an attractive meat-substitute dish. 

Soy Protein Isolates, Concentrates, and Textured Soy Protein Products, Soyfoods Center, Lafayette, LA. 

---