Effect of the crystal size on the X-ray diffraction patterns of isolated orthorhombic starches: A-type

The x-ray diffraction (XRD) patterns reported for starch in the literature describes it as a semicrystalline polymer that indicates that amorphous and crystalline regions form it, and this is commonly accepted. However, these patterns have not been well interpreted according to the XRD theory, and the crystal size effect has been neglected. A simulation of the effect of the crystal size on the shape and width on XRD patterns for A-type (orthorhombic structure, ICDD card No. 00-043-1858) using PDF-4 software shows that the patterns of starches are governed by the elastic and inelastic scattering producing wide peaks. For isolated starches XRD patterns, the separation of inelastic and elastic scattering is not possible, then the calculation of the crystalline percent or crystalline quality does not make any physics sense.