Optimization of stepwise dual-enzymatic preparation of collagen peptides from squid skin

One-factor-at-a-time and orthogonal array methods were used to investigate the optimization of stepwise dual-enzymatic preparation of collagen peptides from squid skin in this work. The optimum extraction conditions of alcalase and papain: firstly, Alacalase hydrolyzed for 3 h under the conditions of 50 ℃, p H 10.0 and enzyme concentration 0.3%, then papain hydrolyzed for 2 h under the conditions of 55 ℃, p H 8.0 and enzyme concentration 0.2%. Under these condition, the maximum DH was 24.32%, the DPPH scavenging rate was 90.34% and recovery ratio of peptides was 58.68%. SDS-PAGE was used to analysis the molecular weight range of collagen peptide, result showed the molecular weight mostly less than 3000 u.