Aroma Constituents in Shanxi Aged Vinegar before and after Aging was written by Liang, Jingjing;Xie, Jianchun;Hou, Li;Zhao, Mengyao;Zhao, Jian;Cheng, Jie;Wang, Shi;Sun, Bao-Guo. And the article was included in Journal of Agricultural and Food Chemistry in 2016.Recommanded Product: 2,4,5-Trimethyloxazole This article mentions the following:
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 chromatog.-mass spectrometry (GC-MS) as well as gas chromatog.-olfactometry (GC-O) in aroma extract dilution anal. 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 mols. 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, di-Me 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 alc., and 3-methylbutanoic acid. In the experiment, the researchers used many compounds, for example, 2,4,5-Trimethyloxazole (cas: 20662-84-4Recommanded Product: 2,4,5-Trimethyloxazole).
2,4,5-Trimethyloxazole (cas: 20662-84-4) belongs to oxazolidine derivatives. Oxazolidines are commonly obtained by reaction of strained heterocycles, mainly aziridines. Oxazolidines are cyclic condensation products of β-amino alcohols and aldehydes or ketone, and they undergo a facile and complete hydrolysis in aqueous solution. Alterations in carbonyl moiety control the rate of formation of a given β-amino alcohol.Recommanded Product: 2,4,5-Trimethyloxazole
Referemce:
Oxazolidine – Wikipedia,
Oxazolidine | C3H7NO – PubChem