Characterization, Antioxidant Activities and Optimization of Preparation Process of a Auricularia Polytricha Polysaccharide-Zinc (II) Complex

In our previous work, a novel polysaccharide APP3a from Auricularia polytricha was successfully isolated and purified. Response surface methodology was used to optimize the preparation process of APP3a-Zn on the basis of the single factor experiments. Characterization of APP3a-Zn was carried out and its antioxidant activity was also investigated. The result showed that the best preparation process of APP3a-Zn was chelation time 4.45 h, chelation temperature 49.37°C and pH 4.68. The weight loss of APP3a-Zn was slightly smaller than that of APP3a within the heating temperature range and the crystal structure of APP3a-Zn had undergone tremendous changes compared with APP3a. APP3a-Zn had stronger antioxidant activity than APP3a. The results indicated that chelation with zinc enhanced the antioxidant activity of APP3a. In the food industry, APP3a-Zn had great potential as a new zinc supplement with antioxidant activity.