T1脂肪酶催化合成甘油酯过程中MAG与DAG最大含量预测模型研究

Empirical Model for Predicting Contents of Monoglyceride and Diglyceride during the Synthesis of Acyglycerols by T1 Lipase-Catalyzed Esterification

摘要:

单甘酯（MAG）和甘油二酯（DAG）作为一类多功能添加剂，广泛应用于食品和化妆品等行业。本文利用T1脂肪酶催化甘油和油酸酯化反应合成甘油酯，探讨了底物摩尔比、水添加量、反应时间和温度对产物MAG和DAG含量的影响。结果表明，MAG含量随着反应时间的进行呈现先增大后缓慢减少的趋势，DAG含量则随着时间的进行先快速增大后趋于平衡的趋势，甘油三酯呈现不断增加的趋势。在给定温度范围内（40~60 ℃），温度对DAG和MAG含量影响可忽略不计。基于该过程摩尔比和水添加量的影响，建立了MAG和DAG含量变化规律的预测模型，ErDAG%=0.5967×r0.271×(–1.01Dw +40.2)，ErMAG%=0.7422×r0.366×(-0.745 Dw +23.7)，实验实测值与模型预测值之间相近程度的曲线拟合相关系数（R2）均达到0.99以上。可见，在本实验范围下，该模型可有效预测反应过程DAG和MAG最大含量的变化规律。本模型将为T1脂肪酶催化合成甘油酯过程中MAG和DAG最大含量变化的生产实践提供很好的指导。

Abstract:

Monoglyceride (MAG) and diglyceride (DAG) are a kind of multifunctional additives. They are widely used in food and cosmetic industries. Acylglycerols are synthesized by esterification of glycerol with oleic acid in the presence of T1 lipase. The effects of substrate molar ratio (glycerol: oleic acid), water content, time and temperature on esterification progress were studied. An empirical model for predicting MAG and DAG contents during the synthesis of acylglycerols was proposed. The results showed that MAG content increased first and then slowly decreased with an increase of reaction time, DAG content increased rapidly first and tended to stable during the time increased, while triglyceride (TAG) content exhibited a keep increasing pattern. MAG and DAG contents were hardly influenced by reaction temperature ranging from 40–60 oC. Based on the effects of substrate molar ratio and water content, two empirical models [ErDAG% = 0.5967 × r0.271 × (–1.01Dw + 40.2) and ErMAG% = 0.7422 × r0.366 × (–0.745Dw + 23.7)] were established for predicting MAG and DAG contents, respectively. The results showed that the present models had a good correlation (R2 = 0.99) with the experimental data for predicting MAG and DAG contents. Such data would be valuable for the process control and optimization of the synthesis of acylglycerols.