1.School of Food Science and Technology,Jiangnan University,Wuxi;2.Foshan Shunde Midea Electic Appliance Manufacturing Co,Ltd,Foshan
电饭煲热处理可通过物理方式提升米饭的风味，但其在改善陈米风味方面还缺少相应模式。采用气-质联用结合风味阈值鉴定得到对米饭陈味具有重要贡献的挥发性风味物质为己醛、辛醛、壬醛和癸醛。以感官评定和电子鼻分析作为评价指标，通过调控浸泡参数发现50°C处理10 min对籼陈米饭气味具有明显的改善作用，并与新米饭整体风味轮廓较为接近。与未浸泡的陈米相比，经50°C处理10 min后，米粒中脂肪酶活力降低了78.2%，过氧化值下降至3.04×10-2 meq/kg，丙二醛质量摩尔浓度仅升高7.5%。预浸泡有效地延缓了米粒中脂质的水解和氧化，减少籼陈米饭烹饪过程中不良风味物质的生成。本研究结果为电饭煲烹饪籼陈米饭风味复鲜曲线的设计与改良提供了借鉴。
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. By using gas chromatography-mass spectrometry combined with flavor threshold analysis, it was identified that the crucial flavor compounds contributing to the stale odor of rice were hexanal, octanal, nonanal and decanal. With sensory evaluation and electronic nose analysis as evaluation indexes, it was found that soaking at 50°C for 10 minutes had a significant effect on improving the odor of the 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 3.04×10-2 meq/kg, and the molality of malondialdehyde only increased by 7.5% after being soaked at 50°C 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 the curve to refresh the flavor of aged indica rice cooked in electric cooker.