Soy Protein

Soy protein is generally regarded as the storage protein held in discrete particles called protein bodies, which are estimated to contain at least 60 70 of the total soybean protein. Upon germination of the soybean, the protein will be digested, and the released amino acids will be transported to locations of seedling growth. Legume proteins, such as soy and pulses, belong to the globulin family of seed storage proteins called leguminins 11S Globulin Fraction and vicilins 7S Globulin , or in the case of soybeans, glycinin and beta-conglycinin. 1 2 Grains contain a third type of storage protein called gluten or "prolamines." Soybeans also contain biologically active or metabolic proteins such as enzymes, trypsin inhibitors, hemagglutinins, and cysteine proteases very similar to papain. The soy cotyledon storage proteins, important for human nutrition, can be extracted most efficiently by water, water plus dilute alkali pH 7 9 , or aqueous solutions of sodium chloride 0.5 2 M from dehulled and defatted soybeans that have undergone only a minimal heat treatment so that the protein is close to being native or undenatured. 3 Soybeans are processed into three kinds of modern protein-rich products soy flour, soy concentrate, and soy isolate.

Soy protein 90 protein N x 6.25 on a moisture-free basis has been available since 1936 for its functional properties. In 1936, American organic chemist Percy Lavon Julian designed the world's first plant for the isolation of industrial-grade soy protein. The largest use of industrial grade protein was, and still is, for paper coatings, in which it serves as a pigment binder. However, Dr. Julian's plant must have also been the source of the "soy protein isolate" which Ford's Robert Boyer and Frank Calvert spun into an artificial silk that was then tailored into that now famous "silk is soy" suit that Henry Ford wore on special occasions. The plant's eventual daily output of forty tons of soy protein isolate made the Soya Products Division into Glidden's most profitable division.

At the start of WWII, Glidden sent a sample of Julian's isolated soy protein to National Foam System Inc. today a unit of Kidde Fire Fighting of Philadelphia,PA, which used it to develop Aero-Foam, the US Navy's beloved fire-fighting "bean soup" while not exactly the brainchild of Percy Lavon Julian, it was the meticulous care given to the preparation of the soy protein that made the fire fighting foam possible. When a hydrolyzate of isolated soy protein was fed into a water stream, the mixture was converted into a foam by means of an aerating nozzle. The soy protein foam was used to smother oil and gasoline fires aboard ships, and was particularly useful on aircraft carriers. It saved the lives of thousands of sailors.

In 1958, Central Soya of Fort Wayne, Indiana acquired Julian's Soy Products Division Chemurgy of the Glidden Paint Company, Chicago. Recently, Central Soya's Bunge Protein Division, in January,2003, joined merged with DuPont's soy protein business Solae , which in 1997 had acquired Ralston Purina's soy division, Protein Technologies International PTI in St. Louis. Eighth Continent, an "ersatz" soy milk, is a combined "venture" product of DuPont and General Mills.

Food-grade soy protein isolate first became available on October 2, 1959 with the dedication of Central Soya's edible soy isolate, Promine D, production facility on the Glidden Company industrial site in Chicago. An edible soy isolate and edible spun soy fiber have also been available since 1960 from the Ralston Purina Company in St. Louis, who had hired Boyer and Calvert. In 1987, PTI became the world's leading maker of isolated soy protein.

Soy protein is used in a variety of foods such as salad dressings, soups, imitation meats, beverage powders, cheeses, non-dairy creamer, frozen desserts, whipped topping, infant formulas, breads, breakfast cereals, pastas, and pet foods.