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As test materials, Rongchang pork and cut into 1cm thick bars at 180 ℃ baking 15min, 30min, 40min its center temperature reached 60 ° C, 80 ° C, 90 ° C. Flavor precursors and the variation of the physical and chemical indicators in the research process, and to study the changes of the olfactory sense of the major class of volatile flavor substances in the process. In addition, using an electronic nose to distinguish between the overall flavor of the processed samples using partial least squares regression statistical methods to explore the main flavor substances of the differences in the two extraction methods of distillation and solvent extraction and solid phase micro extraction and processing stage, a certain sense, to improve our traditional specialty food processing also provides for a similar study of some of the main ideas and methods. The results showed that: 1. Better extraction of low boiling compounds solid phase micro extraction, while distillation and extraction method of extraction of high-boiling compounds better. Distillation and Extraction Method process of heat treatment for a long time, can lead to the degradation of the flavor compounds to produce other compounds. Distillation and Extraction Method flavor substances tend to deviate from the essence of flavor extracts cause some semblance of flavor generation. Two extraction methods complement each other better analysis for barbecue volatile flavor substances. Process changes in the physical and chemical indicators: 180. C processing, respectively, 15min, 30min, 40min, the center of the sample temperature reached 60 ° C, 80 ° C and 90 ° C; moisture content declining 59.24%, 43.77%, 30.82% respectively; 5.75,5.78 and 5.84 pH does not change significantly ; TBA values ??showed a trend first and then decreased, respectively 1.67,2.09 and 1.18; crude fat content was constantly decreased 13.73%, 11.71% and 11.41%; crude protein content was significantly decreased, respectively, 56.09%, 43.22% and 35.61%, respectively. Processing body substance before the flavor changes: (1) reducing sugar: processing center temperature rising, reducing sugar content decreased gradually reducing sugar content processing 30min ~ 40min stage the decreasing trend slowed. (2) Thiamine: heating temperature in the initial stage of the processing is not very high heating time is not the trend of decrease in the content of the long thiamine is relatively slow, with the extended sample of the heating temperature and the heating time of thiamine hormone content was significantly reduced. (3) The free amino acid: seventeen amino acids in the total amount of processing is showing a declining trend, including methionine, cysteine, proline, hydroxyproline, threonine, serine and lysine changes significantly, the thermal degradation of these amino acids is one of the important ways to lead to a significant increase in the pyrazine compounds, pyridine compounds and sulfur-containing compounds in the samples. (4) a fatty acid composition: composition of the triglycerides of saturated fatty acids and monounsaturated fatty acids in the process percentage content did not change significantly, composed of the percentage content of the multi-unsaturated fatty acids of the triglyceride changes significantly; processing phospholipid parts of degradation occurred, wherein the saturated fatty acids and single unsaturated fatty acid degradation was not significant, but the mono-unsaturated fatty acid C16: 1 fatty acid linoleic acid changes significantly; general variation tendency of the free fatty acids is significantly elevated MUFA SFA change no significant PUFA significantly reduced, especially baking 40min when Rongchang pig samples, PUFA reduce particularly remarkable. 4 process major flavor olfactory sense the change of substance: the various stages in the processing of aldehydes has been highest percentage content of a class of volatile flavor compounds 2 - butenal, 3 - methylbut-aldehyde and The percentage content of the benzaldehyde during processing is significantly increased. In addition, furan and their derivatives, pyrazine compounds, sulfur compounds and the content of the lactone compound in the sample with a higher degree of processing is a significant increase, the largest contribution olfactory sense substances Rongchang pork baking processed flavor. Other compounds such as an alcohol compound, a ketone compound, the acid compound, ester compound and aromatic compound in the meat in the threshold value is high, although they have a high concentration but they Grill flavor contribution is very small, and processing changes in the compound is not the law. 5. Main flavor substances after processing: processing the sample after the electronic nose distinguish found little after 30min and 40min after baking processing Samples E and F the overall flavor message differences (Rongchang pork material) and Sample A and Sample C ( 15min baking) of the overall flavor of the sample after processing message differences. Partial least squares regression analysis, the overall flavor of processed Rongchang pork baked products the largest contribution to the olfactory sense of substance: 2,3 - dimethyl pyrazine, 2,5 - dimethyl pyrazine, 2 - ethyl-6 - methyl pyrazine, trimethyl pyrazine, disulfide, dimethyl disulfide, dimethyl trisulfide, di furfuryl disulfide.
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