关键词: 粉蒸肉, 风味, 固相微萃取, 主成分分析, 气相色谱-质谱-嗅闻仪联用

Abstract: The volatile flavor components in steamed pork with rice flour sampled at different processing stages (cooking and autoclaving) and after reheating were extracted and identified by solid phase micro-extraction (SPME) combined with gas chromatography-mass spectrometry-olfactometry (GC-MS-O) in order to understand the formation of its flavor. A total of 40 volatile compounds were identified, eighteen of which were common to the uncooked (A), cooked (B), autoclaved (C), hot water-reheated (D) and microwave-reheated (E) samples. The content of volatile substances in all autoclaved samples (2 026.40 and 1 978.77 μg/kg for samples C and D) except for sample E (989.12 μg/kg) was significantly higher than that of the unautoclaved samples A (705.00 μg/kg) and B (1 038.53 μg/kg). Odor activity values (OAVs) showed that ethyl caproate and aldehydes may be mainly responsible for the unpleasant overcooked and can-like flavors. Principal component analysis (PCA) showed obvious separation between the five groups. All groups except the microwave-reheated one exhibited a remarkable difference in the contribution of the second principal component (PC2) but not the first principal component (PC1). The contribution of PC1 in the microwave-reheated group was lower than that of the other groups, whereas there was little difference in the contribution of PC2 between the microwave-reheated and autoclaved groups. Overall, controlling the formation of aldehydes and ethyl hexanoate helps to inhibit the formation of off-flavors caused by autoclaving and reheating in steamed pork with rice flour and microwave reheating has little effect on the flavor.

Key words: steamed pork with rice flour, flavor, solid phase micro-extraction, principal component analysis, gas chromatography-mass spectrometry coupled with olfactometry (GC-MS-O)