Pressure-dominated steam explosion for modifying textured soy proteins: Structure and in vitro digestion kinetics

Textured Soy Proteins (TSPs) have been employed as building blocks in various food processes, but their availability remains limited. In this research, influence of Steam Explosion (SE) with pressure ranges (0, 0.5, 1.0, 1.5 MPa) on the structure and in vitro digestibility of TSPs was investigated. The results showed that 0.5 and 1.0 MPa significantly increased the relative content of β-sheets and decreased the relative content of α-helices and β-turns. Correlation analysis revealed that the structural changes made the TSP brittle, with lower thermal stability and resistance to digestion. Moreover, SE decreased the degree of hydrolysis of TSPs in the gastric stage, with the lowest degree observed for the TSP at 0.5 MPa. However, in the intestinal phase, 1.0 and 1.5 MPa significantly increased the hydrolysis degree. These findings provide a better understanding of the SE pressure-modulated quality characteristics of TSPs and suggest the processing potential of modified TSPs as functional ingredients.