研磨强化无溶剂法合成蔗糖脂肪酸酯

Grind-strengthened solvent-free synthesis of sucrose fatty acid esters

摘要:

以蔗糖和脂肪酸甲酯为反应原料，无溶剂条件下采用研磨强化的方法合成了蔗糖脂肪酸酯，考察了研磨时间、乳化剂用量、反应时间、反应压力以及催化剂用量对蔗糖酯收率及蔗糖和甲酯转化率的影响，产品经水洗、醇提精制后，用FTIR和HPLC-ELSD对其进行了表征和分析。结果表明：研磨处理能将反应分散物粒径（D50）降至约5 μm，有效地增强了蔗糖与脂肪酸甲酯的无溶剂酯交换反应。得到的最优反应条件为：研磨时间为60 min，硬脂酸钾乳化剂质量分数为10%，K2CO3质量分数为2.0%，反应时间6 h，反应压力0.5 kPa，在该条件下脂肪酸甲酯转化率为91.2%，蔗糖酯收率为61.6%。精制后产品中蔗糖酯含量为81.9%，且其游离糖含量为0.6%，酸值为3.0 mg KOH/g，水分为0.2%和灰分为0.5%，均达到FAO/WHO标准。

Abstract:

A grind-strengthened strategy was developed for the solvent-free synthesis of sucrose fatty acid esters (SE). The effect of grinding time, emulsifier, reaction time, reaction pressure and catalyst dosage on yields and production distributions of SE were investigated by using sucrose and fatty acid methyl ester as reactants. The generated SE was purified by using water washing and alcohol extraction. And they were characterized by the analysis of Fourier Transform Infrared Spectroscopy (FTIR) and High Performance Liquid Chromatography-Evaporative Light Scattering Detector (HPLC-ELSD). The results showed that the grinding pretreatment could reduce the particle size of reaction dispersion (D50) to 5 μm and effectively enhanced the solvent-free transesterification reaction of sucrose esters. Under the optimized conditions a fatty acid methyl ester conversion of 91.2% and a SE yield of 61.6% were achieved, in which the grinding time was 60 min, the dosage of potassium stearate was 10%, the dosage of potassium carbonate was 2.0%, the reaction was conducted under the pressure of 0.5 kPa for 6 h. The amount of SE reached up to 81.9% in the purified product, and its free sugar was 0.6%, acid value was 3.0 mg KOH/g, water content was 0.2%, ash content was 0.5%, and all these indicators completely accorded with the Food and Agriculture Organization / World Health Organization (FAO/WHO) standard.