摘要
研究经机械活化预处理后的玉米淀粉乙酰化反应的规律,分别考察了机械活化时间、反应时间、反应温度、催化剂用量及醋酸酐用量对取代度的影响。实验结果表明,机械活化能显著提高玉米淀粉乙酰化反应的取代度,反应时间缩短,反应温度降低,对催化剂和醋酸酐用量依赖性降低。机械活化作用能破坏玉米淀粉的结晶结构,反应试剂的扩散阻力下降,乙酰化试剂更容易渗透到颗粒内部,使乙酰化反应进行的几率增大,有效地提高了玉米淀粉的化学反应活性。
The reaction of acetylating on maize starch pretreated with mechanical activation was studied.The effects of mechanical activation time, reaction time, reaction temperature, acetic anhydride content and catalyst content on the degree of substitution （DS） of starch acetate were investigated respectively. The results showed that mechanical activation obviously increased the DS of acetylating on maize starch. It made reaction time short and reaction temperature decrease,the DS on the acetic anhydride content and catalyst content was reduced.Since the crystal structure of maize starch was destroyed by mechanical activation, the reagent acetylated was easier to diffuse into starch molecule interior,the mechanical activation considerably enhanced the chemical reaction activity of maize starch,and then enhanced the reaction activity of acetylating on starch.
出处
《食品工业科技》
CAS
CSCD
北大核心
2009年第3期217-219,222,共4页
Science and Technology of Food Industry
基金
广西教育厅科研项目(200708LX139)。
关键词
玉米淀粉
机械活化
乙酰化
取代度
反应活性
maize starch
mechanical activation
acetylating
degree of substitution
reactivity
