籽粒苋淀粉的交联变性反应及其产物理化性质研究OA北大核心CSTPCD

To investigate the cross-linking denaturation reaction characteristics of very small granular starch and the physicochemical properties of the products with different degrees of substitution,in this study,the effects of temperature(45,50,55 ℃),pH(9.0,10.0,11.0)and expansion inhibitor Na2SO4 concentration(5％,10％,15％)on the process and efficiency of the cross-linking reaction were investigated and physicochemical properties of the cross-linking products with different degrees of substitution(DS)were compared using amaranth starch as raw material,sodium trimetaphosphate as denaturant and waxy corn starch(WCS)as control.The results showed that the cross-linking reaction of AS was less influenced by temperature compared to WCS,and it was difficult to increase the efficiency of the cross-linking reaction by simply increasing the temperature.On the contrary,both pH and Na2SO4 concentration promoted the cross-linking denaturation reaction of AS and WCS,and higher pH levels(10.0～11.0)and Na2SO4 concentrations(5％～15％)led to faster rates of cross-linking reaction.The viscosity of low-substitution cross-linked AS(DS 0.1 × 10-3～0.8× 10-3)after pasting was greater than 50 cP with a stable thickening effect;high-substitution cross-linked AS(DS≥ 0.8×10-3)exhibited a viscosity below 50 cP after pasting,with a weak thickening ability and a fat-like appearance and texture.This study showed that pH and the concentration of expansion inhibitor Na2SO4 were effective means of regulating the reaction rate of amaranth starch,and that cross-linked amaranth starch had a weak thickening ability but good viscosity stability and shear resistance,which was potentially valuable in its application as a fat substitute.