Changes in crystal structure of chickpea starch samples during processing treatments: an X-ray diffraction and starch moisture analysis study

To detect more credibly the changes in the crystal structure of chickpea starch during processing treatments, two methods, a deconvolution method based on X-ray diffraction (XRD) pattern of starch and a moisture analysis method based on starch moisture content, were applied to determine the relative crystallinity (RC) of A- and B-type polymorphs (RCA and RCB) in the same chickpea starch sample. It was found that the values of RCA for chickpea starch samples determined by these two methods were close and showed similar trend. The results suggested that these two methods could be used to estimate RCA in the same chickpea starch sample and provide mutual corroboration. Based on the deconvolution method, it was observed that the crystalline region of chickpea starch was less susceptible to α-amylase hydrolysis than its amorphous region, and B-type polymorph in chickpea starch was more resistant to α-amylase hydrolysis than A-type polymorph.