Abstract:To investigate the optimal protease combination for the preparation of antioxidant peptides from sunflower seed protein and to identify antioxidant peptide sequences in the hydrolysates，sunflower seed protein was hydrolyzed using different combinations of dual or triple proteases. The antioxidant activities of the resulting hydrolysates were evaluated by measuring their DPPH free radical scavenging activity and total antioxidant capacity. In addition，their effects on superoxide dismutase activity，malondialdehyde content，and glutathione content in atrophic C2C12 myotubes were assessed to further screen the optimal protease combination and determine the peptide molecular weight fractions with the strongest antioxidant capacity. Antioxidant peptides were subsequently identified by peptide sequencing and antioxidant activity prediction scoring. The results showed that among the hydrolysates generated by different protease combinations，peptides produced by the combined hydrolysis with trypsin，papain，and alkaline protease exhibited the strongest antioxidant activity.Furthermore，peptides with a molecular weight below 1 kDa demonstrated significantly higher antioxidant capacity than those in other molecular weight fractions. Ultimately，five antioxidant peptides were identified，with the sequences LLPYYPN，LLPYYPNT，FSPHWTVN，GVAPGPVWTP，and AIQSPHWT.