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The unique flavor of Beijing Youji (BJY) chicken broth compared with that of commercial broilers (CB) was investigated by solvent-assisted flavor evaporation combined with AEDA/GC-O (aroma extract dilution analysis of gas chromatography-olfactometry), quantitation, and aroma recombination. A total of 71 odorants with almost the same major odorants (≥10 ng/g broth) were found by GC-O in both BJY and CB broths. However, BJY broth had thirty-two more extra odorants than CB broth, indicating the rich fragrance of the former. Aroma recombination and omission experiments demonstrated that 21 versus 17 odorants (with OAV ≥ 1) contributed significantly to BJY and CB broth aromas, respectively. Those key odorants mainly included sulfur-containing compounds and aliphatic aldehydes, such as 2-methyl-3-furanthiol, 3-(methylthio)propanal, ( E, E)-2,4-decadienal, etc. Furthermore, composition analysis of the meat suggested that the better flavor, with rather more odorants, of BJY broth is probably due to higher contents of polyunsaturated fatty acids and water-soluble flavor precursor, including ribose, cysteine, thiamine, etc., present in the BJY meat.

Shanxi aged vinegar is one of the most famous Chinese traditional cereal vinegars produced by spontaneous solid-state fermentation. However, the aroma composition of Shanxi aged vinegar is still ambiguous. The Shanxi vinegars before and after aging were both analyzed by solvent-assisted flavor evaporation combined with gas chromatography-mass spectrometry (GC-MS) as well as gas chromatography-olfactometry (GC-O) in aroma extract dilution analysis. A total of 87 odor-active regions were found by GC-O, and 80 odor-active compounds were identified. By GC-MS/MS, in selected reaction monitoring mode, 30 important identifications were quantitated using authentic standards. In comparison, the aroma molecules for the vinegars before and after aging were almost the same; only their levels were altered, with mostly the esters and some compounds that produce pungent smells being lost and the levels of those from the Maillard reaction, especially the pyrazines (e.g., tetramethylpyrazine), being greatly increased. As for the aged vinegar, the compounds found to have high flavor dilution factors (>128) were 3-(methylthio)propanal, vanillin, 2,3-butanedione, tetramethylpyrazine, 3-methylbutanoic acid, γ-nonalactone, guaiacol, 3-(methylthio)propyl acetate, dimethyl trisulfide, phenylacetaldehyde, 2-ethyl-6-methylpyrazine, 2-acetylpyrazine, 2,3-dimethylpyrazine, furfural, and 3-hydroxy-2-butanone. However, the aroma compounds found at high concentrations (>25 μg/L) in the aged vinegar were acetic acid, followed by 2,3-butanedione, furfural, 3-hydroxy-2-butanone, tetramethylpyrazine, furfuryl alcohol, and 3-methylbutanoic acid.

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Volatile composition of Chinese traditional smoke-cured bacon of Mini-pig breed was first characterized. Both headspace solid phase microextraction (SPME) and simultaneous distillation and solvent extraction (SDE) were performed. SDE exhibited efficiency in the extraction of representative aromatic volatiles especially the phenolic smoky flavors from the bacon sample. In total, 104 different components were found with the major quantity and kinds of aromas being the volatile saturated and unsaturated aldehydes from lipid oxidation and the phenolic compounds from smoke. Olfactory evaluation (GC-O) of the SDE extract revealed five basic odor patterns pertaining to 53 odor active regions and 47 odorants. Some key flavors accounting for the bacon aroma were (E, E)-2, 4-decadienal, 3-(methylthio) propanal, 2-furanmethanol, guaiacol, 3-ethylphenol and 2, 5-dimethylpyrazine.