INFLUENCE OF STORAGE ON SUPERCOOLING OF RICE STARCH AND FLOUR GELS

Supercooling of amylose-amylopectin mixtures and starch or flour gels from fresh and stored rice has been studied. The results showed that the extent of supercooling of the amylose-amylopectin gels was indirectly related to the amylose content. Amylose solutions or gels did not supercool and, in the mixtures with amylopectin, inhibited supercooling. The supercooling of starch gels was influenced by oryzenin (rice storage protein). The supercooling of starch or flour gels from different varieties of postharvest and stored rice was related to the molecular weight of oryzenin and starch, oryzenin-starch interactions, and water binding, which reflected the structural changes of oryzenin and starch during rice storage.