Identification and Characterization of Sulfur Heterocyclic Compounds That Contribute to the Acidic Odor of Aged Garlic Extract

The aroma of aged garlic extract (AGE) has been recently characterized as a complexity of seasoning-like, metallic, fatty, and acidic notes; most of the important aroma compounds were identified in a previous study. Besides the 25 previously identified aromas of AGE, several of the odor compounds that contribute to the acidic notes were isolated and identified using various analytical techniques, including gas chromatography coupled with an olfactometry monitoring system (GC-O), accurate and high-performance preparative GC system, GC-MS analysis, and sensory evaluation. The identified aromas include: 2,4-dimethyl-1,3-dithiolane, 2,5-dimethyl-1,4-dithiane, and 2,6-dimethyl-1,4-dithiane. Interestingly, AGE contains all stereoscopic isomers of each of these components. An aroma recombinant composed of the newly identified acidic odors with other key odorants showed good agreement with the aroma of AGE.