Effect of chickpea protein hydrolysate on multi-scale structure and in vitro digestive properties of rice starch

The effects of chickpea protein hydrolysates (CPH) with different hydrolysis times (30 min, 60 min, and 120 min) and different amounts (5%, 10%, and 20%) on the multi-scale structure and digestibility of rice starch (RS) were investigated. The addition of CPH did not change the recrystallization of rice starch compared to pure rice starch. The addition of CPH increased the pasting temperature of starch, decreased the enthalpy of pasting, and effectively inhibited the pasting of starch. In vitro digestion results showed that the interaction between CPH and rice starch significantly reduced the digestibility of rice starch. The content of rapidly digestible starch in the RS-10% CPH120 complex decreased from 50.41% to 40.56%. However, the addition of 20% CPH hydrolyzed for 120 min may inhibit the non-covalent interaction between RS and CPH due to the aggregation of more short peptides. The RDS content in the complex RS-20% CPH120 (41.98%) was higher than that of RS-10% CPH120 (40.56%). In conclusion, our work demonstrates for the first time that CPH has a significant inhibitory effect on starch digestion.