Antioxidant activity of xanthan oligosaccharides prepared by different degradation methods

► Two kinds of xanthan oligosaccharides with similar molecular weights were prepared by different degradation methods. ► XGOS-B (prepared under alkaline condition) showed better antioxidant activity than XGOS-A (prepared under acidic condition). ► The antioxidant activity of xanthan oligosaccharides was influenced by the pyruvate acid content and reducing sugar content. ► The relationship of antioxidant activity and degradation method was revealed.