Abstract: The volatile components of steamed pork with rice obtained at 4 different steaming times were investigated by purge and trap thermal desorption (P&T-TD) combined with gas chromatography-mass spectrometry-olfactometry (GC-MS-O). The results showed that a total of 77 volatile compounds were identified, 69, 43, 50 and 56 of which were detected after 0, 30, 60 and 90 min of steaming, respectively. Thirty-three volatile compounds were common to the four samples. The total content of volatile components increased gradually from 1 646.39 to 2 657.10 μg/kg during the process of steaming, and the types of volatile compounds also increased gradually. The analysis of odor activity value (OAV) showed that the contents of all the flavor compounds (OAV > 0.1) increased firstly and then decreased, and the highest OAV value was observed after steaming for 60 min. Furthermore, methyl nonaldehyde, decyl aldehyde and methyl cinnamate made the greatest contribution to the characteristic flavor of streamed pork with rice. Principal component analysis (PCA) showed that the 60 min steamed sample was clearly discriminated from other samples and exhibited a greater cumulative variance contribution rate of the first and second principal components. In summary, better flavor of the product was obtained after steaming for 60 min.

Key words: steamed pork with rice, flavor, purge and trap thermal desorption, principal component analysis, gas chromatography-mass spectrometry coupled with olfactometry (GC-MS-O)