科研之友
微信
新浪微博
Facebook
分享链接
摘要
Cassava starch, as the raw material, was pretreated in alcohol-water phase, by which esterification reaction between the treated starch and octenyl succinic anhydride (OSA) was facilitated to yield OSASs with different degrees of substitution (DS). The influences of the starch concentration, reaction temperature, pH, dosage of octenyl succinic anhydride and reaction time on DS and reaction efficiency (RE) were studied. The preparation process of OSAS was optimized through orthogonal experiments, and the obtained optimal production conditions were: reaction time 4 h, reaction temperature 35℃, OSA dose 30%, pH 8.5, and starch concentration 35%. Under such conditions, the obtained OSAS had a DS of 0.0889 and RE of 38.47%. However, the degree of substitution and the reaction efficiency of esterified starch prepared with original cassava starch under the same condition were 0.0323 and 13.98% respectively, indicating the pretreatment could significantly improve RE. FT-IR analysis showed that the octenyl succinic acid groups were successfully introduced into the starch molecules. XRD analysis showed that the pretreatment made the original cassava starch transform partly from A-type crystal structure to V-type crystal structure, with its crystallinity decreasing from 21.48% to 8.61%. Esterification occurred firstly on the surface and in the amorphous region of starch, and then attacked the crystalline region and the inner structure, causing the decrease of crystallinity. The viscosity, retrogradation and the transparency of starch ester were significantly improved after esterification.
- 单位
