X-ray diffractograms of starches were recorded using a D/max-
2500vk/pc X-ray diffractometer (Rigaku Corporation, Tokyo,
Japan) operating at 40 kV and 30 mA. Starch samples were equilibrated
at constant humidity (75%) in a desiccator over a saturated
NaCl solution for one week before analysis. The samples were
scanned from 3 to 40 (2q) at a speed of 1 /min and a step size of
0.02. The degree of crystallinity was calculated as a ratio of the
sum of areas under the crystalline peaks to the total area under the
diffraction curve between 3 and 40 (2q) using the Origin software