Identification of compounds responsible for the characteristic “soy sauce” flavor of traditional Chinese liquor

Soy sauce aroma liquor is one of the most popular types of traditional liquors in China, with the annual commercial value as high as 8.2 billion USD. The most famous soy sauce aroma liquor is the Chinese national liquor Moutai (MT), which was first developed around 206 BC. The flavor of MT is unique and highly appreciated by both experts and consumers. It received gold awards at the 1915 San Francisco “World's Fair” and at the 12th International Food Fair in Paris in 1986, which is testimony to the outstanding flavor and premium quality of this liquor product. However, significant as it is economically and culturally to China, knowledge about the characteristic flavor profile of MT is quite limited. Many scientists have studied this topic for decades and raised several hypotheses with respect to the compounds that are responsible for MT’s unique and characterizing flavor. However, despite much effort the compounds actually responsible for the characterizing “soy sauce” aroma of soy sauce aroma liquors are still unknown. The lack of this information has hindered the optimization of the brewing and blending technology to achieve liquors with better and more consistent aroma profiles. This research aims to identify the key and characterizing odorants in soy sauce aroma liquor in the case of MT. Through the use of advanced separation and analytical methods, 143 odor-active components were detected. The relative potencies of the odorants were assessed by gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). Based on the results of AEDA, the most potent odorants in MT were: acetal; ethyl 2-methylpropanoate; ethyl butanoate; ethyl 2-methylbutanoate; ethyl 3-methylbutanoate; ethyl pentanoate; ethyl 2-methylpentanoate; ethyl 4-methylpentanoate; isopentyl hexanoate; β-damascenone and ethyl phenylpropionate, 2-phenylethanol, 3-methybutanal, 2-methyl-3-furanthiol, 2-methyl-3-(methyldithio)furan, dimethyl trisulfide and 3-hydroxy-4,5-hydroxy-2(5H)-furanone (sotolon). Four sulfur-containing odorants which might provide “savory” top notes to the flavor of MT were identified as 2-methyl-3-furanthiol (MFT), 2-methyl-3-(methyldithio)furan (MFT-MT), 2-furfurylthiol, and bis(2-methyl-3-furyl) disulfide (MFT-MFT). To the best of our knowledge, MFT, MFT-MT and MFT-MFT have not been previously identified in Moutai or any other type of Chinese soy sauce aroma liquor.LimitedAuthor requested closed access (OA after 2yrs) in Vireo ETD syste