菊粉酸降解动力学研究

Kinetic Studies on Acid Catalyzed Hydrolysis of Inulin

通过考察温度、溶液pH值及水分含量对菊粉酸降解的影响,探索菊粉酸水解规律。结果表明:菊粉水溶液在pH 5.0～7.0、温度低于100℃时具有良好的稳定性;但当pH值低于4.0时,菊粉出现明显的水解反应。菊粉溶液在不同温度和pH值下的酸降解动力学表明,其水解反应遵循一级反应动力学方程。利用菊粉凝胶特性考察水分含量与菊粉酸降解的关系,发现相同pH值(pH=3)条件下,水分含量越高,菊粉降解速率越快,凝胶中菊粉降解速率低于菊粉水溶液降解速率。

The effects of temperature,pH and water content on inulin hydrolysis were studied to understand the acid catalyzed hydrolysis process of inulin for industrial production of high-fructose syrup.The results showed that inulin solution had a good thermal stability at a pH value in the range of 5.0-7.0 and a temperature below 100 ℃,while inulin degradation started to occur when the pH was lower than 4.0.The acid catalyzed hydrolysis dynamics of inulin at different levels of temperature and pH showed that the reaction followed the first-order kinetics well.The relation between inulin gel degradation induced by acid and water content was also investigated.At the same pH,the higher water content,the faster inulin hydrolysis,and the degradation rate of inulin was lower in gel than in aqueous solution.