Recovery of Proteins from Squid By-Products with Enzymatic Hydrolysis and Increasing the Hydrolysate’s Bioactivity by Maillard Reaction

The Maillard reaction is an effective method for enhancing the activity of bioactive peptides. In this study, squid by-product hydrolytic peptides (SPHPs) were obtained. The effects of the Maillard reaction on the antioxidant and antibacterial activities of the SPHPs were explored. The results showed most of the peptides in the < 500 Da fraction of SPHPs reacted with D-arabinose to form the 500–1000 Da fraction (89.60%). The Maillard reaction products (MRPs) possessed more potent antioxidant activities, including free radical scavenging activity, ferrous chelating capacity, and reducing power, than the SPHPs. Although both the SPHPs and MRPs had broad-spectrum antibiotic activities and could inhibit the growth of both gram-negative and gram-positive bacteria, the antibacterial activities of the MRPs were higher than those of the SPHPs. Furthermore, the efficacy of the MRPs lasted significantly longer than that of ampicillin and could last for more than 30 days. In addition, both the SPHPs and MRPs had good functional properties and many potential applications. The results suggested that the Maillard reaction has potential to be used to improve the activities and physicochemical properties of bioactive peptides.