高乳酸乙酯酯化液的制备及其在调味酒生产中的应用

该研究利用筛选自老白干酒醅中的一株高产乳酸干酪乳杆菌（Lactobacillus casei）发酵制得乳酸发酵液，通过南极假丝酵母（Candida antarctic）脂肪酶B催化乳酸发酵液与酒尾合成乳酸乙酯，并通过单因素试验和正交试验对其催化工艺进行优化，最后通过蒸馏浓缩得到乳酸乙酯调味酒。结果表明，乳酸乙酯合成最佳催化工艺为：酒精度40%vol的酒尾与乳酸发酵液体积比1∶1，pH值3.0，酯化酶添加量0.5%，反应温度30 ℃，反应时间21 d。在此最优催化工艺下，酯化液中乳酸乙酯含量达12.05 g/L。将其浓缩后得到乳酸乙酯含量为17.62 g/L的调味酒（酒精度45%vol），其清澈透明，酯香突出，适用于勾调冬季或机械化生产中乳酸乙酯含量偏低的基酒，增加酯含量，提升酒的品质。

Preparation of esterification solution with high ethyl lactate content and its application in the production of flavoring liquor

In this study, the lactic acid fermentation broth was prepared by high yield lactic acid Lactobacillus casei screened from Laobaigan fermented grains, and the ethyl lactate was synthesized from lactic acid fermentation broth and tailing liquor catalyzed by Candida antarctic lipase B. The catalysis process was optimized by single factor tests and orthogonal tests, and the ethyl lactate flavoring liquor was obtained by distillation and concentration. The results showed that the optimum catalysis process for the synthesis of ethyl lactate was as follows: the volume ratio of tailing liquor with alcohol content 40%vol to lactic acid fermentation broth 1∶1, pH 3.0, esterase addition 0.5%, reaction temperature 30 ℃, and time 21 d. Under the optimum catalysis process, the content of ethyl lactate in the esterification solution reached 12.05 g/L. The flavoring liquor with ethyl lactate content of 17.62 g/L (alcohol content 45%vol) was obtained after concentration, which was clear and transparent, with prominent ester aroma, and was suitable for blending base liquor with low ethyl lactate content in winter or mechanized production to increase ester content and improve liquor quality.