SU Hao, LIN Mei, REN Xiangyun, LIANG Zhangcheng, XU Jinglan, XU Changyi, LI Weixin
To enhance the quality of Vitis davidii wine, using Ziqiu grape as the raw material and Saccharomyces cerevisiae JP2 as the fermentation strain, the V. davidii wine was prepared using a juice-separated (saignee) fermentation method, and the effects of different juice separation ratios (0%, 10%, 15%, 20%, 25%, 30%, 35%) on the basic physicochemical indicators, phenolic compounds, sensory quality, and volatile flavor components of wine were investigated. The results indicated that the optimal juice-separated ratio for V. davidii wine fermentation was 30%. Under the condition, the total sugar content of wine was 3.52 g/L, the total acid content was 7.67 g/L, and the alcohol content was 12.70%, classifying it as a dry red wine. Compared to wine produced without juice separation, the total phenol, proanthocyanidin, anthocyanin, total flavonoid, and tannin contents increased by 28.02%, 81.65%, 66.38%, 47.75%, and 208.68%, respectively. Both red and yellow chroma increased, resulting in higher color saturation and a larger color difference, presenting a brick red color. The aroma became more intense, and the wine body and taste were more harmonious. The contents of esters, alcohols, acids, aldehydes and ketones, and other substances increased by 37.86%, 9.45%, 7.92%, 44.14%, and 135.77%, respectively. There were 12 volatile aroma compounds with an odor activity value (OAV) > 1, among which ethyl caproate, isoamyl acetate, ethyl caprylate, ethyl decanoate, and eugenol were all present in higher concentrations in wine produced with juice separation 30% than the juice without separation. In summary, juice-separated fermentation can enhance the quality of Ziqiu grape wine.
