JIA-2018-09

2131 WANG Ying et al. Journal of Integrative Agriculture 2018, 17(9): 2126–2136 very interesting phenomena. 3.5. Effects of fermentation conditions on growth dynamics of Hmp-1 and FM-S-115 As shown in Table 1, the growth of Hmp-1 was seriously inhibited with the increase of ethanol concentrations. When the ethanol concentration was 10% (v/v), the growth of Hmp-1 was completely inhibited. By contrast, S . cerevisiae FM-S-115 was still able to proliferate when the ethanol concentration was 14% (v/v). Those results could suggest that Hmp-1 was more sensitive to high concentration ethanol, and its growth would be controlled through increasing ethanol concentration during wine storage. The effects of SO 2 in different concentrations on the growth dynamics of Hmp-1 and FM-S-115 were presented in Table 2. We found that Hmp-1 was more sensitive to SO 2 than FM-S-115 based on their growth. When SO 2 concentration was 50 mg L –1 , the growth of Hmp-1 was completely inhibited. By contrast, the counts of FM- S-115 were not obviously affected under different SO 2 concentration conditions (25–125 mg L –1 ) at the same fermentation time at P >0.05. The effects of sugar in different concentrations on growth dynamics of Hmp-1 and FM-S-115 were presented in Table 3. We observed that the growth of FM-S-115 were not significantly affected under different sugar concentration conditions (10–25%, w/v) at the same fermentation time at P >0.05. However, the growth of Hmp-1 was obviously inhibited when the sugar concentration was 25% (w/v). The results showed that Hmp-1 had lower resistance to high concentration of sugar compared to FM-S-115. As shown in Table 4, the growth of Hmp-1 and FM-S-115 was all very slowly at 15°C. The viable count of Hmp-1 was 6.55 (Log 10 CFU mL –1 ), and that of FM-S-115 reached to 6.79 (Log 10 CFU mL –1 ) on the 10th d, respectively. But in general, the cell densities of Hmp-1 and FM-S-115 were increased when the fermentation temperature increased from 15 to 30°C. The growth of Hmp-1 was obviously inhibited when the fermentation temperature was 35°C ( P <0.05). 3.6. Effect of Hmp-1 on volatile compounds of black- berry wine The volatile compounds are important components of the flavor substances in blackberry wine. In this study, 34 kinds of volatile compounds had been detected in the blackberry wine fermented by FM-S-115, and 28 kinds of volatile compounds had been detected in the Table 1 Effects of ethanol in different concentrations on the growth dynamics of Pichia membranifaciens Hmp-1 and Saccharomyces cerevisiae FM-S-115 (Log 10 CFU mL –1 ) during fermentation Fermentation time (d) Stain Ethanol concentration (v/v, %) 8 10 12 14 1 FM-S-115 6.54±0.31 6.49±0.35 6.39±0.31 6.14±0.45 Hmp-1 6.14±0.33 – – – 5 FM-S-115 7.78±0.53 a 7.71±0.44 a 7.65±0.25 a 7.05±0.51 b Hmp-1 6.52±0.46 – – – 10 FM-S-115 7.56±0.47 a 7.52±0.51 a 7.47±0.61 a 7.26±0.33 b Hmp-1 7.05±0.31 – – – Total yeast numbers are expressed as the mean values±SD. Different letters within each row mean significant differences ( P <0.05). –, undetected. Table 2 Effects of SO 2 in different concentrations on the growth dynamics of Pichia membranifaciens Hmp-1 and Saccharomyces cerevisiae FM-S-115 (Log 10 CFU mL –1 ) during fermentation Fermentation time (d) Stain Free SO 2 concentration (mg L –1 ) 25 50 75 100 125 1 FM-S-115 6.57±0.19 a 6.54±0.15 a 6.57±0.21 a 6.51±0.37 a 6.15±0.37 b Hmp-1 6.34±0.35 a 3.26±0.41 b – – – 5 FM-S-115 7.85±0.44 a 7.83±0.33 a 7.81±0.41 a 7.76±0.51 a 7.56±0.58 b Hmp-1 6.82±0.26 – – – – 10 FM-S-115 7.54±0.34 7.66±0.26 7.56±0.50 7.57±0.38 7.48±0.67 Hmp-1 7.17±0.22 – – – – Total yeast numbers are expressed as the mean values±SD. Different letters within each row mean significant differences ( P <0.05). –, undetected.