Physicochemical properties of starches from diverse rice cultivars varying in apparent amylose content and gelatinisation temperature combinations.

The physicochemical properties of starches isolated from 14 rice cultivars produced in China were investigated. These rice starches showed a non-random combination of AAC and GT. Rice starches showed a typical A-type diffraction pattern with the degree of crystallinity ranging from 32.3% (a high AAC rice) to 45.5% (a waxy rice). AAC was significantly correlated with the pasting, thermal and textural properties. The positive correlations were found with PV, HPV, CPV, SB and HD (p<0.05), while the negative corrections were found with SP, ADH, COH, T(o), T(p), T(c) and ΔH (p<0.05). However, AAC had no correlations with BD, PTime and percentage of retrogradation (R%). The degree of crystallinity and GT had a positive correlation with the retrogradation properties. It could be concluded that although AAC was the major factor affecting the physicochemical properties of rice starch, the retrogradation property of rice starch was mainly determined by the degree of crystallinity and GT.