Preparation of oligosaccharides from Chinese yam and their antioxidant activity.

In the present study, the oligosaccharides from Chinese yam were prepared by hydrolysis with hydrogen peroxide (H2O2), which can cleave the glycosidic bonds in polysaccharides. The hydrolysis conditions were optimised by using a central composite design (CCD) as follows: reaction time 4.02 h, temperature 84.35 °C, and H2O2 concentration 2.46%, under which the yield of Chinese yam derived oligosaccharides (CYOs) reached 11.73%, which was consistent with the predicted yield by analysis of the results of CCD (11.89%). The CYOs products were partially characterised by chemical component and Fourier transform infrared spectrum. The CYOs scavenged hydroxyl radical by 89.05% at the concentration of 100 μg/mL, indicating that the CYOs may be a viable option for use as a food antioxidant.