熟制、高压灭菌和复热对粉蒸肉挥发性风味物质的影响

采用固相微萃取-气相色谱-质谱-嗅闻仪联用测定加热、高压灭菌、复热后粉蒸肉中的挥发性化合物的种类及含量。结果表明，共测定出40 种挥发性化合物，其中18 种在所有组中均有检出。高压处理后样品中挥发性物质含量（C组2 026.40 μg/kg；D组1 978.77 μg/kg）显著高于未经处理组（A组705.00 μg/kg，B组1 038.53 μg/kg），但微波复热组除外（E组989.12 μg/kg）。气味活度值分析显示己酸乙酯和醛类物质可能是导致“过熟味”、“罐头味”等不良风味产生的主要原因。主成分分析（principal component analysis，PCA）显示各组间分离良好，除微波组外其他组在PC1上贡献差异较小，但在PC2上差异较大；微波组在PC1上贡献低于其他组，在PC2上与高压灭菌组差异不大。总体来看控制醛类物质以及己酸乙酯有助于抑制粉蒸肉高温灭菌及复热产生的不良风味，微波复热对产品风味的不良影响较小。

Effect of Cooking,Autoclaving and Reheating on the Volatile Components of Steamed Pork with Rice Flour

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.