机械活化强化木薯淀粉液化的动力学研究  

Study on dynamics in enhancing liquefaction of cassava starch by mechanical activation

作　　者：胡华宇[1] 黄祖强[1] 童张法[1] 袁建微[1] 

机构地区：[1]广西大学化学化工学院,广西南宁530004

出　　处：《食品与机械》2008年第1期25-28,31,共5页Food and Machinery

基　　金：国家自然科学基金资助项目(项目编号:20666001);广西自然科学基金资助项目(项目编号:0640006);广西大学科研基金资助项目(项目编号:X071073)

摘　　要：目的:对机械活化木薯淀粉进行液化动力学研究,探讨机械活化对淀粉降解的影响规律;方法:采用搅拌球磨机对木薯淀粉进行机械活化,以不同活化时间的木薯淀粉为原料,以α-淀粉酶为液化试剂,分别考察底物浓度、酶用量、反应温度、反应体系pH值、机械活化时间等动力学因素对液化反应速率的影响;结果:α-淀粉酶对机械活化淀粉的液化遵循Michaelis-Menten方程,原淀粉、活化30,60min淀粉的米氏常数Km分别为1.9282,2.5505,5.7561mg/mL,最大反应初速度νmax分别为0.0966,0.3356,0.7475mg/mL.min;结论:机械活化对木薯淀粉液化过程有显著的强化作用,主要原因是机械活化使木薯淀粉紧密的颗粒表面和结晶结构受到破坏,降低了结晶度,液化试剂更容易渗透到颗粒内部使淀粉液化。Objective ： Study on dynamics in liquefaction of cassava starch by mechanical activation ; Methods： Cassava starch was mechanically activated by a stirring-type ball mill. Using α-amylase as liquefaction reagent from cassava starch with different activation times, effects of substrate concentration, α-amylase amount, reaction temperature, pH value of the reaction system and mechanical activation time on reaction rate were investigated respectively; Results： Experimental results indicated that the liquefaction rule of mechanical activated starch followed Michaelis-Menten equation, the Michaelis constant （Km） were 1. 928 2 mg/mL（ non-activated）, 2. 550 5 mg/mL （activation time 30 min）, 5. 756 1 mg/mL （activation time 60 min）, and maximum velocity（ Vmax ） were 0. 096 6,0. 335 6,0. 747 5 mg/mL · min;Conclusion： It showed that mechanical activation considerably enhanced the liquefation of cassava starch. The reasons are that the crystal structure and compact granule surface of cassava starch were destroyed by mechanical activation, the crystallinity decreased and reagents were easier to diffuse into starch intra-molecules.

关 键 词：机械活化 液化 木薯淀粉 动力学 

分 类 号：TS231[轻工技术与工程—粮食、油脂及植物蛋白工程]