Improvement of the Antioxidant Activity of Soybean Peptides by Microwave-Assisted Enzymatic Digestion

摘要

Objective: To optimize the enzymatic digestion processing parameters of soybean and improve the antioxidant activity of soybean peptides. Methods: microwave-assisted enzymatic digestion (MAED) was applied to extract antioxidant peptides from soybean with maximized antioxidant activity by response surface methodology coupled with an one-factor-at-a-time design. The hydroxyl radical, DPPH radical, superoxide anion radical and ABTS radical scavenging activity were used to evaluate the antioxidant power of the products. Results: The optimal processing parameters for MAED were 31 min for microwave time, 56°C for microwave temperature, 500 W for microwave power, 8.09 for pH value, 5:100 for ratio of enzyme to soybean protein powder and 50 mg/mL for concentration of soybean protein powder. Under these conditions, soybean peptides demonstrated stronger antioxidant activities than soybean peptides without MAED (P< 0.05). The IC_(50) value of DPPH radical, superoxide anion radical and ABTS radical scavenging of the final soybean peptides are 0.652 ± 0.007 mg/mL, 1.250 ± 0.046 mg/mL and 0.674 ± 0.008 mg/mL, respectively. Conclusion: The results suggested that the MAED technology has potentials to improve the antioxidant activity. Much more work should be done in the future to clarify the relation between the improved antioxidant activity and the changed functional groups.