Abstract: 【Objective】 Through laboratory simulation of dynamic temperature and humidity conditions, the volatile compositions of rice were studied to find out some characteristic volatiles closely related to the rice quality. The objective of this paper is to provide reference for the construction of dynamic storage and transportation of rice. 【Method】 According to the actual transportation conditions of rice, rice was stored by simulating dynamic temperature and humidity of storage and transportation. Rice samples with 5 moisture contents (14%, 16%, 18%, 20% and 22%) were stored and transported for two months, respectively, at low temperature, middle temperature and high temperature (respectively fluctuates around 10℃, 20℃, and 30℃, humidity fluctuates around 80%). All rice samples were tested by SPME-GC/MS and electronic nose (e-nose) in this study. Principal component analysis (PCA) was used to analyze the data. 【Result】 Under different temperature conditions, the radar graphs of different moisture contents and time of rice all were different. The response values of the same moisture content rice had obvious differences under the different temperature conditions at 15 day. With the time, the differences of 14%-18% moisture contents rice samples reduced. Principal component analysis of e-nose could significantly distinguish all rice samples during storage. There were 275, 262 and 215 kinds of volatile compositions of rice samples including alkanes, olefin or alkyne, aromatic compounds, glycol ether, aldehydes, ketones, acid esters, and heterocyclic were detected, respectively, under low, medium and high temperature conditions, but only 46 kinds of which were detected in the original samples. Alkanes showed a bigger difference under low temperature conditions, and followed by medium temperature, high temperature. Olefin or alkyne, aromatic compounds, glycol ether and heterocyclic showed greater difference with temperature rising, and aldehydes, ketones, acid esters showed the largest difference under medium temperature conditions. With the time, characteristic alkane transformed from straight-chain into cycloalkane under low temperature or moisture content conditions. Haracteristic olefin or alkyne were mainly oxygen-containing or ring-shaped material at the late stage of storage. The 2,6-Di-tert-butyl-4-methylphenol, octyl phenol, and cinnamonitrile were aromatic compounds of fresh rice. With the deterioration of rice quality, methoxy or naphthalene ring materials were main characteristic aromatic compounds in rice. The 2-methyl-1-hexadecanol, benzyl alcohol, decanal, and piperitone were main characteristic glycol ether, aldehydes or ketones and had special fruity or irritating smell. Methyl-2-aminobenzoate, methyl salicylate, dihydroactinidiolide were main characteristic acid esters and had a sweet taste at early stage or under low temperature conditions, and myristic acid, decanoic acid were found at later stage and were tasteless or offensive. Furan, quinolone were characteristic heterocyclic substances with special flavor.【Conclusion】 E-nose could quickly and effectively distinguish rice samples under different moisture contents and temperatures conditions. The types and content of volatile compositions are affected by moisture content and temperature conditions of rice. Low moisture contents of rice (14%-16%) and short-term storage (30 days) are conducive to control the change of volatile compositions, and high moisture contents (20%-22%) could speed up the change of volatile compositions in rice.

Key words: rice, dynamic change of temperature and humidity, volatile matters, electronic nose, SPME/GC-MS