Briedis Vitalis, Povilaityte Vitalija, Kazlauskas Saulius, Venskutonis Petras Rimantas
Department of Drug Technology and Pharmaceutical Management, Kaunas University of Medicine, Kaunas, Lithuania.
Medicina (Kaunas). 2003;39 Suppl 2:104-12.
The objective of this study was to produce grape (Vitis vinifera L.) extracts using efficient solvents and to compare antioxidant activity, polyphenol and anthocyanin content and composition in the produced extracts to the same characteristics of grape juices and wines. Methanolic and aqueous extracts of red and blue grapes were produced. Total amounts of polyphenols and anthocyanins in grape extracts, juices and wines were determined. Total polyphenols were spectrophotometrically determined measuring absorption after using Folin-Ciocalteau reagent. Total anthocyanins were determined by pH-differential method. Antioxidant activity of all those grape products was analyzed in 2,2-diphenyl-1-picrylhydrazil (DPPH) and 2,2'-azine-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical binding model systems. The results obtained by both antioxidant activity determination methods were comparable and permitted to evaluate the ability to inactivate free radicals. Individual polyphenols and anthocyanins were separated by high performance liquid chromatography. Compounds of malvidine, delphinidine and petunidine were identified as main anthocyanins present in grape products demonstrating antioxidant activity. The determined amounts of polyphenols and anthocyanins in red wines were relatively higher than in other investigated objects. The wines possessed the highest antioxidant activity, which correlated with the determined amounts of total polyphenols. Correlation between total anthocyanins contents and antioxidant activity of appropriate objects was not established.
本研究的目的是使用高效溶剂制备葡萄（Vitis vinifera L.）提取物，并将所制备提取物中的抗氧化活性、多酚和花青素含量及组成与葡萄汁和葡萄酒的相同特性进行比较。制备了红葡萄和蓝葡萄的甲醇提取物和水提取物。测定了葡萄提取物、葡萄汁和葡萄酒中多酚和花青素的总量。使用福林-西奥尔特试剂后，通过分光光度法测定总多酚的吸光度来确定其含量。总花青素通过pH差值法测定。在2,2-二苯基-1-苦基肼（DPPH）和2,2'-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）（ABTS）自由基结合模型系统中分析了所有这些葡萄产品的抗氧化活性。两种抗氧化活性测定方法得到的结果具有可比性，能够评估使自由基失活的能力。通过高效液相色谱法分离了单个多酚和花青素。鉴定出锦葵色素、飞燕草色素和矮牵牛色素的化合物是葡萄产品中具有抗氧化活性的主要花青素。红葡萄酒中测定的多酚和花青素含量相对高于其他被研究对象。葡萄酒具有最高的抗氧化活性，这与测定的总多酚含量相关。未确定适当对象的总花青素含量与抗氧化活性之间的相关性。
