High concentrations of aldehydes tend to be very pungent and overwhelming, but low concentrations can evoke a wide range of aromas.
* Acetaldehyde (ethereal)
* Hexanal (green, grassy)
* cis-3-Hexenal (green tomatoes)
* Furfural (burnt oats)
* Hexyl cinnamaldehyde
* Isovaleraldehyde – nutty, fruity, cocoa-like
* Anisic aldehyde – floral, sweet, hawthorn. It is a crucial component of chocolate, vanilla, strawberry, raspberry, apricot, and others.
* Cuminaldehyde (4-propan-2-ylbenzaldehyde) – Spicy, cumin-like, green