石榴花色苷的微波辅助提取及抗氧化活性研究

以陕西临潼甜石榴为试验材料，通过正交试验，采用pH 差示法测定石榴总花色苷含量，优化微波辅助提取石榴花色苷的工艺参数。同时，采用DPPH 法、FRAP 法、ABTS 法、螯合亚铁能力法分析石榴花色苷的体外抗氧化活性。结果表明：微波辅助提取石榴花色苷的最佳工艺参数为溶剂pH1、料液比1:13(g/mL)、提取时间210s、乙醇体积分数70%、微波输出功率360W。此条件下，花色苷得率为184.81μg/g。微波输出功率对石榴汁花色苷的提取得率有显著影响(P ＜ 0.05)。石榴花色苷含量与DPPH 自由基清除率、铁还原力、ABTS+ 自由基清除率和螯合亚铁离子有显著的相关性(相关系数R2 分别为0.9928、0.9925、0.9913、0.9945)，呈明显的量效关系，IC50 值分别为2.44、1.14、4.08、101.05mg/L。

Microwave-assisted Extraction and Antioxidant Activity Evaluation of Anthocyanins from Pomegranate (Punica granatum L.) Fruits

Pomegranate (Punica granatum L.) fruit is rich in anthocyanins, which has attracted great attention for its health benefits. The aim of this study was to optimize five parameters for the microwave-assisted extraction of anthocyanins from sweet pomegranate fruits from Lintong region, Shaanxi province and to evaluate the in vitro antioxidant activity of the extracted anthocyanins by DPPH radical scavenging, ferric reducing antioxidant power (FRAP), 2,2＇-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS+) and ferrous ion chelating assays. The optimal extraction parameters of anthocyanins were as follows: pH value 1; solid/liquid ratio 1:13; length of extraction time 210 s; microwave power 360 W; and ethanol concentration 70%. An anthocyanin yield of 184.81μg/g was achieved under these conditions. Microwave power had a significant effect on anthocyanin yield (P ＜ 0.05). The extracted anthocyanins had the ability to scavenge DPPH and ABTS+ radicals, ferric reducing antioxidant power and ferrous ion chelating capacity in a linear concentration-dependent manner, with corresponding correlation coefficients (R2) of 0.9928, 0.9925, 0.9913 and 0.9945, and the IC50 values were 2.44, 1.14, 4.08 mg/L and 101.05 mg/L, respectively.