Varietal Difference in Popping and Endosperm Characters Associated with Popping Quality of Rice

This study was carried out to identify varietal differences in popping characteristics of brown and polished rice and to elucidate the morphological and physicochemical properties related to popping quality. Nineteen rice varieties including japonica, indica, and javanica were tested for popping quality and physicochemical properties of rice grains. The rice varieties showed large varietal differences in popping characteristics and physicochemical properties of endosperm. The bulk density of popped brown and polished rices ranged 58~183 g/l and 69~184 g/l, respectively. The ratio of popped brown rice ranged from 50.6% to 98.0% and the ratio of intact popped brown rice was scattered markedly from 10.5% to 94.2%. Also, the varietal difference in volume expansion rate of popped milled rice was widely scattered from 6.1 to 14.0 times larger than that of raw milled rice. The better popping-quality rice varieties revealed the lower bulk density of popped rice, the higher ratio of popped rice grains, and the larger volume expansion rate of popped milled rice. Moreover, better popping quality was closely associated with lower amylose content and softer gel consistency of rice flour. The glutinous or chalky non-glutinous rices showed very low ratio in intactness of popped brown rice because of much more bursted popping.