磷酸酯化对甘薯淀粉凝沉性质的影响

Influence of Phosphorylation on Retrogradation of Phosphate Monoesters of Sweet Potato Starch

对甘薯淀粉的磷酸酯化制备条件及产物的凝沉性质进行了系统研究 ,结果表明 ,甘薯淀粉磷酸单酯的最适制备工艺为 :NaH2 PO4 :Na2 HPO4 =3∶1;反应温度 130℃～ 14 0℃ :反应时间 2～ 3h ,pH5 .5～ 6 .0 ,催化剂用量为淀粉干基重的 4 %～ 6 %。甘薯淀粉经过磷酸酯化反应后可能在脱水葡萄糖单元上引入了磷酸基团 ,从而导致了淀粉凝沉性质的变化 ,使得淀粉糊的凝沉趋势降低 ,透明度增高 ,冻融稳定性提高。

The preparation conditions and the retrogradation of phosphate monoesters of sweet potato starch were investigated.The suitable parameters for the preparation of phosphate monoester of sweet potato starch were selected as follows:molar ratio of Na 2HPO 4 and NaH 2PO 4 3∶1,reaction temperature 130℃～140℃,reaction time 2～3h,pH5.6～6.0,and the dosage of catalyzer4～6% of dry starch weight.After esterization,phosphate groups were linked with the anhydrous glucose units,and resulted in weakening of retrogradation,increase of paste clarity and improvement of freeze-thaw stability.