Multidimensional Gas Chromatography of Organosulfur Compounds in Coffee and Structure-Odor Analysis of 2-Methyltetrahydrothiophen-3-one.

Aileen Pua, Yunle Huang, Rui Min Vivian Goh, Kim-Huey Ee, Lingyi Li, Maurin Cornuz, Benjamin Lassabliere, Lionel Jublot, Shao Quan Liu, Bin Yu

Journal of agricultural and food chemistry 2023 Mar 15

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Organosulfur compounds (OSCs) in coffee remain challenging to analyze by conventional gas chromatography (GC) due to their low concentrations amid coffee's complex matrix and susceptibility to chiral-odor influences. In this study, multidimensional GC (MDGC) methods were developed to profile OSCs in coffee. Conventional GC was compared to comprehensive GC (GC×GC) for untargeted OSC analysis in eight specialty coffees, and GC×GC was found to improve the fingerprinting of OSCs in coffee (50 vs 16 OSCs identified). Of the 50 OSCs, 2-methyltetrahydrothiophen-3-one (2-MTHT) was of high interest due to its chirality and known aroma contribution. Following that, a heart-cutting method for chiral GC (GC-GC) was developed, validated, and applied to the coffees. The mean enantiomer ratio of 2-MTHT was observed to be 1.56 (R/S) in brewed coffees. Overall, MDGC techniques allowed for more comprehensive analyses of coffee OSCs, from which (R)-2-MTHT was found to be the predominant enantiomer with the lower odor threshold.

Citation

Aileen Pua, Yunle Huang, Rui Min Vivian Goh, Kim-Huey Ee, Lingyi Li, Maurin Cornuz, Benjamin Lassabliere, Lionel Jublot, Shao Quan Liu, Bin Yu. Multidimensional Gas Chromatography of Organosulfur Compounds in Coffee and Structure-Odor Analysis of 2-Methyltetrahydrothiophen-3-one. Journal of agricultural and food chemistry. 2023 Mar 15;71(10):4337-4345