Optimization of factors affecting the antioxidant activity of soy protein hydrolysate by response surface methodology

The objective of this study was to produce soy protein hydrolysate (SPH) with the highest antioxidant activity, from soy protein isolate using enzymatic hydrolysis. The soy protein hydrolysate was produced through enzymatic hydrolysis by Alcalase 2.4L enzyme and the optimal hydrolysis parameters to achieve the highest antioxidant capacity of peptides were obtained by response surface methodology (RSM) with the central composite design (CCD) using the Design Expert software. The combined effects of temperature, time and enzyme activity on superoxide free radical scavenging capacity of SPH were well fitted to a quadratic equation by using Design expert software. The regression model presented a plateau region with maximum antioxidant activity (>62.38%) at the following critical values: temperature 49.710C, time 117.45 min and enzyme activity 66.27 Anson unit per kilogram protein. Results indicated the potential of soy protein hydrolysate to be applied as a natural antioxidant in food ingredient and pharmaceutical applications in the future.