羟丙基糯玉米淀粉的制备及其性质的研究

Study on the preparation and properties of hydroxypropyl waxy maize starch

以糯玉米淀粉为原料,环氧丙烷为醚化剂,在碱性条件下对羟丙基淀粉的制备工艺及其性质进行了研究。考察了醚化剂、膨胀抑制剂、pH、反应温度、反应时间对羟丙基淀粉取代度和反应效率的影响。实验结果表明,随着pH的增大,羟丙基淀粉的取代度和反应效率都增大;提高反应温度,羟丙基淀粉的取代度和反应效率都增加;增加环氧丙烷的用量,羟丙基淀粉的取代度随之增加,但反应效率呈下降的趋势;延长反应时间,淀粉的取代度和反应效率都呈上升趋势;增加硫酸钠的用量,羟丙基淀粉的取代度和反应效率都先增大,当硫酸钠用量超过12g时,随着硫酸钠用量的增加取代度和反应效率都降低。并且确定出最佳的反应条件:淀粉用量为100g时,pH为11.5,膨胀抑制剂12g,环氧丙烷10mL,反应温度50℃,反应时间20h。随着羟丙基糯玉米淀粉取代度的增加,其冻融稳定性、透明度、耐酸性、黏度热稳定性都增加。

In this study, the waxy maize starch is used as the raw material, propylene oxide was the etherification reagent to study the preparation and properties of hydroxypropyl starch. The effects on substitution degree and reaction efficiency by various factors such as the etherification reagent, the expansion inhibitor, the pH value, the reaction temperature and time were investigated. The results showed that with the increase of pH value, the substitution degree and re- action efficiency of waxy maize starch were increased ; with the increasing of the reaction temperature, the substitution degree and reaction efficiency were increased; with the increasing the amount of propylene oxide, the substitution degree was increased, but the reaction efficiency was in the downward trend. If the reaction time was extended. The substitution degree and reaction efficiency were in the upward trend ; increasing the amount of sodium sulfate, the substitution degree and reaction efficiency were increased first and then reduced when more than12g sodium sulfate added. The optimum reaction conditions were as follows： waxy starch 100g, pH value 11.5, expansion inhibitor 12g, propylene oxide 10mL, reaction temperature 50℃reaction time 20h. With the increase of the substitution degree, the freeze thaw stability, luminosity, acid resistance and viscosity and thermal stability of hydroxypropyl waxy maize starch were all increased.