脂肪酶对白酒四大酯的可逆合成与分解

Reversible synthesis and hydrolysis of four main esters in Chinese liquor catalyzed by lipase

为了探究白酒中四大酯的可逆合成与分解规律,用固定化南极假丝酵母脂肪酶B(Novozym 435),分别在水相和有机相(正己烷)中,进行酯化反应。结果显示,4种酯在水相中有利于分解,分解转化率为乙酸乙酯>丁酸乙酯>乳酸乙酯>己酸乙酯,在有机相(正己烷)中有利于合成,合成转化率为己酸乙酯>丁酸乙酯>乳酸乙酯>乙酸乙酯。同时重点比较了酯在水相中的合成能力,测得酯在水相中5 h内的最高合成转化率分别为乙酸乙酯8.9%、丁酸乙酯29.1%、己酸乙酯16.7%、乳酸乙酯5.7%,低于水相中的水解转化率和有机相中的合成转化率。研究结果对白酒风味酯的形成原理以及生产合成具有参考价值。

This research aimed to study reversible synthesis and hydrolysis of four main esters in Chinese liquor. Esterification in aqueous phase and organic phase were conducted using Novozym 435. The results showed that four main esters prefer hydrolysis than synthesis in aqueous phase while they prefer synthesis in organic phase. The hydrolysis rate of the four main esters in aqueous phase ranked in descending order as ethyl acetate〉ethyl butyrate〉ethyl lactate〉ethyl hexanoate. While the synthesis rate in organic phase ranked in decreasing order as ethyl hexanoate〉ethyl butyrate〉ethyl lactate〉ethyl acetate. The synthesis of esters in aqueous phase was compared. The highest synthesis rate of ethyl acetate, ethyl butyrate, ethyl hexanoate and ethyl lactate in aqueous phase were 8.9%, 29.1%, 16.7% and 5.7%, respectively, which is lower than hydrolysis rate in aqueous phase and synthesis rate in organic phase. These results are valuable for the understanding of flavor ester synthesis and their production in Chinese liquor.