Characterization of a soy protein hydrolyzate for the development of a functional ingredient.

Argentina is a leading country in biodiesel production from soy. Extruded soy is a low-cost byproduct of the soybean oil industry, from which animal feeds are prepared as well as flour for human consumption. Soy proteins can be isolated from flours and digested with enzymes in order to obtain bioactive fractions. In this work, a commercial soy isolate (PRO-FAM 974) was characterized. Maximal solubility was achieved at a concentration of 90 mg/mL. Protein profiles obtained by SDS-PAGE showed that the isolate was constituted mostly by globulins. Conformational and thermal analyses (differential scanning calorimetry) showed that proteins were almost completely denatured. The isolate was hydrolyzed with a commercially available enzyme (COROLASE 7089). The peptide profile (MALDI-TOF) showed peptides ranging from 800 to 10,000 Daltons. We conclude that the product obtained has the potential to be used as functional ingredient for the development of functional foodstuffs, giving the opportunity to add value to the byproducts of the soybean oil industry.