Preparation and antioxidant activity of Lycium barbarum oligosaccharides

In this study, the Lycium barbarum oligosaccharides (LBO) were prepared by hydrolysis using hydrogen peroxide (H2O2). The yield of the LBO was monitored during the hydrolysis process. The hydrolysis conditions were optimized as follows: time, 4 h; temperature, 70 °C; and H2O2 concentration, 2.5% (v/v). The hydrolysates were filtered, concentrated to ∼20% (w/v), precipitated with 6 volumes of absolute ethanol, freeze-dried, and ground to yield a water soluble and white powder. The sugar content of the product was 95.8%, and the yield was 21.05% (w/w), respectively. The LBO show higher hydroxyl radical scavenging activity (86.46%) than Vc (40.96) at the concentration of 100 μg/mL.