微量、快速测定葡萄与葡萄酒总酚

Rapid and Micro-Determination of Total Polyphenol in Grape and Grape Wine

基于Folin-Ciocalteu分光光度法的原理,借助微量移液器和微波处理,通过优化反应条件,建立一种新的微量、快速测定葡萄与葡萄酒总酚含量的方法。实验得到体系的最佳反应条件为0.1mL测试样品,0.1mL 1mol/L Folin-Ciocalteu试剂和0.8mL 60g/L Na2CO3溶液,在微波炉的中档下处理20s后测定765nm波长处的吸光度。以没食子酸为标准品作标准曲线,在质量浓度1～50mg/L范围内与吸光度呈良好线性关系(R2=0.9996)。对葡萄皮与葡萄酒进行加标回收率实验的平均回收率分别为98.1%和97.2%,精密度(n=9)测定相对标准偏差(RSD)分别为1.40%和1.01%。该方法不但量微、快速,而且操作简便,重复性好,结果精准可靠。

Based on the principle of Folin-Ciocalteu（F-C） assay for determining total polyphenol in grape and grape wine,a new method was developed by optimizing reactive conditions with the aid of micropipette and microwave irradiation.The optimal conditions were 0.1 mL of sample,0.1 mL of 1 mol/L F-C reagent and 0.8 mL of 60 g/L Na2CO3,microwave treatment for 20 s at the middle power level,determination wavelength of 765 nm.The standard curve exhibited a good linear relationship between absorbance and gallic acid concentration from 1 to 50 mg/L（R2 = 0.9996）.When several gallic acid solutions were added to grape and grape wine samples,the average recovery rates of spiked gallic acid in grape and grape wine samples were 98.1% and 97.2%,respectively,with a relative standard deviation（RSD） ranging from 1.40% to 1.01%.This new method is characteristic of simple operation,fast determination,excellent precision,prefect reproducibility and significant reduction in the consumption of samples,reagents as well as time.Therefore,this new method is a promising method for determining total polyphenol in grape and grape wine.