The dual-function of bioactive peptides derived from oyster (Crassostrea gigas) proteins hydrolysates

Oysters (Crassostrea gigas) have a wide range of functionality due to their nutritional and bioactive components. However, the bioactive peptides of oyster proteins are rarely reported, particularly their anti-diabetes effects and antioxidants. Oyster proteins were extracted from fresh oysters using phosphate-buffered saline and simulated gastrointestinal digestion was performed. The degree of hydrolysis (DH), structural characterization, molecular weight (Mw) distribution, free amino acid, anti-diabetic activity, and antioxidant activity were studied during in vitro simulated gastrointestinal digestion. The results showed that the alpha-glucosidase inhibitory activity, alpha-amylase inhibitory activity, DPPH radical scavenging activity, and ABTS radical scavenging activity of the oyster protein gastrointestinal digest were increased (P < 0.05) from 0 to 33.96%, from 9.17% to 44.22%, from 9.01 mu g trolox/mg protein to 18.48 mu g trolox/mg protein, and from 21.44 mu g trolox/mg protein to 56.21 mu g trolox/mg protein, respectively. Additionally, the DH, beta-turn structure, fluorescence intensity, free amino acid, and short peptide content (Mw < 1 000 Da) increased in the simulated gastrointestinal digestion. These results indicate that the digestive hydrolysates obtained from oyster proteins could be used as natural anti-diabetic and antioxidant agents.(c) 2023 Beijing Academy of Food Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Oyster proteins obtained from fresh oysters showed increased anti-diabetic and antioxidant effects after simulated gastrointestinal digestion. The α-glucosidase inhibitory activity, α-amylase inhibitory activity, DPPH radical scavenging activity, and ABTS radical scavenging activity of the oyster protein gastrointestinal digest were significantly increased. Additionally, the degree of hydrolysis, beta-turn structure, fluorescence intensity, free amino acid, and low molecular weight peptide content also increased during simulated gastrointestinal digestion.