Extraction, Identification and Hypoglycemic and Lipid-lowering Activity of Polyphenols from Aronia melanocarpa

The extraction process, composition and hypoglycemic and lipid-lowering activity of Aronia melanocarpa polyphenols (AMP) extracted by ultrasonic-assisted deep eutectic solvents were investigated. The optimal process was obtained by single factor experiment and Box-Behnken response surface method. The AMP components purified by macroporous resin were identified and analyzed by ultra performance liquid chromatograph mass spectrometer (UPLC-QTof-MS/MS). Finally, the inhibitory ability of α-glucosidase and pancreatic lipase was determined by simulating the digestibility of gastrointestinal tract in vitro. The results showed that the molar ratio of DES-2 (choline chloride-lactic acid) was 1:3, the water content was 80%, the ultrasonic power was 240 W, and the ultrasonic time was 40 min. The highest yield of AMP was 51.27 mg/g. There were 45 components in the purified AMP extracted by DES, including 15 anthocyanins, 3 proanthocyanidins, 18 flavonoids, and 9 phenolic acids. The total content was 116.92±7.54 mg/g, and its composition and content were significantly higher than those extracted by traditional organic solvents. After oral, gastric and intestinal digestion, the inhibition rate of AMP purified product on α-glucosidase reached 30.4%±1.2%, which was 3.34 times that of blueberry polyphenol purified product (P<0.05), and the inhibition rate of pancreatic lipase reached 92.7%±2.9%, which was 1.04 times that of blueberry polyphenol purified product (P<0.05). Compared with traditional organic solvents, DES extraction of AMP has high extraction efficiency, high yield, no pollution, many components and strong activity, and has certain feasibility of food industry application.