木薯淀粉交联羧甲基化改性及工艺优化

Cross-linked carboxy methylation modification of cassava starch and reaction optimization

用搅拌球磨机活化木薯淀粉,将经活化60min的木薯淀粉用环氧氯丙烷进行适度交联,再将交联淀粉与一氯乙酸钠通过干法工艺制备交联羧甲基复合淀粉。以取代度为评价指标,探讨交联度、反应温度、反应时间、一氯乙酸钠用量、氢氧化钠用量和含水量等因素对淀粉羧甲基化反应的影响,通过正交试验优化制备条件。结果表明,使用中等交联度的交联淀粉在反应时间150min、反应温度55℃、淀粉与一氯乙酸钠的摩尔比0.55、淀粉与氢氧化钠的摩尔比0.50,体系含水量24%的条件下制得的复合淀粉取代度为0.841。

The cassava starch mechanically activated for 60 rain using a stirring-type ball mill was cross-linked moderate with epichloro- hydrin, and then the cross-linked carboxymethylated composite starch was prepared by dry method using cross linked starch and so dium chloroacetate. The effects of crosslinking degree, reaction time, reaction temperature, sodium chloroacetate amount, sodium hydroxide amount and system water content to the etherification re- action of cross-linking starch were investigated respectively by using degree o（ substitution（Ds） as evaluating parameter, and the prepara tion process of cross-linking carboxymethylated composite starch with orthogonal experiment was studied. The results indicated that degree of substitution of the cross linked carboxymethylated compos ire starch prepared by the middle cross-linking degree starch was 0. 841, when the reaction time was 150 min, the reaction tempera- ture was 55 ℃, the mole ration of starch to C1CH2COONa was 0.55, the mole ration of starch to NaOH was 0.50, the system wa- ter was 24%.