Physicochemical properties and prebiotic activities of polysaccharides from Zizyphus jujube based on different extraction techniques

Zizyphus jujube polysaccharide was extracted with hot water, ultrahigh pressure, deep eutectic solvent (DES) and ultrahigh pressure-assisted DES. Comparative analyses were conducted on the yield, physicochemical properties and prebiotic activity of four polysaccharides (JP-H, JP-U, JP-D and JP-UD). The yield of JP-UD (10.42 %) was 3.3 times that of JP-H (3.12 %), and its sugar content was the highest. JP-UD possessed the lowest Mw, while JP-H possessed the highest. Four JPs were acidic pyranose and mainly composed of galacturonic acid, arabinose and galactose. NMR results demonstrated that they contained not only similar glycosidic linkage but also the specific glycosidic linkage of →4)-α-D-Glcp-(l→ appeared in JP-U and JP-UD, the esterified units of GalA and CONH2 group appeared in JP-D and JP-UD, and the Terminal β-D-Galp and →4)-α-GalpA-(1→ appeared in JP-UD. JPs showed different proliferation effects on four lactobacillus strains, among which JP-UD exhibited the strongest prebiotic activity. Zizyphus jujube polysaccharides have great potential for application in the functional food and medical industry.