Investigation of fermenting conditions for sugarcane (saccharum officinarum l.) wine using response surface methodology

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 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. Sugarcane 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.