Ultrasonic-assisted extraction, analysis and biological activities of polysaccharide from white quinoa

The aim of this study was to investigate the optimal process conditions for the preparation of white quinoa polysaccharides and the bioactivity of white quinoa polysaccharides in vitro. This study used white quinoa as raw material and utilized ultrasound-assisted extraction to extract polysaccharides from white quinoa. The optimal extraction technology for white quinoa polysaccharides (WQP) was studied through response surface methodology (RSM) experiments. In addition, preliminary characterization of WQP and determination of their physicochemical properties were conducted. Determined the content of nutrients in WQP. The hypoglycemic, antioxidant, and lipid-lowering effects of WQP were evaluated by different in vitro experiments. The results showed that the yield of WQP was 2.11% under the optimal process. WQP inhibited α-glucosidase and α-amylase by 60.85% and 51.30%, respectively. The scavenging rates of ▪OH, DPPH, ABTS, and ▪O 2 − radicals were 48.36%, 67.17%, 74.87%, and 61.26% respectively. In addition, WQP has some choline-binding ability. It also inhibited cholesterol lipase and pancreatic lipase by 49.76% and 80.57% respectively. The present study demonstrated the glucose-lowering, antioxidative and lipid-lowering effects of white quinoa polysaccharide in vitro.