Effects of the Removal of Lipids and Surface Proteins on the Physicochemical and Structural Properties of Green Wheat Starches

Abstract

Abstract Green wheat starch and its isolated A‐ and B‐type starch granules are physically modified by deproteinization and defatting treatments. After these treatments, the morphology of the starch granules is changed as the aggregation disappears and the partial starch granule structure is disrupted. The birefringence and X‐ray diffraction patterns of all the starch samples are not changed by these treatments, while the relative crystallinity of the starch samples increases on deproteinization and decreases on defatting treatment. 13 C nuclear magnetic resonance reveals that deproteinization and defatting cause an increase and decrease in the double helix content of the starch samples. These changes lead to different effects on the physicochemical properties of the various starch samples. Deproteinization increases the gelatinization temperature ( T o , T p , T c ) and the derivative peak temperature ( T Peak ) of green wheat starch and its isolated A and B‐type starch granules, which is related to the increase in the relative crystallinity. Overall, the deproteinization treatment has a more obvious effect on the physiochemical and structural properties of starch granules than the defatting treatment.