国家重点研发计划项目(2016YFD0400802)，人才培养质量建设--一流的专业建设 (PXM2019-014213-000010)，基本科研业务费( PXM2019-014213-000007).
1.Beijing Engineering and Technology Research Center of Food Additives， Beijing Technology and Business University;2.R&D Center of China Tobacco Yunnan Industrial Co.，Ltd.;3.Beijing Engineering and Technology Research Center of Food Additives，Beijing Technology and Business University;4.Beijing Engineering and Technology Research Center of Food Additives;5.Zhongda Hengyuan Biotech Co., Ltd.
研究了非水相体系中杂醇油酶转化酯香料的影响因素,筛选适宜脂肪酶,优化其酶转化条件,研究超声场强对酶转化酯香料的作用。结果表明,在无溶剂体系中固定化脂肪酶Novozym 435 FG的酯化活力高,且便于回收再利用,其乙酸异戊酯产率达到92.62%；除水剂分子筛的加入促进了酯化反应,乙酸加入次数和间隔时间、反应温度和时间、摇床转速及超声场强对酯香料产率有一定影响；正交设计试验优化条件为：1.5 ml乙酸分6次加入、间隔时间3h、反应时间36h、分子筛添加量2g、杂醇油3ml、脂肪酶加入量70mg、温度45℃、转速140r/min,其乙酸异戊酯、乙酸异丁酯、乙酸正丙酯的产率分别达到89.2±0.7(%)、89.3±0.6(%)、76.8±0.9(%)。在超声功率50Hz、超声频率0.5 W/cm2处理6h时酯香料产率达到85%以上,显著高于摇床组的酯产率15%,说明适当超声处理可大大加速反应进程,显著缩短反应时间,但超声处理的酯香料最终产量和产率未见增加；长时间超声空化作用造成体系微环境改变,降低了固定化酶的稳定性和使用次数。
The influence factors of ester aromas with lipase-catalyzed of fusel oil in non-aqueous media system were studied,screening suitable lipase, optimizing the conditions of enzyme conversion,the effect of ultrasonic field intensity on enzyme conversion was studied. The results showed that the esterification activity of immobilized lipase Novozym 435 FG was high and easy to recycle, the yield of isoamyl acetate was 92.62%; The addition of dehydrating agent molecular sieve promoted the esterification reaction, The ester yield rates were affected on added times,time interval of acetic acid, shaker speed, reaction temperature,reaction time and ultrasonic field intensity; Optimized conditions by orthogonal test design were as follows: 1.5ml acetic acid was added in six times, the interval time was 3h, the reaction time was 36h, the molecular sieve was 2g, the fusel oil was 3ml, the lipase was 70mg, the reaction temperature was 45℃, the shaker speed was 140r/min, the yield of isoamyl acetate, isobutyl acetate and propyl acetate reached 89.2±0.7 (%), 89.3±0.6 (%) and 76.8±0.9 (%), respectively. At the ultrasonic power of 50Hz and ultrasonic frequency of 0.5w/cm2 for 6h, the ester yield reached more than 85%, which was significantly higher than the ester yield of the shaking group of 15%, it indicates that proper ultrasonic treatment can greatly accelerate the reaction process and shorten the reaction time, however, the final yield and yield of ultrasonic treated did not increase, ultrasonic cavitation for a long time can change the microenvironment of the system and reduce the frequency and stability of immobilized enzyme.