酶法酯交换制备食品专用油脂的研究

Synthesis of Interesterification Special Oils by Enzymatic Catalysis

以牛油、茶籽油和棕榈硬脂为基本原料,通过特异性固定化脂肪酶Lipozyme RM IM催化制备零反式脂肪酸食品专用油脂基料油。在单因素试验基础上进行Box-Behnken响应面试验设计,考查了底物比、酶添加量、反应时间和反应温度对产物滑动熔点的影响,建立了响应面回归模型,确定了酶催化酯交换反应的最优条件为底物比7.55∶2.45∶4.00(牛油∶茶籽油∶棕榈硬脂),酶添加量3.65%,反应时间3.85 h,反应温度72.6℃,所得产物滑动熔点为36.8℃,与理论值37℃接近,误差<1%,与酯交换反应前相比,经酯交换反应后产物油脂的固体脂肪指数降低,可作为良好的替代氢化油的人造奶油基料油。

The interesterified oil with trans-free fatty acid were synthesized by interesterification of beef tallow, camellia oil and palm stearin using specific immobilized lipase Lipozyme RM IM. The Box-Behnken response surface experiment was designed on the basis of single factor experiments. The effects of substrate ratio, enzyme concentration, reaction time, and reaction temperature on the sliding melting point were investigated. A response surface regression model was established to determine the optimum conditions for the enzymatic interesterification were as follows： the ratio of substrate was 7.55 ： 2.45 ： 4.00 （beef tallow ： camellia oil ： palm stearin）, in the concentration of 3.65% Lipozyme RM IM, reaction 3.85 h at 72.6 ℃. Under these condition, the sliding melting point was 36.8 ℃, which is close to the theoretical value of 37 ℃ and the error was less than 1%. In addition, the solid fat index of interesterified oil was greatly reduced as compared with blend oil demonstrate that it could be utilized as a good substitute for hydrogenated oil in food industry.