Autolysis Process of Shrimp By-products and Identification of Potential Antifreeze Peptides

In order to strengthen the high-value processing and utilization of marine by-products, shrimp by-products were used in this study. The autolysis reaction was carried out in a water bath at 50 ℃ and pH(7.81~7.83), then the enzymatic hydrolysate was heated in water bath at 95 ℃ for 20 min to inactivate endogenous enzymes. This paper studied the changes in the polypeptide composition of the enzymatic hydrolysis products during the process, and screened the antifreeze peptide sequences based on the activity prediction platform, and provided a method for screening active peptides with high efficiency. When the autolysis treatment was 0~3 h, the content of degree of hydrolysis (DH) and TCA soluble peptides in the enzymatic hydrolyzate increased sharply, reaching 49.8% and 26.1 mg/g, respectively, and then the growth rate slowed down. 1301 peptides were detected in the 0.5 h enzymatic hydrolysis product (A-0.5), and 197 in the 3 h enzymatic hydrolysis product (A-3). The content of peptides greater than 1600 Da in A-0.5 reached 69.5%, while the peptides in A-3 were dominated by 600~1600 Da. Based on the activity prediction platform Cryoprotect, 7 sequences of QVHPDTGISS, GYGCARPNYPGV, TTGEVCDSGDGVTH, EQICINFCNEK, DEYEESGPGIVH, DIDNDGFLDK and DIDNNGFLDK were screened as antifreeze peptides, and the source of the peptides was obtained by enzyme cleavage simulation.