fragrance

An aroma compound, also known as odorant, aroma, fragrance or flavor, is a chemical compound that has a smell or odor. A chemical compound has a smell or odor when two conditions are met: the compound needs to be volatile, so it can be transported to the olfactory system in the upper part of the nose, and it needs to be in a sufficiently high concentration to be able to interact with one or more of the olfactory receptors.
Aroma compounds can be found in food, wine, spices, perfumes, fragrance oils, and essential oils. For example, many form biochemically during ripening of fruits and other crops. In wines, most form as byproducts of fermentation. Odorants can also be added to a dangerous odorless substance, like propane, natural gas, or hydrogen, as a warning. Also, many of the aroma compounds play a significant role in the production of flavorants, which are used in the food service industry to flavor, improve, and generally increase the appeal of their products.

Compound name	Fragrance	Natural occurrence	Chemical structure
Methyl formate	Ethereal
Methyl acetate	Sweet, nail polish Solvent
Methyl butyrate Methyl butanoate	Fruity, Apple Pineapple
Ethyl acetate	Sweet, solvent	Wine
Ethyl butyrate Ethyl butanoate	Fruity, Orange Pineapple
Isoamyl acetate	Fruity, Banana Pear	Banana plant
Pentyl butyrate Pentyl butanoate	Fruity, Pear Apricot
Pentyl pentanoate	Fruity, Apple
Octyl acetate	Fruity, Orange

[edit] Linear terpenes

Compound name	Fragrance	Natural occurrence	Chemical structure
Myrcene	Woody, complex	Verbena, Bay
Geraniol	Rose, flowery	Geranium, Lemon
Nerol	Sweet rose, flowery	Neroli, Lemongrass
Citral, lemonal Geranial, neral	Lemon	Lemon myrtle, Lemongrass
Citronellal	Lemon	Lemongrass
Citronellol	Lemon	Lemongrass, rose Pelargonium
Linalool	Floral, sweet Woody, Lavender	Coriander, Sweet basil Lavender
Nerolidol	Woody, fresh bark	Neroli, ginger Jasmine

[edit] Cyclic terpenes

Compound name	Fragrance	Natural occurrence	Chemical structure
Limonene	Orange	Orange, lemon
Camphor	Camphor	Camphor laurel
Terpineol	Lilac	Lilac, Cajuput
alpha-Ionone	Violet, woody	Violet
Thujone	Minty	Cypress, lilac Juniper

[edit] Aromatic

Compound name	Fragrance	Natural occurrence	Chemical structure
Benzaldehyde	Almond	Bitter almond
Eugenol	Clove	Clove
Cinnamaldehyde	Cinnamon	Cassia Cinnamon
Ethyl maltol	Cooked fruit Caramelized sugar
Vanillin	Vanilla	Vanilla
Anisole	Anise	Anise
Anethole	Anise	Anise Sweet basil
Estragole	Tarragon	Tarragon
Thymol	Thyme	Thyme

[edit] Amines

Compound name	Fragrance	Natural occurrence	Chemical structure
Trimethylamine	Fishy Ammonia
Putrescine Diaminobutane	Rotting flesh	Rotting flesh
Cadaverine	Rotting flesh	Rotting flesh
Pyridine	Fishy	Belladonna
Indole	Fecal Flowery	Feces Jasmine
Skatole	Fecal	Feces