碱法制备的4种淀粉-脂肪酸包合物的热力学性质研究

Thermal Properties of Four Kinds of Starch-fatty Acid Inclusion Complexes Prepared by Alkaline Method

摘要:

采用差示扫描量热仪、热重分析仪和X-射线衍射仪研究绿豆淀粉、木薯淀粉、甘薯淀粉和马铃薯淀粉对HCl/KOH法制备的淀粉-脂肪酸包合物糊化和热分解性质、玻璃化转变温度（Tg）、结晶结构等的影响。研究表明，淀粉与脂肪酸复合后晶型变为V型。在薯类淀粉-硬脂酸包合物中，马铃薯淀粉-硬脂酸包合物的糊化温度、Tg和热分解稳定性最高，木薯淀粉-硬脂酸包合物的糊化温度、Tg和热分解稳定性最低。在薯类淀粉-油酸包合物中，木薯淀粉-油酸包合物的糊化焓值（?H）最高，热分解稳定性最小；甘薯淀粉-油酸包合物的?H最低，热分解稳定性最大。比较马铃薯淀粉和绿豆淀粉，马铃薯淀粉-硬脂酸包合物的糊化温度、热分解稳定性高于绿豆淀粉-硬脂酸包合物；马铃薯淀粉-油酸包合物的?H和Tg高于绿豆淀粉-油酸包合物。

Abstract:

The effect of mung bean starch, cassava starch, sweet potato starch, and potato starch on the gelatinization properties, thermal decomposition properties, glass transition temperature (Tg), and crystal structure of starch-fatty acid inclusion complexes prepared by HCl/KOH method were studied by differential scanning calorimeter, thermogravimetric analyzer, and X-ray diffractometer. The results showed that the crystal form of the starches was transformed to V-type after complexation with fatty acids. The highest gelatinization temperature, Tg, and thermal decomposition stability were present in potato starch-stearic acid inclusion complexes, while those of cassava starch-stearic acid inclusion complexes were the lowest. Among the three kinds of root and tube starch-oleic acid inclusion complexes, the cassava starch-oleic acid inclusion complex had the highest gelatinization enthalpy (?H) and the lowest thermal decomposition stability, but the sweet potato starch-oleic acid inclusion complex had the lowest ?H and the highest thermal decomposition stability. The gelatinization temperature and thermal decomposition stability of potato starch-stearic acid inclusion complexes were higher than those of mung bean starch-stearic acid inclusion complexes, while the ?H and Tg of potato starch-oleic acid inclusion complexes were higher than those of mung bean starch-oleic acid inclusion complexes.