2.8.1. Assay for erythrocyte hemolysis

The erythrocyte oxidative hemolysis protection of peptides on AAPH‐induced was investigated based on the method of Wenzhen Liao (Liao et al., ²⁰¹⁴). Erythrocytes were obtained by centrifuged at 1200 g at 4°C for 10 min from blood sample which was collected from healthy adult volunteers and washed three times with PBS (pH 7.4). The erythrocytes were mixed with 4‐fold PBS to obtain the erythrocyte suspension. 200 μL erythrocyte suspension was added to 200 μL PBS or the soybean peptides with different concentration. The mixture was gently incubated for 30 min at 37°C and then 400 μL 0.2 mmol/L AAPH was added to incubate for another 2 h. After incubation, the reaction solution was diluted with 3.2 mL PBS and centrifuged for 10 min at 1200 g at 4°C. The absorbance of the supernatant was measured at 540 nm which regard as the sample treated group. To achieve the 100% hemolysis, the ultrapure water was added to the suspension. All experiments were performed in triplicate. The hemolysis inhibition rate was calculated as the follow: