Rice Aroma and Flavor: A Literature Review

Descriptive sensory analysis has identified over a dozen different aromas and flavors in rice. Instrumental analyses have found over 200 volatile compounds present in rice. However, after over 30 years of research, little is known about the relationships between the numerous volatile compounds and aroma/flavor. A number of oxidation products have been tagged as likely causing stale flavor. However, the amounts of oxidation products, singly or collectively, that need to be present for rice to have stale or rancid flavor have not been established. Only one compound, 2-acetyl-1-pyrroline (2-AP; popcorn aroma) has been confirmed to contribute a characteristic aroma. Furthermore, 2-AP is the only volatile compound in which the relationship between its concentration in rice and sensory intensity has been established. This article discusses the challenges of measuring aroma and flavor instrumentally and by human sensory panels and reviews research examining the effects of genetic, preharvest, and postharvest factors on volatile compound profiles and the aroma and flavor of cooked rice.