酯化交联淀粉反应及其性质的研究——淀粉颗粒糊化温度的变化

Studies on the Reaction and Properties of Esterified and Cross-Linked Starches ——The Gelatinization Temperature of Starch Granules

研究变性淀粉颗粒的糊化温度随反应 pH值、时间和三氯氧磷用量的变化规律 ,以及其DSC的糊化特性 .结果发现酯化交联淀粉的糊化完成温度比原淀粉高 ,随反应 pH值、时间和三氯氧磷用量的增加而升高 .当反应 pH值为 8.0和 9.0时 ,变性淀粉的糊化开始温度比原淀粉低 ,随反间时间、三氯氧磷用量的增加而降低 ;当反应 pH值为 10 .0和11.0时 ,变性淀粉的糊化开始温度的变化则随反应时间、三氯氧磷用量的增加而升高 ,其值从比原淀粉低上升至比原淀粉高 .这些变化规律同酯化交联淀粉的反应历程密切相关 .

The changes in the gelatinization temperature of esterified and cross_linked starches and the DSC gelatinization properties were studied with the reacting pH, time and the amount of phosphorus oxychloride. The upper limit of the gelatinization temperature range of modified starches was higher than that of the native tapioca starch, and it rose with the increasement of the reacting pH, time and the amount of the modified reagent. At the reacting pH of 8.0 and 9.0,the lower limit of the gelatinization temperature range of the modified starch was smaller than that of the native starch, and decreased with the increasement of the pH, time and the modified reagent. At the reacting pH of 10.0 and 11.0, the lower limit was smaller at the beginning of the reaction, and rose with the increasement of the above_mentioned reacting factors, finally reached value higher than that of the native starch. These properties were closely related to the mechanism of the esterification and the cross_link for starch.