Soy protein concentrate (SPC) is made by treating the white soy flakes produced for soybean meal to aqueous alcohol extraction. This extraction process removes the soluble carbohydrate and significantly lowers the levels of lectins, trypsin inhibitors, glycinin, B-conglycinin, saponins, and oligosaccharides that are considered to be anti-nutritional factors (ANF) in regular soybean meal, which have been documented to have negative effects in some fish species such as gastrointestinal disturbances, intestinal damage, and increased disease susceptibility. The resulting traditional soy protein concentrate is then thermally processed to further reduce ANF’s and produce low-antigen, feed-grade SPC.
Low-antigen SPC has nutritional qualities that make it ideal for use in nutrient-dense aqua feeds for marine fish species, marine shrimp, and for fry and fingerling feeds of both freshwater and marine fish.
Research has also identified higher energy and nitrogen digestibility for SPC over soybean meal included in feed for fish.
Fermentation and other production technologies are also used to produce various forms of SPC.