有机酸含量对葡萄酒发酵的影响

为了考察有机酸含量对葡萄酒发酵的影响，在初始有机酸含量分别为4 g/L、7 g/L和10 g/L的模拟葡萄汁中接种酵母，于25℃发酵，比较不同初始有机酸含量对葡萄酒发酵过程中酵母生长、降糖、有机酸及挥发性化合物含量的影响。结果表明，初始有机酸含量7 g/L时酵母生长和耗糖最慢，乙醇和乙醛产生量最低；随初始有机酸含量升高，pH值、酒石酸、苹果酸、乳酸、乙酸、总酸、乙酸乙酯和总酯含量呈下降趋势；琥珀酸、正丙醇、异丁醇、异戊醇及总高级醇含量呈上升趋势；但对β-苯乙醇、正丁醇及丁酸乙酯含量影响较小。初始有机酸含量10 g/L的葡萄酒发酵过程酵母生长快、降糖最快，产酸含量适中，同时香气较好。因此，葡萄酒发酵的适宜初始有机酸含量为10 g/L。

Effects of organic acids content on the fermentation of wine

In order to investigate the effect of organic acid content on wine fermentation, the wine fermentation was performed at 25 ℃ by inoculating yeast in the simulated grape juice with initial organic acids concentration of 4 g/L, 7 g/L and 10 g/L, respectively. The effects of different initial organic acids contents on yeast growth, sugar consumption, contents of organic acids and volatile compounds in wine fermentation process were compared. The results showed that the yeast growth, sugar consumption, the production of ethanol and acetaldehyde was the lowest at the initial organic acids concentration of 7 g/L. With the increase of initial organic acids concentration, the pH, the content of tartaric acid, malic acid, lactic acid, acetic acid, total acid, ethyl acetate and total ester decreased, while succinic acid, n-propanol, isobutyl alcohol, isoamyl alcohol and total higher alcohol increased. However, the initial organic acids concentration had little effect on the production of β-phenyl ethanol, n-butanol and ethyl butyrate. The wine fermentation at the initial organic acids concentration of 10 g/L showed the fastest yeast growth and sugar consumption, moderate organic acid productivity and proper aroma quality. Therefore, the optimal initial organic acids concentration for wine fermentation was 10 g/L.