Effect of high hydrostatic pressure on Alcalase-assisted hydrolysis of soy protein isolate and the anti-aging activity of the hydrolysates

Abstract

In this study, soy protein isolate hydrolysates (SPIH) with enhanced antiaging activity were produced. SPIH were generated by Alcalase hydrolysis of soy protein isolate (SPI) pretreated under high hydrostatic pressure (HHP: 200–500 MPa, 5–15 min). Results showed HHP treatment led to the transition of secondary structures of SPI, withα-helix and β-sheet transforming into random coil and β-turn. The dense network structure of SPI was disrupted, increasing the hydrolysis degree by 19.2 % (300 MPa, 5 min). Attributed to the radical scavenging effect by the surface exposure of hydrophobic residues, the antioxidant activity of HHP-treated SPIH were increased and reached a peak under the condition of 300 MPa for 5 min. In yeast cell anti-aging assays, HHP-treated SPIH decreased the accumulation of reactive oxygen species and malondialdehyde content, thereby delaying cellular aging. These findings demonstrated that HHP-assisted enzymatic hydrolysis enhanced the yield and bioactivity of anti-aging ingredients derived from SPI, providing a novel strategy for developing functional food.