环境友好型食品添加剂蔗糖酯的合成研究进展

On the synthesis of environment-friendly food additive sucrose esters

综述了蔗糖酯的合成方法及工艺的研究进展。蔗糖酯的合成方法主要有4种:酰氯酯化法、直接脱水法、酯交换法及微生物法。酰氯酯化法是蔗糖和脂肪酸酰氯反应生成蔗糖酯。直接脱水法是蔗糖与脂肪酸反应生成蔗糖酯。酯交换法包括溶剂法和无溶剂法。溶剂法采用N,N-二甲基甲酰胺(DMF)、二甲亚砜(DMSO)、丙二醇或水为溶剂,但DMF和DMSO这两种溶剂均有毒,限制了其在食品等行业的应用,采用丙二醇或水作溶剂,需加入乳化剂,产品纯化困难;无溶剂法则是通过向反应体系中加入乳化剂使熔融相成均一相,但反应温度比较高,产率低。微生物法是一种新的生物合成方法,采用酶代替传统的催化剂合成蔗糖酯,该法反应条件温和,选择性强,产品易纯化。最后对其他辅助方法做了简要介绍。

This paper reviews the advances and up-to-date methods of synthesis and procedure of sucrose esters in addition to introduction to its reaction mechanism. Divided by its reaction ways, here are four ways to synthesize sucrose ester, that is, chloride esterification method, direct esterifieation method, transesterification method and enzyme catalyst method. Chloride esterification method： in the presence of a catalyst, sucrose ester is synthesized by the reaction of sucrose to fatty acid chloride. The need to use toxic solvents, as is known in this area, makes it difficult for the synthesis to come to the national standards for food products, cosmetics and pharmaceutical goods made in chloride esterification method. The direct esterifieation method as is mentioned above, in actual application, ealls for an acid catalyst （e. g. tosylate） . When sucrose ester is synthesized with fatty acid ester, it is necessary to use polar aprotic organic solvents （e. g. DMF） in the process, which seems simple and easy to operate for its synthesis but DMF proves toxic, for it is not easy to purify sucrose es- ters. The reason is that ester is decomposed easily in the acidic conditions, which result in low yield. Transesterification includes solvent method and solvent-free method. The former uses DMF, DMSO, propylene glycol or water as solvent, but both DMF and DMSO are somewhat toxic, which restricts the applications of sucrose esters in food industry. If propylene glycol or water is used as solvent, the emulsifying agent to be added to the process also makes it difficult to purify the sucrose esters. If non-solvent method is used, emulsifying agents or surfactants to be added to the reaction system tends to make the melting reactants homogenous. If the temperature of the reaction is used, the yield would also be made low, besides, the quality of the product can not be guaranteed. Seeing the shortcomings of all the above methods, a new biological synthesis method has been brought up forward, which is known as enzyme catalyst method. The enzyme catalyst, which is used for synthesis instead of the traditional catalysts, enjoys high selectivity and easy separation in the production process under moderated conditions. In spite of this, the paper has also made brief introductions to other auxiliary methods.