Abstract:The heat treatment of electric cooker can enhance the flavor of rice by physical means, however, there is still a lack of corresponding mode in improving the flavor of aged rice. The crucial flavor compounds contributing to the stale odor of rice were identified as hexanal, octanal, nonanal and decanal analyzed by gas chromatography-mass spectrometry combined with flavor threshold analysis. Using sensory evaluation and electronic nose analysis as the evaluation indexes in adjusting the immersion parameters, it was found that soaking at 50 ℃ for 10 minutes had a significant effect on improving the odor of aged indica rice, which was similar to the overall flavor profile of the fresh rice. Compared with the untreated aged rice, the lipase activity of aged rice decreased by 78.2%, the peroxide value dropped to 1.52×10-2 mmol/kg, and the molality of malondialdehyde only increased by 7.5% after soaked at 50 ℃ for 10 minutes. Pre-soaking effectively delayed the hydrolysis and oxidation of lipids in rice grains and reduced the formation of off-flavor compounds during the cooking process of aged indica rice. The results of this study provided a reference for the design and improvement of flavor refreshness curve of aged indica rice cooked in electric cooker.
