Effect of solid or liquid fermentation state, yeast strain, fermentation temperature and time on the flavor content of jujube (Ziziphus jujuba) brandy

Abstract

Background: Jujube brandy is characteristic distilled fruit liquor in China, which lack mature production technology until now. Materials and Methods: The conditions of fermentation way (solid and liquid state), starter culture (single-yeast, mixed-yeast and jiuqu), fermentation temperature (15,18, 23, 28, 32) and fermentation time (6,10,14, 20, 24, 28 days) were optimized based on one-factor tests and Response Surface Methodology (RSM). Results: From one factor flavor content result, solid state fermentation (K-3790.63, J-3250.22, DK-3553.64 mg L-1) was about 8 times of liquid state fermentation (Z, W). Jujube brandy fermented with single-yeast GH and PH have the best flavor (4232.64, 4125.46 mg L-1, respectively), followed by mixed-yeast PHGHSX and GHSX, J Jiuqu has the worst (1670.48 mg L-1). Flavor content increased with temperature rising before 28, reach the peak at 28 (3790.63 mg L-1), then decreased. At 20 and 24 days, jujube brandy got the better flavor (4442.71, 4303.66 mg L-1), significantly higher than 6 days (3790.63) and 28 days (2373.71 mg L-1). Conclusions: Combined with RSM result, the optimal conditions of brewing were: Choosing solid-state fermentation, yeast GH (Saccharomyces cerevisia cctcc-M94055), fermentation temperature of 18°C, fermentation time of 24 days and the content of flavor compounds was 4525.934 mg L-1, which is 1.19 times of normal brewing, almost accords with the predicted data, has great practical values.