三氯氧磷交联程度对木薯淀粉体外消化性能和抗消化淀粉形成的影响

利用体外消化模型对不同交联度的三氯氧磷交联木薯淀粉的消化速度和抗消化性能进行了研究。研究结果表明,三氯氧磷交联木薯淀粉被唾液α-淀粉酶消化的速度随交联度的增大而降低。高交联降低淀粉颗粒和淀粉糊的消化速度,低交联增大淀粉颗粒的消化速度但对淀粉糊的消化速度影响程度较小。同时用Megazyme全淀粉分析盒分析了三氯氧磷交联反应对木薯淀粉抗消化性能的影响。三氯氧磷交联木薯淀粉被酶水解的程度随交联程度的增大而降低,且所含的抗消化淀粉的总量也随着交联程度的增大而减少。高交联特别是使淀粉达到非晶化时淀粉的抗消化性能越强。但是在交联度小于1.71×10-2的范围内,凝沉的交联淀粉消化程度随着交联程度的提高而增大,当交联度继续增大时消化程度则降低。通过控制淀粉的交联程度可以调节淀粉与酶反应的敏感程度和反应活性,从而影响淀粉的营养特性。

Effect of Cross-linking of POCl3 on in vitro Digestibility and Formation of Enzyme Resistant Starch of Tapioca Starch

The rate of starch digestibility and the enzymatic resistivity was evaluated in some cross-linked tapioca starch in terms of in vitro model and the effect of cross-linking on the reactivity of tapioca starch by enzyme were discussed. The results showed that the starch digestion rate by salivary α -amylase is decreased as the degree of cross-linking increased. High crosslinking degree of starch granules decreased the digestion rate. However, low cross-linked reaction increased the rate of starch granule but had little effect on its pastes. Moreover, the influence of cross-linked with POCl3 on the enzymatic resistivity was revealed by using the Megazyme total starch assay kit. The decrease in enzyme hydrolysis after cross-linking was higher as cross-linking degree increased and the amount of total resistant starch increased. These decreases were higher in high cross-linked tapioca starch where granular structure became non-crystallized. But for the retrograded cross-linked tapioca starch, the percentage of enzyme hydrolysis increased with the increase of cross-linking degree until 1.71 × 10-2 and then decreased. It is concluded that the sensitivity of starch granules to enzyme and their reactivity can be regulated by controlling the degree of cross-linking(DC),which is likely to affect the nutritional characteristics of tapioca starch.