Optimization of Enzymatic Extraction Process and in Vitro Hypoglycemic Activity of Blackberry Polysaccharides

To optimize the extraction process of blackberry polysaccharide and investigate its hypoglycemic activity in vitro, this study used enzymatic extraction to extract blackberry polysaccharide. The effects of pectinase addition, material-liquid ratio, extraction temperature, and extraction time on the yield of blackberry polysaccharides were analyzed. Based on the results of the one-way experiments, the extraction of the blackberry polysaccharide enzyme was optimized using response surface design. The structure of blackberry polysaccharide was characterized by Fourier transform infrared spectroscopy and monosaccharide composition analysis, and its inhibitory capacity on α-glucosidase and α-amylase in vitro were also studied. The results showed that, the optimal conditions for extracting blackberry polysaccharide were 0.42% pectinase, material-liquid ratio of 1:6 g/mL, extraction temperature of 55 ℃, and extraction time of 84 min. Under this condition, the yield of blackberry polysaccharide was 10.68%±0.03%. The extracted blackberry polysaccharide was an acidic polysaccharide with a β-pyranose configuration and exhibited good inhibitory activity against α-glucosidase and α-amylase. The semi-inhibitory concentrations were 0.061 and 0.36 mg/mL, respectively. The enzymatic extraction process optimized in this study can effectively extract blackberry polysaccharides. The extracted blackberry polysaccharides exhibit good in vitro hypoglycemic activity, providing a basis for the potential application of blackberry polysaccharides in the development of hypoglycemic functional foods.