Nutritional contribution of soy protein to food systems

From the nutritional point of view, soybeans can play a significant role in at least three aspects: as a source of supplementary and complementary protein, as a source of calories, and as a source of nitrogen. The protein role is probably the most important for food systems of developed and underdeveloped populations, while the role as a source of protein and calories applies more to food systems of developing populations. Soy protein efficiently supplements cereal grain protein, because it corrects the lysine deficiency of cereals. In some cases, for example with maize, it also corrects the tryptophan deficiency. On the other hand, the essential amino acid pattern of soybean protein complements that of other protein sources, for example cereal grains, cottonseed flour, and, in general, lysine deficient protein sources. This makes feasible the preparation of foods of optimum protein quality and of a high protein content. Because of its quality, soybean protein can replace animal protein without a significant decrease in nutritive value, for example as milk and meat extender; for diets low in quantity and quality of protein and deficient in calories, soybeans, as full‐fat flour, provide both. Because of cultural eating habits, it is difficult to conceive the use of soybeans as complete substitutes of common beans; therefore, efforts should be made to use soy protein in combination with common foods used by populations to whom soybeans are foreign food. Examples of the nutritional benefits derived from the use of soybean protein as flour or protein concentrate or as full‐fat soybean flour are given, particularly for foods consumed in Latin American countries. Besides the role soybeans play in human foods, they also play a significant role in the animal industry as a very important component of diets. The efficiency of the swine and poultry industry would be lower if it were not for the nutritional contribution of soybeans.