Preparation of xanthan-derived oligosaccharides and their hydroxyl radical scavenging activity.

In this study, the xanthan-derived oligosacchrides were prepared by hydrolysis of xanthan using hydrogen peroxide (H(2)O(2)) in alkaline solution. The hydrolysis process was monitored by the dextrose equivalent values of the hydrolysates. The optimal hydrolysis conditions were found to be reaction time 24 h, temperature 65 °C, H(2)O(2) concentration 1.6% (v/v), and NaOH concentration, 3 M. Under these optimized conditions, the maximum dextrose equivalent value (7.53%) was observed. The structure of the hydrolysates were characterized by Fourier-transform infrared spectroscopy. The xanthan-derived oligosacchrides showed high hydroxyl radical scavenging activity. The xanthan-derived oligosacchrides content of the product and the yield were 96.8% and 95.7% (w/w), respectively.