Effects of Storage with a Deoxygenating Agent and a Nitrogen-atmosphere Package on the Quality, Especially Flavor, of Cooked Stored Rice

To investigate the effect of a deoxygenating agent (deoxy) and a nitrogen-atmosphere package (nitro) on the quality, especially flavor, of Koshihikari stored at 30 degrees C for 12 months, volatile compounds of the cooked stored rice were analyzed by gas chromatography-olfactometry (GC-O), GC-mass spectrometry and sensory evaluation. Sensory evaluation revealed that the deoxy-rice was very similar in quality to non-stored rice (fresh-rice), although the non-treated stored rice (control-rice) and nitro-rice had a stale flavor and undesirable taste. Furthermore, GC-O analysis indicated that the number of volatile compounds in the deoxy- and fresh-rice was significantly less than in the control- and nitro-rice. Therefore, it was suggested that the technique of storing harvested rice with a deoxygenating agent could maintain the flavor of harvested rice at room temperature.