Effects of non-starch polysaccharides from pure wheat malt beer on beer quality, in vitro antioxidant, prebiotics, hypoglycemic and hypolipidemic properties

Pure wheat malt beer (PWMB) with potentially functional properties may attract consumer interest. To explore the functional properties of non-starch polysaccharides (NSPs) in PWMB, NSPs were extracted from PWMB and separated into PWMB non-starch polysaccharides-1 (PNSP-1) and PWMB non-starch polysaccharides-2 (PNSP-2) by Q-Sepharose Fast Flow column. PNSP-1 exhibited more effects on increasing the viscosity of beers, which had higher purity of 92.58% containing 88.53% arabinoxylan with arabinose/xylose (A/X) 0.60 and 2.78% 8-glucan but no glucomannan and mannan; while PNSP-2 showed greater effects on promoting beer haze and foam retention, which had more diverse NSPs including 46.03% arabinoxylan with A/X 1.13, 41.47% arabinogalactan, 10.26% glucomannan, and 2.70% mannan but no 8-glucan. Diversity of sugar composition resulted in a better antioxidant capacity of PNSP-2. NSPs proliferated Lactobacillus casei LC6117 and LC0331, but did not promote L. plantarum LP-28 and L. fermentium LF-2H. PNSP-2 was also utilized by L. rhamnosus SRG. PNSP-2 had better effects on prebiotics activities. PNSP, PNSP-1 and PNSP-2 all exhibited mild inhibitory effects on alpha-glucosidase and lipase but not on alpha-amylase, and showed a binding capacity to fat and cholesterol. This work is of great reference significance for improving the viscosity, haze, foam retention and health value of wheat beer.