无溶剂体系酶促合成肉豆蔻酸淀粉酯及其性质研究

摘要

在无溶剂体系中,采用Novozyme 435作为催化剂,肉豆蔻酸和马铃薯淀粉作为原料,制备不同取代度的肉豆蔻酸淀粉酯.研究反应温度、脂肪酶添加量、底物比(淀粉∶肉豆蔻酸)及反应时间对淀粉酯取代度的影响,并对原淀粉及不同取代度的酯化淀粉的物化性质进行了研究.结果表明,反应温度60℃,脂肪酶添加量2％,底物比1∶4,反应时间25 h时,制得的肉豆蔻酸淀粉酯的取代度为0.056.肉豆蔻酸淀粉酯具有较好的疏水性及乳状液稳定性,凝胶强度较原淀粉有所下降.%In the solvent-free system,myristic acid and potato starch were used as raw materials,using Novozyme 435 as catalyst,to prepare starch myristate with different degrees of substitution.Effects of reaction temperature,the amount of lipase,starch/myristate acid weight ratio and reaction time on the degree of substitution of starch esters were studied.Then chemical and physical properties of native potato starch and esterified starch with different degrees of substitution were measured.The results showed the DS of the esterified starch was 0.056 when reaction temperature was 60 ℃,lipase dosage was 2％,substrate ratio was 1∶4,and reaction time was 25 h.Esterified starch had good hydrophobicity and emulsion stability,and the gel strength was declined compared with the native starch.