Try to count how many genuine fruit essential oils exist. Orange, lemon, pomelo, mandarin, bergamot: all are pressed from the peel, not the flesh. Strawberry, peach, mango and pineapple oils hardly exist at all. Fruit flesh is mostly water and sugar, with very little aroma, and what aroma there is gets destroyed or altered when heated.
So when a perfume says “fruity”, “peach”, “pear” or “tropical fruits”, the note is almost always rebuilt from the molecules that ripe fruit makes itself. This article introduces those molecules.
Three groups of ripeness compounds
Esters: the sweet smell of ripe fruit. As fruit ripens, enzymes join acids and alcohols into esters. That is why unripe fruit barely smells and ripe fruit fills the house.
| Ester | Smells of |
|---|---|
| Isoamyl acetate | Ripe banana, banana sweets |
| Ethyl butanoate | Pineapple, fruit sweets |
| Ethyl hexanoate | Pineapple, ripe apple, slightly winey |
The ripe jackfruit entry in the scent dictionary is the most familiar example: almost its entire smell is esters.
Lactones: the creamy, smooth smell. Lactones are ring-shaped molecules that give an impression of cream and fruit skin without any fat at all.
| Lactone | Smells of |
|---|---|
| γ-Decalactone | Ripe peach |
| γ-Nonalactone | Toasted coconut, cream |
| δ-Decalactone | Cream, coconut, peach |
Peach and apricot notes in perfume almost always rely on lactones. Osmanthus is a rare case: its absolute has a real ripe-apricot note, partly thanks to lactones.
Furanones and relatives: the smell of ripe sugar. Furaneol is the main odorant of ripe strawberry, and also occurs in pineapple and caramelised sugar. Maltol gives a burnt-sugar, baked note. These two are why strawberry notes in perfume always have something of sweets about them.
Beyond these groups are some famous individual compounds: methyl anthranilate for a candy-like grape smell, raspberry ketone for raspberry.
Tropical fruit and sulfur
“Tropical” notes are harder to build. The smell of passion fruit, mango or guava is not only esters but also sulfur compounds present in trace amounts, with extremely low detection thresholds. The passion fruit entry describes that sulfur note: at low concentration it reads as tropical, at high concentration as raw onion. Durian pushes this group to a level many people cannot bear.
Perfumers use these compounds in very small amounts, because a slight excess turns a tropical note into an unpleasant one.
Fruit materials that do exist
There are still a few natural materials with a fruity character:
- Cold-pressed citrus peel: bergamot, lemon, pomelo, mandarin. These are the only “fruit” group with genuine essential oils in common use, and perfumery usually files them separately as citrus.
- Blackcurrant bud absolute (cassis): taken from the buds, not the berries, with a green berry smell and a sulfurous edge.
- Davana: the oil of an Indian wormwood, smelling of dried fruit and apricot, though the plant bears no such fruit.
Reading fruit notes on a box
When a note list says “pear”, “peach” or “red berries”, read it as a description of smell, usually built from esters, lactones and furanones. That does not make the note any lesser: the same molecules are what ripe fruit makes itself. It only means that no pear was distilled to make that perfume.
With essential oils it is the other way round. A bottle labelled “strawberry essential oil” or “mango essential oil” should make you suspicious, because distilling those fruits does not yield an essential oil in the usual way.
Sources
- Ohloff G., Pickenhagen W., Kraft P. (2012). Scent and Chemistry: The Molecular World of Odors. Verlag Helvetica Chimica Acta, Wiley-VCH.
- Schwab W. (2013). Natural 4-hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol®). Molecules 18(6), 6936–6951. doi:10.3390/molecules18066936