Preparation and Evaluation of Antioxidant Activities of Bioactive Peptides Obtained from Cornus officinalis

The present study is a preparation of bioactive peptides from Cornus officinalis proteins by the compound enzymatic hydrolysis method. Response surface methodology (RSM) coupled with Box–Behnken design (BBD) is used to optimize the preparation process of Cornus officinalis peptides. The effects of independent variables, such as the amount of enzyme, pH value, time, extraction times and the ratio of material to liquid on the yield of peptides, are also investigated. The analysis results of the RSM model show that the optimum conditions for the extraction of Cornus officinalis peptides were a pH value of 6.76, temperature of 48.84 °C and the amount of enzyme of 0.19%. Under optimal conditions, the yield of peptides was 36.18 ± 0.26 %, which was close to the predicted yield by the RSM model. Additionally, the prepared Cornus officinalis peptides showed significant antioxidant activity; the scavenging rates of the peptides for DPPH and ·OH were 48.47% and 29.41%, respectively. The results of the cell proliferation assay revealed that the prepared Cornus officinalis peptides could promote embryo fibroblast cells proliferation and repair oxidative damage cells. These results have a practical application value in the design of novel functional food formulations by using Cornus officinalis.