1.National Research and Development Branch Center for Shellfish Processing (Zhanjiang)，Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety，Guangdong Provincial Engineering Technology Research Center of Seafood，Guangdong Province Engineering Laboratory for Marine Biological Products，Key Laboratory of Advanced Processing of Aquatic Product of Guangdong Higher Education Institution，College of Food Science and Technology，Guangdong Ocean University，Zhanjiang 524088，China；2.Shenzhen Institute of Guangdong Ocean University，Shenzhen 518108，China；3.Collaborative Innovation Center of Seafood Deep Processing，Dalian Polytechnic University，Dalian 116034，China
Abstract: To investigate the hypoglycemic effects and digestive stability of oyster peptides, the oyster peptides were prepared from Hong Kong oyster (Crassostreahongkongensi). Structural characteristics, hypoglycemic activity and digestive stability of prepared oyster peptides were investigated invitro by hypoglycemic model and simulated gastrointestinal digestion model. The anthocyanin was also used to improve the digestive stability and hypoglycemic activity of prepared oyster peptides. The results showed that the prepared oyster peptides were rich in hydrophobic amino acids, and the relative molecular mass was mainly less than 1 000. The spectrum analysis showed that prepared oyster peptides contained 15 peptide sequences mainly including LYF, TLFLK, IRAGYD, TLHHRVH, ARNEANVNIY, and CVIGR, which had typical structure characteristics of hypoglycemic peptides. The half inhibition concentration (IC50) of prepared oyster peptides against α-amylase, α-glucosidase and dipeptidyl peptidase Ⅳ (DPP-Ⅳ) was (3.66±0.47), (8.62±0.66) and (2.60±0.46) mg/mL, respectively, exhibiting good hypoglycemic activity. However, the digestive stability of prepared oyster peptides was weak. After simulated gastrointestinal digestion invitro, the inhibition rate against the above three enzymes significantly decreased by 6.23%-32.48% (P<0.05). Therefore, the synergistic effects of anthocyanin with prepared oyster peptides were investigated. Through the synergy matrix design, the highest single agent (HSA) model was selected to calculate the synergistic effects of anthocyanin with prepared oyster peptides. The results showed that the oyster peptide and anthocyanin complex had significant synergistic inhibitory effects against α-amylase (HSA synergistic score 3.632), α-glucosidase (HSA synergistic score 3.503) and DPP-Ⅳ (HSA synergistic score 3.156). Moreover, the results of simulated gastrointestinal digestion experiment invitro showed that the anthocyanin could improve the digestive stability of prepared oyster peptides. The results of this study indicate that oyster peptides have the characteristic structure of hypoglycemic peptides, and oyster peptides and anthocyanins have synergistic effect in enhancing hypoglycemic activity and digestive stability.
2023, Vol. 38 
