• 作者： Yong-Ching Yang, Shaik Ramjan Vali, and Yi-Hsu Ju
• 中文摘要： --
• 英文摘要： Synthesis of high-purity (> 99%) monostearin was carried out using a two-step process. The first step involved lipase-assisted enzymatic esterification of fatty acid with glycerol catalyzed by immobilized lipase Candida antarctica (Novozym 435) in acetone. The reaction was carried out at a fatty acid (FA) to glycerol molar ratio of 1:4 with 5% lipase based on the fatty acid (FA) weight. Equilibrium was attained within 8 h with a monoglyceride (MG) content and a degree of esterification of 82.4 wt% and 85.5%, respectively. The addition of solvent shifted the equilibrium toward product formation and resulted in further increases of the MG content and the degree of esterification to 89.7 wt% and 92.7%, respectively, after 16 h (total: 24 h). The major impurities in the reaction product were free fatty acids (up to 7 wt%) and di- and triglycerides (< 3.5%). The second step involved the removal of fatty acids by a mild alkali treatment, and it produced MG with purity greater than 99 wt% and an overall yield of 66.8%. Comparison of various solvents shows that the extent of esterification and product selectivity are strongly dependent on the solubility-solvation of the substrate and product in the reaction medium. Thus, monoglycerides was carried out using monostearin synthesis as model system in this investigation.
• 中文關鍵字： --
• 英文關鍵字： --