Analysis of Phenolic Compounds and Antioxidant Properties of Wines from Three Wine Grape-Growing Regions in China

Abstract

In order to optimize two methods for the determination of antioxidant activity and compare the phenolic compounds (total phenols, total flavonoids, total flavanols and total anthocyanins) and antioxidant properties of the main wine grape varieties cultivated in three regions in China. The antioxidant activities of wines were measured by two different analytical assays: 2, 2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH+), the optimal reaction conditions of each method were also determined. Results showed that the dilution multiple of 0.15:10~0.2:10 and the reaction time of 200~240min were the optimal reaction condition for ABTS method. For DPPH method, the reaction time of 90~110 min and the dilution multiple of 0.4:10~0.8:10 were selected. Among the varieties tested, the contents of phenolic compounds and antioxidant activities in Cabernet Sauvignon wine from Ningxia and Xinjiang region were significantly higher than others, followed by the Merlot from Ningxia region. These parameters were the lowest in Cabernet Gernischet and Pinot Noir wines from Yantai and Xinjiang region, respectively. The phenolic contents and antioxidant capacity of four single varietal wines in the Ningxia region were in a higher value than in Yantai and Xinjiang region. In addition, a close relationship between phenolic contents and antioxidant capacity was observed. Analysis showed that the contents of phenolic compounds and the levels of antioxidant activity in the wine samples greatly varied with cultivar and environmental factors among regions of wine growth.