High-pressure ultrasonic-assisted extraction of polysaccharides from Hovenia dulcis: Extraction, structure, antioxidant activity and hypoglycemic

In this study, high-pressure ultrasonic-assisted extraction (HUE) technology was used for polysaccharide extraction from Hovenia dulcis (HDPS). A maximal extraction yield (11.81 +/- 0.26%) was obtained using the response surface method (RSM) with optimized HUE conditions (Ultrasound power 330 W, 68 degrees C, and 22 min). Results showed that HDPS mainly contained neutral sugar (47.81 +/- 1.56%), uronic acid (12.52 +/- 0.15%), and protein (3.64 +/- 0.24%), specifically. HDPS was comprised of mannose, rhamnose, galacturonic acid, glucose, galactose and arabinose in a molar ratio of 3.20%, 20.40%, 4.81%, 11.14%, 2737% and 33.08%, respectively. And with an average molecular weight of 18522 kDa for its major component (accounting for 90.13% for HDPS). The result obtained from the X-ray diffraction pattern confirmed a semi-crystalline nature of the sample. HUE-HDPS suggested typical shear thinning behavior and non-Newtonian properties. Additionally, HUE-HDPS exhibited better chemical antioxidant activities in DPPH,ABTS, hydroxyl radical scavenging and Fe2+ chelation activity. The in-vitro and in-vivo experiments indicated that HUE-HDPS had obviously hypoglycemic effects. Accordingly, the polysaccharides from Hovenia dulcis might serve as a natural antioxidant and hypoglycemic agent. (C) 2019 Elsevier B.V. All rights reserved.