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The purpose of this study was to examine the changes in the contents of sugar, ethanol, organic acids, volatile compounds, pH and acidity in sugarcane wine during fermentation using Saccharomyces cerevisiae and the consumer preference test was also conducted to investigate the optimal fermentation. According to the results, the maximal population of S. cerevisiae reached to 8.12 log cfu/mL at the sixth day of fermentation. The maximum ethanol content, 15.16%, was obtained at the ninth day, while the sucrose and glucose concentrations were almost exhausted at the same time. As for organic acids, citric acid was detected as the most abundant one at the second day of fermentation, followed by lactic and succinic acids. The volatile compounds were analyzed by SPME/GC‐MS, and the concentrations of alcohols, esters and acids were all highest in sugarcane wine at the sixth day of fermentation. The results have demonstrated that sugarcane wine fermentation with S. cerevisiae at the sixth day is enough to reach the highest aroma quality as indicated by the highest esters/alcohols in the wine and the most abundant amount of aroma‐related compounds. The overall preference of consumer test also supports the above result with the sugarcane wine fermented at day 6 having highest scores. PRACTICAL APPLICATIONS Sugarcane with high content of sugar is a potential material for making vinegar through alcoholic and acetous fermentation. Because the sugarcane wine as well as sugarcane vinegar is seldom available in Taiwan or other places, it is beneficial to study how to effectively use the sugarcane other than just consumed as a kind of fresh fruit or a juice drink. The economic value of wine is highly depended on its composition changes and consumer's preference. Although there are a few reports working on the chemical compounds during fermentation of sugarcane wine, there is little concerning the consumer‐type preference parallel to the chemical analysis during fermentation. Following the identification of winemaking fermenting yeast strain, Saccharomyces cerevisiae, isolated from liquor rice dregs and the establishment of the fermenting condition for making sugarcane wine carried out in our previous studies, in this study, we analyzed the composition of volatile compounds in sugarcane wine and characterized the associated changes in chemical properties during fermentation. In addition, the consumer preference test was also carried out to verify the results of chemical property analysis. It is hoped the strategy of this study to be a reference prior to industry scale for manufacturing process and quality improvement of sugarcane wine and other wines.

The purpose of this study was to investigate the effects of alcoholic fermenting conditions such as sugar content, fermentation temperature and pH on the sensory quality and ethanol content of sugarcane wine (SCW) by response surface methodology. The results from contour plots showed that the maximum ethanol content was around 11% with the initial sugar content at 25.0°Brix, and fermentation at 26.3C and pH 5.5. The results of consumer tests showed that under the fermentation condition with sugar content at 24°Brix or below and higher temperature favored the color acceptance of SCW. While the sugar content above 24°Brix, the lower temperature favored the aroma, flavor and overall preference. Statistical analysis with the central composite rotatable design showed that the total soluble solids of SCW was 5 Corresponding 330 significantly (P < 0.05) correlated with sugar content, pH and fermentation temperature. The sugar content and fermentation temperature significantly (P < 0.05) affected the ethanol content and aroma of SCW, while the pH significantly (P < 0.05) affected the flavor and overall preference. Based on the results of total soluble solids, ethanol contents, consumer tests and confirmative experiments, it was determined that the sugar content at 24-26°Brix, pH at 5.5 and fermentation temperature at 24-27C were the optimal fermentation conditions for SCW. PRACTICAL APPLICATIONSSugarcane with high content of sugar is a potential material for making vinegar through alcoholic and acetous fermentation. Sugarcane wine (SCW), as well as sugarcane vinegar, is seldom available in Taiwan or in other places. It is beneficial to study how to effectively improve the use of sugarcanes other than just consumed as a kind of fresh fruit or a juice drink. The economic value of wine is highly dependent on its sensory quality and consumer's preference. This study evaluated the fermentation conditions including the sugar content, pH and fermentation temperature affecting the quality and consumer's preference of SCW in order to establish the optimum processing condition for SCW. It is suggested to be the reference for manufacturing process in wine industry. In addition, it can also provide a versatile utility of raw material and value added to final products. FERMENTING CONDITIONS FOR SUGARCANE WINE