木聚糖—铁复合物的制备工艺优化及抗氧化活性研究

以木聚糖(Xyl)与三氯化铁为底物,考察Xyl与柠檬酸钠质量比、制备温度及pH对产物得率的影响,通过响应面法优化以确定木聚糖—铁复合物(XPC)的制备工艺,采用红外光谱及X-射线衍射对Xyl和XPC结构进行表征和分析,并对XPC的DPPH自由基、羟基自由基、超氧阴离子自由基清除能力及还原能力进行研究。结果表明:制备XPC的最佳工艺条件为Xyl与柠檬酸钠质量比3:1,制备温度70℃,pH 8.0,该条件下的得率为66.59%,含铁量为22.57%。红外光谱及X-射线衍射分析表明,铁(Ⅲ)离子成功与Xyl螯合且未破坏其基本骨架。XPC对DPPH自由基、羟基自由基、超氧阴离子自由基的最大清除率分别为73.44%,30.95%,22.72%。与Xyl相比,XPC抗氧化性能显著提高。

Optimization on preparation technology of xylan polysaccharides iron complex and its antioxidant activities

Taking xylan(Xyl)and ferric chloride as substrates,the effects of the mass ratio of Xyl to sodium citrate,reaction temperature and pH on yield rate was investigated by single factor test.Preparation technology of xylan polysaccharides iron complex(XPC)was optimized by response surface methodology.The preliminary structure characterization of Xyl and XPC was performed by infrared spectroscopy and X-ray diffraction.The DPPH free radical,superoxide anion,hydroxyl radical and reducing power of XPC was also studied.The results showed that the optimum preparation conditions were as follows:the mass ratio of Xyl to sodium citrate of 31,reaction temperature of 70℃and pH of 8.0.Under the optimal conditions,the yield of XPC was 66.59%,and the iron content was 22.57%.Infrared spectroscopy and X-ray diffraction confirmed that iron(III)ions were successfully chelated with Xyl without destroying its basic framework.The maximum scavenging rates of XPC to DPPH,hydroxyl and superoxide anion radicals were 73.44%,30.95%and 22.72%,respectively.Compared with Xyl,the antioxidant activities of XPC significantly increased.