影响甘薯淀粉磷酸单酯取代度的因素研究

Factors Influencing Degree of Substitution of Phosphate Monoester of Sweet Potato Starch

以磷酸二氢钠和磷酸氢二钠为酯化剂对甘薯淀粉进行酯化反应 ,研究不同因素对淀粉磷酸单酯取代度的影响。结果表明 :甘薯淀粉磷酸单酯的取代度随酯化剂用量、反应温度、反应时间以及催化剂用量的增加而增大 ,随p H值升高先增后减 ,酯化剂配比和真空度对其影响不明显。固定酯化剂配比 ,制备甘薯淀粉磷酸单酯的最佳工艺条件为 :反应温度 130～ 14 0℃ ,反应时间 2～ 3h,p H值 5 .5～ 6 .0、酯化剂的配比 3∶ 1,催化剂用量为淀粉质量的4 %～ 6 %。

Factors influencing the degree of substitution (DS) of phosphate monoester of sweet potato starch with esterification of sodium phosphate monobasic (Na 2HPO 4) and sodium phosphate dibasic (NaH 2PO 4) were systematically investigated. The results indicated that the degree of substitution of phosphate monoester increased with the level of esterifying agent, reaction temperature, reaction time, and the amount of catalyzer. However, when pH value increased, DS first increased, then decreased. The combination of Na 2HPO 4 and NaH 2PO 4 and vacuum had no marked influence on DS. Based on above results, the optimum parameters for the preparation of phosphate monoester of sweet potato starch was selected as follows: the reaction temperature is 130~140℃, reaction time is 2~3 h, pH value is 5 5~6 0, the ratio of Na 2HPO 4 to NaH 2PO 4 is 3, and the concentration of catalyzer is 4%~6% of starch weight.