机械活化木薯淀粉羧甲基化产物糊性质的研究（Ⅱ）

摘要

Cassava starch was subjected to mechanical activation for 60 min on a stirring-type ball mill.Carboxymethyl starch（CMS） was prepared by using activated cassava starch as the raw material,NaOH as the catalyst and ClCH2COOH as the etherification agent.The effects of temperature,CMS concentration,pH,electrolyte,storage time and shear stress on the viscosity of CMS paste were investigated.The results showed that the viscosity of CMS paste was relatively stable between 25 ℃ and 40 ℃,and revealed a gradual decrease at temperatures over 40 ℃.Meanwhile,the viscosity of CMS paste was increased with increasing CMS concentration.CMS paste revealed weak resistance to acid,alkali and salts,the highest viscosity in neutral medium and high sensitivity to NaCl,but was not steady at normal or low temperatures and close to Newtonian liquid.%采用搅拌球磨机对木薯淀粉进行机械活化,以活化60min的木薯淀粉为原料,NaOH为催化剂,一氯乙酸为醚化剂,干法制备羧甲基淀粉,探讨温度、质量浓度、pH值、电解质、放置时间、剪切应力等因素对产物糊黏度的影响。结果表明：机械活化木薯淀粉羧甲基化产物糊的黏度在25～40℃的范围内保持相对稳定,温度大于40℃后,糊的黏度随温度升高而降低;糊黏度随淀粉质量浓度的增大而增大;在中性介质中糊黏度最高,但抗酸碱能力不强;糊黏度对NaCl比较敏感,抗盐能力较差;糊在常温状态易于凝沉而不太稳定;糊液接近牛顿流体。