Effects of Temperature on Volatile Profile and Aroma Quality in Rice

Aroma is an important grain quality trait of aromatic rice, controlled by a recessive gene which increases the accumulation of numerous volatile compounds to produce it. The aroma quality of rice grain also depends on the cultivation practice, genetic condition, environmental components and their interaction. Among the environmental components, the temperature is the vital component that can affect the aroma quality and chemical composition of aromatic rice. This study assessed the effects of different temperatures (ambient or 28C, 25C and 20C) for the volatile profile and aroma quality of five aromatic and a nonaromatic rice genotypes by gas chromatography-mass spectrometry (GC-MS), gas chromatography-flame ionization detector (GC-FID) and organoleptic test. The results indicated that the aromatic rice genotypes contained more volatile compounds (15 compounds) and displayed the maximum aroma score (Score 4) at the 25C temperature than ambient and 20C temperature. The obtained information will be helpful for exploring possible reasons for variation in the biochemical composition as well as aroma quality of a genotype which might be used to improve grain quality of aromatic rice.