无溶剂体系酶催化油酸淀粉酯的合成

Lipase-Catalyzed Esterification of Starch Using Oleic Acid in Solvent-Free System

以玉米淀粉和油酸为原料,研究了无溶剂体系下油酸淀粉酯的酶催化合成。主要考察了酶与淀粉的质量比、反应温度、底物比、时间等参数对油酸淀粉酯取代度的影响。采用气相色谱法进行取代度的测定,并以取代度为考察指标,确定了最佳的工艺条件。在单因素试验的基础上进行正交试验,结果表明,最佳工艺条件为:酶的添加量为6%、温度70℃、底物质量比1∶7,在上述条件下反应12 h,取代度可达0.201。同时,使用紫外吸收光谱和FT-IR谱图对产物结构进行表征。

Oleic acid starch ester was synthesized by using immobilized lipase Novozym435 as the biocatalyst in the solvent -free system. Several factors, such as the ratio of lipase to starch, esterification temperature, esterification time and ratio of acyl donor and acceptor substrates has been investigated in the solvent - free system. A novel GC - based method was used to measure the degree of substitution（DS） of oleic acid starch ester. DS as the research object was adopt to optimize the reaction conditions. According to the results of the single - factor experiments, the perpendicular experiments were designed to optimize the parameters of the reaction. The results showed that the optimum reaction conditions were as below： concentration of lipase was 6% ,the ratio of starch to oleic acid 1：7 （W/W） ,the reaction temperature 70 ℃, the reaction time 12 h. A degree of substitution of 0. 201 was obtained. The structures of products were characterized by UV absorption spectra and FT- IR spectra.