硬脂酸淀粉酯的酶促合成及其乳化稳定性

Enzymatic synthesis and emulsifying stability properties of starch stearate

硬脂酸淀粉酯是通过淀粉酯化而得到的乳化剂,它是由淀粉及其衍生物与硬脂酸、硬脂酸甲酯、硬脂酸酰氯或硬脂酸酸酐反应得到的酯化产品。硬脂酸淀粉酯由于疏水性有机碳链的引入,淀粉的疏水性增加,使之具备了亲油和亲水的双亲性质,可广泛应用于日用化学、食品、纺织化工,生物降解材料、医药等工业。目前合成硬脂酸淀粉酯所用方法主要是水媒法、溶剂法、熔融法等。本实验采用脂肪酶LipozymeTL IM为催化剂,马铃薯淀粉与硬脂酸为反应底物、焦磷酸钠为辅助剂,合成硬脂酸淀粉酯。在脂肪酶添加量为淀粉质量10%的条件下,考察了底物比,辅助剂用量,反应时间,反应温度对酯化效果的影响,确定了酶法合成硬脂酸淀粉酯的最佳条件:淀粉6.0g,硬脂酸20.0g,焦磷酸钠1.5g,反应时间42h,反应温度65℃,制得取代度为0.036的淀粉酯产品。所得淀粉酯具有良好的乳化能力。

The preparation of starch stearate is carried out by converting the starch or its derivatives with stearic acid,stearic acid ester,stearic acid chloride or stearic acid anhydride.With its properties of lipophilic and hydrophilic,stearic acid can be widely used in the fields such as food,medical science,daily chemical industry,biodegradable materials.At present,the method for the preparation of stearic acid are as follows：organic solvent method,melting method and hydrophily method.In this paper,synthesis starch stearate with lipase Lipozyme TL IM as the catalyst,and potato starch and stearic acid as the reaction substrate,and sodium pyrophosphate as the adjuvant.The effect of substrate ratio,the dosage of sodium pyrophosphate,reaction time,reaction temperature on esterification was investigated on the conditions that the dosage of lipase is 10% of starch stearate mass fraction.The optimum conditions were：potato starch,6.0g,stearic acid,20.0g,sodium pyrophosphate,1.5g,reaction time,42h,reaction temperature,65℃.The degree of substitution of the product was 0.036 under the optimum conditions.And emulsifying properties of starch stearate was good.