Influence of waxy proteins on wheat resistant starch formation, molecular structure and physicochemical properties

This study investigated the influence of wheat waxy proteins on type III resistant starch (RS₃) formation, molecular structure and physicochemical properties. Waxy deletions led to a significant increase in B- and C-type starch granules, particle size of RS₃, and slowly digesting starch content, and a decrease in content of amylose and RS₃. X-ray powder diffraction and Fourier-transform infrared spectroscopy analyses revealed high relative crystallinity and long-range (1047/1022 cm^-1, IR₁) and low short-range (1022/995, IR₂) crystalline structures of RS₃ in waxy wheat, which suggests that waxy deletions could produce a more ordered crystalline structure and fewer amorphous regions in RS₃ crystals. Further laser confocal microscopy Raman spectroscopy analysis found that waxy deletions significantly increased the full width at half maximum and intensity of the bands at 480 cm^-1, as well as leading to more ordered RS₃ crystals. These changes in molecular structure resulted in improved physicochemical properties of RS₃.