Karvela Evangelia, Makris Dimitris P, Kalogeropoulos Nick, Karathanos Vaios T
Department of Science of Dietetics-Nutrition, Harokopio University, Athens, Greece.
Talanta. 2009 Oct 15;79(5):1311-21. doi: 10.1016/j.talanta.2009.05.042. Epub 2009 Jun 6.
A 2(3)-full factorial design and response surface methodology were deployed to assess some basic factors (time, % ethanol and pH) affecting profoundly the extractability of polyphenolic phytochemicals from grape (Vitis vinifera) stems. In an effort to obtain a thorough insight into the applicability of the models established, stem extracts from three different varieties were tested, by determining several indices of the polyphenolic composition, such as total polyphenol (TP), total flavanol (TFl), total flavone (TFn) and proanthocyanidin (PC) concentration. It was shown that the models generated can adequately predict the recovery levels for each polyphenol group, but the optimal conditions predicted for TP, TFl, TFn and PC recovery varied significantly. Notable differences were also seen among the different varieties. Correlation of the polyphenol indices with the antiradical activity and reducing power of the extracts indicated that the PC fraction might exert strong effects, while the influence of other groups was not apparent. Examination of the optimally obtained extracts using liquid chromatography-mass spectrometry revealed that the most prominent compounds were caftaric acid, flavanols and derivatives thereof, as well as dehydroflavonols and flavonols.
采用2(3)全因子设计和响应面方法，评估了对葡萄（欧亚种）茎中多酚类植物化学物质提取率有深远影响的一些基本因素（时间、乙醇百分比和pH值）。为了深入了解所建立模型的适用性，通过测定多酚组成的几个指标，如总多酚（TP）、总黄烷醇（TFl）、总黄酮（TFn）和原花青素（PC）浓度，对来自三个不同品种的茎提取物进行了测试。结果表明，所生成的模型能够充分预测每个多酚组的回收率，但预测的TP、TFl、TFn和PC回收率的最佳条件差异显著。不同品种之间也存在显著差异。多酚指标与提取物的抗自由基活性和还原能力的相关性表明，PC组分可能发挥强大作用，而其他组的影响不明显。使用液相色谱-质谱联用仪对最佳提取得到的提取物进行检测，结果显示最主要的化合物是咖啡酸、黄烷醇及其衍生物，以及脱氢黄酮醇和黄酮醇。
