Effects of Tannin Addition on Changes in Color and Anthocyanin Content of Cabernet sauvignon Wine and Their Correlation

To investigate the impact of distinct wine tannins on the color and anthocyanin composition of wine, Cabernet sauvignon was employed as the primary ingredient for the production of wine using five distinct wine tannins. The wine was then aged for 120 days. The study involved the detection and analysis of various components of wine, including total phenols, total anthocyanins, total flavanols, monomer anthocyanins, chromaticity, and sensory evaluation, throughout the process of fermentation and aging. The findings indicated that the introduction of tannin prior to alcohol fermentation might lead to a rise in the overall phenolic composition of wine, exert an influence on its color, and enhance its gustatory attributes. The BSO group (oak tannin) exhibited a conspicuous elevation in the overall phenol content, with the maximum value reaching 1850.13 mg/L. Following a 120 d aging period, it was observed that the BRE group (comprised of green tea tannin) exhibited a significantly higher b^* value, indicating a yellow tone, in comparison to the other experimental groups. Additionally, the color of the BRE group was noted to be yellowish brown. Following a 120 d aging period, the a^* values of the PTZ (grape seed tannin) and ECA (chestnut tannin) groups exhibited a significant increase in red tone, with a respective increase of 38.19% and 27.76% compared to the aged control group that did not contain tannin. Additionally, the colors of the tannin groups were observed to be more stable and purplish red. The findings of the correlation collinear network analysis indicated a positive correlation between the red color of wine and a majority of monomer anthocyanins (P<0.05, |r|>0.6). Additionally, a negative correlation was observed between the red color of wine and certain acylated anthocyanins (namely, acetylated dimethyl alexin-3-O-glucoside, alexin-3-O-acetylated glucoside, and coumarin acylated 3'-methyl alexin-3-O-) (P<0.05, |r|>0.6). In conclusion, the character of red wine could be enhanced more effectively by adding wine tannins prior to fermentation, condensed tannins derived from grape seeds produced the most effective auxiliary color.