|   | 
| Primary (First) - gassy | 
| FL |  | diethyl disulfide | 
|  | odor: gassy ripe onion greasy garlic | 
|  | flavor: gassy onion | 
| FL | 2- | ethyl-5-methyl furan | 
|  | odor: fresh gassy burnt | 
| FL | (±)-2- | mercapto-5-methylheptan-4-one | 
|  | odor: gassy, tropical, grapefruit, muscat grape, grapes on the vine | 
|  | flavor: mushroom, meaty, roasted, nutty, toasted, and hazelnut | 
|   | 
| Secondary (Second) - gassy | 
| FL | sec- | amyl mercaptan | 
| FL | 3- | pentane thiol | 
|  | odor: sulfurous gassy durian fruity roasted savory | 
|  | flavor: meaty brothy | 
| FL/FR |  | propyl mercaptan | 
|  | odor: cabbage natural gas sweet onion | 
|  | flavor: alliaceous fresh meaty onion sulfurous | 
|   | 
| Tertiary (Third) - gassy | 
| FL | iso | propyl mercaptan | 
|  | odor: strong ripe onion gassy meaty sulfurous | 
|  | flavor: Soft-boiled egg yolk, hydrogen sulfide, rich mouth feel, strong poultry, leek and onion-like | 
|   | 
| Quaternary (Fourth) - gassy | 
| FL | 2- | hexyl thiophene | 
|  | odor: floral fruity gassy green meaty | 
| FL | 3- | mercapto-2-butanone | 
|  | odor: sulfurous onion roasted gassy meaty | 
|  | flavor: Roasted meat, sulfurous and alliaceous with nuances of cabbage, coffee and pot roast with fatty drippings | 
|   | 
| Quinary (Fifth) - gassy | 
| FL |  | allyl thiopropionate | 
|  | odor: Fresh onion garlic-like with green gassy nuances | 
|  | flavor: Fresh onion with a green sweet vegetable nuance | 
|   | 
| Senary (Sixth) - gassy | 
| FL/FR | (Z)-4- | hexen-1-ol | 
|  | odor: green cooked vegetable tomato cooked turnup brothy gassy | 
|  | flavor: Green, tomato, fresh with herbal vegetable nuances | 
|   | 
| Septenary (Seventh) - gassy | 
|   | 
| Octonary (Eighth) - gassy |