Abstract:Traditional burnt rice is widely desirable, however, the rice cooker program is not yet mature. Seven characteristic volatile flavor components of burnt rice, i.e., hexanal, methylpyrazine and etc., were identified by gas-mass spectrometry combined with odor activity value. Among them, pyrazines and thiazoles contributed to the burnt flavor, and aldehydes and phenols contributed to the fragrance flavor. The content of scorched flavor substances and associated harmful substances (5-hydroxymethyl-2-furaldehyde and acrylamide) gradually increased with the increase of temperature and time of stewing rice. The pyrazines in rice tended to be stable after heating at 175 ℃ for 20min, while the content of 5-hydroxymethyl-2-furaldehyde and acrylamide in rice were only 1.71 mg/kg and 0.08 mg/kg, respectively. The formation and accumulation of α-dicarbonyl compounds such as methylglyoxal promoted the production of characteristic flavor components of burnt aroma, and Amadori compounds were more likely to be transformed into harmful products at extremely high temperature(above 200 ℃). This study can provide a scientific basis for the directional regulation of the flavor of burnt rice and the reasonable design of cooking procedure of electric rice cooker.
