一步和二步改性法对交联酯化甘薯淀粉性质的影响

以三偏磷酸钠(STMP)为交联剂,醋酸酐为酯化剂,对甘薯淀粉进行复合变性,通过一步和二步改性法制备交联酯化改性甘薯淀粉。比较了一步和二步改性法对交联酯化甘薯淀粉性质的影响。一步法指甘薯淀粉交联后调整酯化的条件,省去水洗、中和与干燥操作工序连续进行酯化;二步法为将制备的交联淀粉粉碎干燥后作为酯化变性反应的原淀粉。以峰值粘度和稳定性为指标测定。结果表明:一步法改性的交联酯化甘薯淀粉具有更好的峰值粘度和稳定性;二步法改性的交联酯化甘薯淀粉具有更好的抗凝沉性,溶解度和膨胀度略高于一步法,抗冻融性更好,但与一步法差别不显著。

Effect of one-step and two-step modified method on the property of cross-linked esterification sweet potato starch

Sodium trimetaphosphate was used as cross-linking agent and acetic anhydride as esterifying agent to prepare cross-linked esterification sweet potato starch through one-step and two-step modified method. The effect of one-step and two-step modified method on the property of cross-linked esterification sweet potato starch was compared in this study. As to one-step modified method,sweet potato starch slurry was adjusted to appropriate condition after being cross-linked and then esterified directly where wash,neutralization,dry was eliminated. As to two-step modified method,cross-linked sweet potato starch was well dried and smashed,which was used as the raw starch for the next step of esterification. Peak viscosity and stability were chosen as index and the result indicated that the cross-linked esterification sweet potato starch prepared by one-step modified method possess better peak viscosity and stability. The cross-linked esterification sweet potato starch prepared by two-step modified method possess better anti-precipitability and freezing-thaw resistance,slightly higher solubility,swelling power,but the difference between two methods was not obvious.