Abstract: This study was carried out in order to investigate the effect of exogenous ethpheon treatment of grapes on the phenolic composition of wine. In a small container, wine was fermented from Cabernet Sauvignon (Vitis vinifera L.) grape berries sprayed with 400 mg/L ethophen (containing 1 mL/L Tween-80) or Tween-80 as a control at the beginning of veraison and harvested at the optimal time. The phenolic composition of the wine was qualitatively and quantitatively detected by high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-MS/ESI). The results showed that exogenous ethophen effectively increased the chroma and color hue values of the wine, the total concentration of anthocyanins and the concentrations of most individual anthocyanins, the prominent ones being malvidin-3-O-glucoside and malvidin-3-O-(6-O-acetyl)-glucoside. Meanwhile, the concentrations of most individual non-anthocyanin phenolics, the major ones being epicatechin and gallic acid, and the total concentration of non-anthocyanin phenolics were also significantly increased. On the other hand, the concentrations of cyanidin-3-O-(6-O-acetyl)-glucoside, cyanidin-3-O-(trans-6-O-coumaryl)-glucoside and salicylic acid in the wine were not affected by exogenous ethophen treatment. Partial least squares discriminant analysis (PLS-DA) showed that the phenolic composition significantly differed between the treatment and control groups, and the anthocyanins malvidin-3-O-glucoside, malvidin-3-O-(6-O-acetyl)-glucoside and petunidin-3-O-(6-O-acetyl)-glucoside and the hydroxybenzoic acid gallic acid were the major differential phenolic components between the two groups, greatly contributing to the treatment group. In addition, exogenous ethophen increased the ratios of 3’5’/3’-hydroxyl subtituted methoxylated/non-methoxylated and pyrano/non-pyrano-anthocyanins, and decreased the ratios of 3’5’/3’-hydroxyl subtituted flavanols and 3’5’/3’-hydroxyl subtituted flavonols in the wine. In summary, treatment of wine grapes with exogenous ethophen in the fields plays a positive role in the accumulations of anthocyanin and non-anthocyanin phenolics in wine, and is therefore useful for the cultivation of ‘Cabernet Sauvignon’ grapes.

Key words: ethophen; phenolic composition; ‘Cabernet Sauvignon’; wine