ZHONG Ke, XIAO Jian, TANG Xiaohong, DING Yan, LI Zhiyu, LI Ruirui, HAN Xiaomei, SUN Yuxia
In this study, non-Saccharomyces cerevisiae with strong fermentation ability, excellent aroma production and high tolerance were isolated and screened from the natural fermentation broth of navel orange in Fengjie. Navel orange wine was prepared by mixed fermentation with commercial S. cerevisiae BV818, and its brewing characteristics were evaluated. The results showed that a total of 15 strains of non-Saccharomyces cerevisiae were isolated and screened, numbered as A1-A15, and 2 excellent strains A1 and A2 were screened according to fermentation ability and aroma production ability. Strains A1 and A2 were identified as Starmerella bacillaris and Pichia kluyveri, respectively. Strain A1 could tolerate glucose 500 g/L, fructose 500 g/L and ethanol 14%, strain A2 could tolerate glucose 400 g/L, fructose 400 g/L and ethanol 12%, strains A1 and A2 could tolerate KCl 1.2 mol/L, SO2 500 mg/L, temperature 12-38 ℃, and pH 3. A total of 35 aroma compounds were detected in navel orange wines prepared by fermentation of strain A1 and A2 mixed with strain BV818 (10∶1, V/V), respectively and 11 key aroma compounds (OAV>1) were selected based on aroma activity value (OAV). The total esters contents of navel orange wine fermented by mixing strain A1 and strain BV818 was increased by 177.95%. Total phenols, total flavonoids, glycerol contents, sensory score, ascorbic acid, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals scavenging rate were the highest, which were 487.92 mg/L, 565.88 mg/L, 7.39 g/L, 84.54 points, 642.31 mg/L and 86.85%, respectively. In conclusion, strain A1 had the potential to be used in navel orange wine industry.
