棕榈酸木薯淀粉酯的制备及性能研究

Preparation and properties of palmitate cassava starch

以木薯淀粉为原料,棕榈酸为酯化剂,硅酸钠和醋酸为复合催化剂,采用干法工艺制备棕榈酸木薯淀粉酯。研究了棕榈酸用量、催化剂用量、反应时间、反应温度对淀粉酯取代度和表面张力的影响,研究了淀粉酯取代度与表面活性及乳化性能之间的关系。取代度的测试结果及红外光谱均表明淀粉已被成功酯化。当木薯淀粉用量为100 g,棕榈酸用量为15 g,复合催化剂(硅酸钠与醋酸质量比为5∶1)用量为7.5 g,反应温度为160℃,反应时间为4 h时,制得的棕榈酸木薯淀粉酯取代度(DS)为0.0123,棕榈酸含量为2.39%(w/w),临界胶束浓度为30 g/L,对应的表面张力为25.87 mN/m,具有较好的表面活性和乳化性能。

Using cassava starch as raw material,palmitic acid as esterification agent,sodium silicate and acetic acid as composite catalysts,palmitate cassava starch was prepared by dry process.The effects of palmitate,catalyst,reaction time and reaction temperature on the degree of substitution and surface tension of starch ester were studied.The relationship between the degree of substitution of palmitate cassava starch and its surface activity and emulsifying property was studied.The results of the degree of substitution and infrared spectrum show that the starch has been esterified by palmitate acid.The optimum reaction conditions are as follows:the amount of cassava starch is 100 g,the amount of palmitic acid is 15 g,the amount of composite catalyst(the mass ratio of sodium silicate to acetic acid is 5∶1)is 7.5 g,the reaction temperature is 160℃,and the reaction time is 4 h.The DS of the product is 0.0123,its palmitate content is 2.39%(w/w),the critical micelle concentration is 30 g/L,and its surface tension is 25.87 mN/m.The test results indicate that the palmitate cassava starch has good surface activity and emulsifying property.