Preparation of a Functional Beverage with Α-Glucosidase Inhibitory Peptides Obtained from Ginkgo Seeds

To obtain α-glucosidase inhibitory peptides from ginkgo seeds and use it to develop beverages, papain hydrolysis was used to hydrolyze and extract ginkgo seed peptides. Through ultrafiltration and semi-preparative high performance liquid chromatography, peptide fragments which were molecular weight of < 10 KDa with high α-glucosidase inhibition rate were separated and purified to prepare beverages. At the same time, the A1, A2, B1, and B2 peptide fragments purified by semi-preparative high performance liquid chromatography were analyzed for amino acid composition. All four peptide fragments have glutamate. Studies have shown that amino acids such as glutamate can promote postprandial insulin secretion and reduce glucose levels. The result indicates that the amino acid composition may be related to the inhibition rate of α-glucosidase. After orthogonal experiment design, analysis of variance and principal component analysis, when 5% xylitol and 0.3% citric acid were added, and the glycine content was 1.2%, the ginkgo polypeptides beverage had the best flavor.