Optimization of fermentation conditions and comparison of flavor compounds for three fermented greengage wines

Greengage wine is a popular alcoholic beverage that is consumed in China, Korea, and Japan. The main objective of this study was to optimize the fermentation conditions and compare the flavor compounds for three fermented greengage wines (Optimized sample, Wuliangye, and Choya). The relevant parameters of greengage wine were optimized using response surface methodology and central composite design experiments by studying the individual and interactive effects of three variables, including fermentation temperature, material-liquid ratio, and sugar content. The results demonstrated that second-order polynomial models could predict and describe the biochemical responses of alcohol content (P < 0.0001) and sensory evaluation (P < 0.001). The optimized conditions (fermentation temperature, material-liquid ratio, and sugar content) for fermented greengage wine were 20 °C, 1:2.0, and 180 g/L, respectively. According to the statistical analysis, there were significant differences of flavor compounds and their concentrations in three fermented greengage wines (p < 0.05). A total of 53, 30, and 32 flavor compounds were identified in the Optimized sample, Wuliangye, and Choya, respectively. Among these compounds, 5, 2, and 3 quantified compounds (odor activity values > 1) can be found in three fermented greengage wines, and they probably contribute to the wine aroma.