The soybean plant (Glycine max) belongs to the legume family. It is able to utilize the nitrogen of the air through the action of bacteria on its roots. The protein content of the seed is about 40%. After the hulls and the oil are removed, the remaining defatted flake, which is the starting material for most commercial protein ingredients, has a protein content of about 50%. Soy protein can enhance the nutrional quality of other vegetable proteins. For example, soy protein products contain a level of lysine which exceeds human requirements and thus can correct lysine deficiency found in some protein containing grains, such as wheat or corn. Studies have shown that soy protein products are comparable in digestibility to other high quality protein sources such as meat, milk, fish and eggs. Many applications for soy protein products involve combinations with creal grains and/or alternate protein sources. Soy protein amino acid profiles (fich in lysine, limiting in sulfur amino acids) fit nicely with grain proteins (limited in lysine, rich in sulfur amino acids). (“Soy Protein Products, Characteristics, nutritional aspects and utilization. A publication of AOCS, ISBN 1-893997-28-8). 

Benefits of Soy Protein on Human Diseases

There is ample evidence that protein products have a positive influence on human disease such as cardiovascular disease (CVD) and several types of cancer. In addition, soy protein products can make a significnant contribution to weight reuction, mainly by providing essential high quality protein in a concentrated form for specially designed, low calorie/high nutrient desnity meals. (“Soy Protein Products, Characteristics, nutritional aspects and utilization. A publication of AOCS, ISBN 1-893997-28-8).

Soy Products

Soy milk: is prepared by an aqueous extract of the whole soybean.

Soy sauce: is made by fermentation of a combination of soybeans and creals, usually wheate. 

Tempeh: is preapred by cooked soybeans fermented by the mold Rhizopus oryzae (protein continet about 20% on a wet basis and 50% after drying). It is used in Indoesian cusine. 

Tofu (soy curd) is made by coagulation of soy milk. Tofu curd contains 88% moisture, 6% protein, and 3.5% oil. Tofu can be frozen, aged and drited (56% protein). (“Soy Protein Products, Characteristics, nutritional aspects and utilization. A publication of AOCS, ISBN 1-893997-28-8).