Bioactive properties of peptide fractions from Brazilian soy protein hydrolysates: In silico evaluation and experimental evidence

Soybeans are a known source of dietary proteins and potential bioactive peptides. In this study, a protein hydrolysate from soybean protein concentrate was produced using papain. The peptides were separated by ultrafiltration (< and > 3 kDa, LMMH (low molecular mass) and HMMH (high molecular mass), respectively) and sequenced through LC-MS/MS. To obtain a thorough identification of the peptides in the hydrolysate, different analysis methods and bioinformatics techniques were applied, covering a molecular mass range from more than 480 Da up to small dipeptides. The antioxidant and the inhibitory α -glucosidase and lipase potentials were evaluated by different in vitro tests. Sixty-nine peptides were identified in the HMMH fraction and 32 in LMMH, but only 16 matched the 118 sequences obtained by in silico simulated hydrolysis. Unlike previous reports, the HMMH fraction showed higher antioxidant activity, by all 5 in vitro methods applied, which was not accompanied by the in silico evaluation. Both high and low molecular mass fractions showed similar inhibitory activities against α -glucosidase and pancreatic lipase. LMMH, however, showed better results for α -glucosidase inhibition (IC50 = 0,94), in agreement with the in silico evaluation. This combination of bioactivities makes the fractions of this hydrolysate potential food ingredients with the possible ability to delay the lipid peroxidation of meat products, limiting the digestion of lipids in the product and also with the potential to delay the digestion of carbohydrates ingested in the same meal.