Milled Rice Oxidation Volatiles and Odor Development

ABSTRACT The development of volatile components in milled rice was investigated over 50 d of storage. The major volatiles were identified and measured by gas chromatography‐mass spectrometry and their relative odor potencies were subsequently calculated as aroma values. Volatile concentrations were greater in partially milled rice than in fully milled rice. Concentrations of 2‐nonenal, octanal, and hexanal increased significantly during storage whereas heptanal, 3‐penten‐2‐one, and 2‐pentylfuran did not. Octanal (fatty) and 2‐nonenal (rancid) had the highest contributions to milled rice odor. The aroma values for hexanal and 2‐pentylfuran changed by a larger factor relative to those for heptanal, 2‐nonenal, 3‐penten‐2‐one, and octanal during early storage, whereas the aroma value for 2‐nonenal increased by a higher factor than those obtained for the other components during late storage. Hexanal and 2‐pentylfuran had the highest influence on odor change at the beginning of storage, whereas 2‐nonenal influenced odor change.