Abstract
Changes in old rice smell of milled rice were examined with focus on the percentage composition of carbonyl and sulfur compounds. Such study has not yet been published. The rice samples (Oryza sativa L. var. japonica co. Nihonbare) were produced in Shiga Prefecture, Japan, and harvested from 1996 to 2001. The analysis focused on six carbonyl compounds, 1-propanal (1), 1-butanal (2), ethyl methyl ketone (3), 1-pentanal (4), 1-hexanal (5) and 1-heptanal (6), all of which are recognized as a contributing factor to old rice smell, and eight sulfur compounds. Aroma distinction analysis by the Aromalizer revealed a clear relationship between the age of the rice and old rice smell. We found a clear relationship between changes in the properties of cooked rice and the harvest year from the evaluation of cooked rice samples by aroma analysts.
