Physicochemical and antioxidant properties of Lycium barbarum seed dreg polysaccharides prepared by continuous extraction

Lycium barbarum seed dreg polysaccharides (LBSDPs) were continuously extracted with four different solvents [hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS), and concentrated alkaline (CASS)]. The present study characterized the physicochemical and anti-oxidant based functional properties of different LBSDPs. The monosaccharide analysis revealed xylose (64.63%, 70.00%, 44.71%, and 66.67%) as the main sugar with the molecular weights of 5985, 7062, 5962, and 8762 Da in HBSS, CHSS, DASS, and CASS, respectively. Among the four polysaccharides, CASS had the strongest DPPH radical scavenging ability and reducing power; while, CHSS had the strongest ferrous ions chelating ability and HBSS showed the strongest OH radical scavenging ability. In terms of functional properties, HBSS and CASS had better solubility and oil holding capacity, while, CASS and CHSS had higher foam capacity and foam stability. Altogether, the polysaccharides extracted from L. barbarum seed dreg exhibit a potential application prospect in functional food and cosmetics industries.