Epr spectroscopy studies on dpph free radical scavenging activity of dry red wines and their relationship with total polyphenols content | 电子顺磁共振波谱仪分析干红葡萄酒DPPH清除能力及其与总酚含量的关系

Chinese. 【目的】分析不同酿酒葡萄品种所酿制的干红葡萄酒抗氧化性的差异及其与总酚含量之间的关系。【方法】利用电子顺磁共振波谱仪（Electron Paramagnetic Resonance, 简称EPR）和福林-肖卡法（Folin-Ciocalteu，简称FC）分别对河北沙城产区5个单品种干红葡萄酒检测DPPH清除率和总酚含量，筛选适当的EPR试验条件。【结果】干红葡萄酒具有很强的抗氧化能力，在样品稀释200倍、反应时间5 min的条件下，各样品清除DPPH自由基的能力以赤霞珠葡萄酒为最强72.31%，宝石解百纳72.23%，梅鹿辄68.31%，西拉和增芳德分别为59.03%和56.34%。梅鹿辄、宝石解百纳和赤霞珠葡萄酒的总酚含量，分别为3 044.43、3 026.92和2 886.81 mg•L-1。西拉和增芳德葡萄酒的总酚含量相对较低，分别为2 085.51 mg•L-1和1 647.64 mg•L-1。【结论】电子顺磁共振法可以简便、快速检测干红葡萄酒的抗氧化性，不同单品种干红葡萄酒DPPH清除能力表现明显不同，自由基清除率与总酚含量之间存在线性正相关，回归方程y=0.01116x+37.327665，相关系数rGAE/DPPHequiv=0.91753。

English. 【Objective】 The purpose of this study was to compare the antioxidant capacities of dry red wines and analyze their relationship with total polyphenol content. 【Method】 The antioxidant properties of five monoverietal dry red wine samples (from the Shacheng viticultural region of China,) were investigated by Electron Paramagnetic Resonance (EPR) spectroscopy using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical as oxidants, and their total polyphenols content were analyzed by FC method. 【Result】Generally, the dry red wines which were diluted 200 folds showed high antioxidant in 5 min reaction time, the DPPH scavenging rate of Cabernet was 72.31% which was the highest, Ruby Cabernet 72.23%, Merlot 68.31%, Shiraz 59.03% and Zinfandel 56.34%；the total polyphenols content of Merlot was the highest at 3 044.43 mg•L-1, Ruby Cabernet 3 026.92 mg•L-1, Cabernet 2 886.81 mg•L-1, Shiraz 2 085.51 mg•L-1 and Zinfandel 1 647.64 mg•L-1. 【Conclusion】 It is an efficient method in detecting the antioxidant capacities of wines by EPR method. The DPPH scanvenging activity from dry red wines showed obviously difference. There was a linear correlation between the antioxidant activities and the total polyphenols content, y=0.01116x+ 37.327665, rGAE/DPPHequiv=0.91753.