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, 4h; 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.