Soybean meal product qualities

Quality standards and trading rules for solvent-extracted soybean meal and oil are designated by the National Oilseed Processors Association and are available at a website (145). Soybean products are remarkably uniform in their quality characteristics compared with alternative sources of oil and meal. 

Laboratory tests such as urease activity, protein dispersibility index (PDI), nitrogen solubility index (NSI), thiamine, and water absorption have been found valuable in monitoring daily production for protein quality. But biological chick and/or rat assays are the only reliable means currently available for predetermining the nutritional value of whole soybean protein they must be conducted periodically to verify results of chemical tests (31). If whole soybeans are to be used in a mixture containing 20% or more soybean meal, 5% or more urea, and 20% or more molasses, or an equivalent mixture, and exposed to hot, humid storage conditions, it is advisable that the urease activity of the whole soybeans not exceed 0.12 increase in pH (31). Extruded or roasted soybeans properly treated for cattle to increase bypass protein should have urease values of less than 0.05 pH rise. A urease rise of 0.05-0.20 is an indication of proper treatment for swine and poultry. 

Edible Products Derived from Soybean Meal. The primary edible products derived from soybean meal/flakes are flour/grits (at 50% protein), protein concentrates (containing 65-70% or more of protein) and protein isolates (90% protein). The nutritional quality, availability, price, and functionahty of these products has resulted in substantial usage in a wide variety of food and feed products. Given current trends in food consumption, strong growth in the use of soy protein products in foods appears assured (8, 9). A number of excellent articles on the manufacture of soy protein products exist processing will not be described in detail here (8, 10-13). 

To process soybeans into these useful products, the beans are dehulled and the oil is removed by crushing at very high pressure or by solvent extraction. If the resulting dry soybean meal is intended for food, it is heated to 70°C or higher to coagulate the proteins and caramelize the carbohydrates, thus improving their nutritional qualities. If the soybean meal is intended for adhesive use, it is processed at temperatures below 70°C to preserve the alkaline solubility of the proteins [16]. 

Various protein ingredients are utilized to satisfy nutritional requirements for protein quantity and quality in pet foods. Typical sources of protein ingredients are soybean oil meal, soybean flour, soy protein concentrate, soy protein isolate, meat meal, meat and bone meal, meat by-products, fish meal, blood meal, dried blood plasma, yeast, and milk protein (Balaz et al., 1977). In addition, vitamins, minerals, colorants, and other supplements such as choline chloride MgO vitamins A, Bj2,... 

Soybean is the dominant oilseed produced in the world, due to its favorable agronomic characteristics, its high-quality protein, and its valuable edible oil. It contributes over a half of all oilseeds produced worldwide (Figure 2.1). The US ranks first in soybean production (8.24 million tonnes), followed by Brazil, Argentina, China and EU-15 (4.28, 3.28, 3.26 and 2.87 million tonnes, respectively, see Chapter 1). The production of soybeans and soybean oil is driven by the need for soy protein meal, which is used extensively in commercial feeds for poultry, swine and cattle. Soybean oil accounted for 80-90% of total edible oil consumption in the US (USDA-NASS) in 1998 because of its... 

Protein supplements—The sources of extra protein are usually corn flour and soybean flour or meal, although other ingredients such as nonfat dry milk, fish flour, and derivatives of oilseeds (usually peanut, safflower seed, or sunflower seed) also may serve this purpose. These supplements raise both the quantity and quality of protein so that the macaroni and noodle products may be substituted for part of the dietary animal protein. 

These products must contain at least 20% protein with a quality at least 95% that of case in (a major protein in cow s milk). The supplemental protein may be supplied by flours or meals made from nonwheat, cereals or oilseeds such as soybeans, peanuts, sunflower seeds, and cottonseeds. 

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