Basis for varietal difference in popping expansion of rice

Abstract

Twenty-five varieties of paddy differing widely in their popping expansion were analysed for their chemical and physical characteristics. Non-starchy polysaccharides (tested in 10 varieties), amylose and protein; grain length, thickness and weight; huskto- kernel gap; and thickness of pericarp and aleurone layer (in 10 varieties) were unrelated to popping expansion. Tightness of husk (lemma-palea) interlocking and grain hardness were strongly positively correlated with popping and 'white belly' (grains containing opaque, chalky regions) was negatively correlated. Multiple correlation analysis showed that these three Cactors could explain 80% of the variation in popping expansion among the variations; these factors along with the content and thickness of husk, equilibrium moisture of paddy, and cracked grains together explained over 95 % of the variation. Grain breadth was positively correlated to white belly and thus indirectly affected popping inversely.