Preparation and antioxidant activity of Pteridium aquilinum-derived oligosaccharide

In this study, Pteridium aquilinum-derived oligosaccharides (PAO) were prepared from Pteridium aquilinum polysaccharides by hydrolysis using hydrogen peroxide and their hydroxyl radical scavenging activity was investigated. The hydrolysis process was monitored by the yield of PAO. Factors affecting the hydrolysis of Pteridium aquilinum polysaccharides were investigated by using the response surface methodology, and the optimum hydrolysis conditions were determined as follows: time, 6.99 h; temperature, 56.82 °C; H2O2 concentration, 3.2% (v/v). The hydrolysates were filtered, concentrated to ~25% (w/v), precipitated with 6 volumes of ethanol, freeze-dried, and ground to yield a water soluble and white powder. The sugar content of the product was 96.8%, and the yield was 5.29% (w/w), respectively. The PAO show high hydroxyl radical scavenging activity (82%) at the concentration of 80 μg/mL.