黑苦荞麦壳高聚原花青素降解及其抗氧化活性分析

Degradation of Polymeric Proanthocyanidins from Black Tartary Buckwheat Shells and Antioxidant Activity of Degradation Products

以黑苦荞麦壳为研究对象,采用固体酸催化剂降解黑苦荞麦壳高聚原花青素。通过单因素试验和正交试验,优化降解工艺条件,并对降解产物进行结构表征,考察其抗氧化能力。结果显示,筛选出的最适固体酸催化剂为Amberlyst-35(A-35),最佳降解工艺条件为催化剂添加量10%(质量分数)、催化时间40 min、催化温度65℃,在此条件下,高聚原花青素的平均聚合度从6.89降至2.37。傅里叶红外光谱分析显示降解产物具有原花青素的结构特征,降解效果良好。此外,降解产物的DPPH自由基、ABTS;自由基清除能力分别提高了1.92倍和4.78倍,亚铁离子螯合能力无显著性差异。黑苦荞麦壳高聚原花青素经降解后获得了较强抗氧化活性的低聚原花青素。

In this study,solid acid catalysts were used to degrade the polymeric proanthocyanidins from black tartary buckwheat shells. Through single-factor test and orthogonal test,the degradation conditions were optimized,and the structures of the degradation products were characterized to investigate their antioxidant activi-ties. The results showed that the optimum solid acid catalyst screened out was Amberlyst-35(A-35),and the optimal degradation conditions were listed below:10% catalyst addition(w:w),catalysis time of 40 min,and catalysis temperature of 65 ℃. Under these conditions,the average polymerization degree of the polymeric proanthocyanidins decreased from 6.89 to 2.37. The degradation products were characterized by Fourier transform in-frared spectroscopy(FTIR)and confirmed to have structural characteristics of proanthocyanidins,indicating a good degradation effect. In addition,the scavenging abilities of DPPH free radicals and ABTS;free radicals of the degradation products increased by 1.92 times and 4.78 times,respectively,and there was no significant difference in the chelating capacity of Fe;. In conclusion,polymeric proanthocyanidins from black tartary buckwheat shells were degraded to obtain oligomeric proanthocyanidins with strong antioxidant activity.