The Grassy, Fresh section of the Revised Scottish Whisky Flavour Wheel mentions “Wet Cut Grass” as a congener. Since grass is basically a leaf please also read the “leafy” section of this congeners page first.
The kind people of the Good Scent Company made a “Grassy” page holding al the chemicals that have a grassy smell. On this page many chemicals are mentioned for the “grassy” smell and Hexanal and Hexanol are also on this page.
I found a paper [see reverence 1] on the mechanism used by plants to produce the grassy smell one smells when wet grass is cut. It turns out that the chemicals produced are meant to protect the cut ends of the grass. A liquid bandaid so to speak. This paper also details many chemicals that, in different combinations, produce the smell of a banana, or an apple.
“Green odour of green leaves arises from a mixture of the eight volatile C6-compounds. The ratio of C9 to C6 is characteristic for each fruit species, e.g., in banana, 90% is C9_and 10% is C6-compounds” (Hatanaka et al., 1975).
Chemicals mentioned in the article have 6 or 9 carbons:
- (3Z)-Hexenol, which is commonly called leaf alcohol, and,
- (2E)-Hexenal, also called leaf aldehyde, which are both widely distributed in fresh leaves, vegetables and fruits
- (3E)-, and (2E)-hexenols,
- (3Z)-, and (3E)-hexenals, https://en.wikipedia.org/wiki/Cis-3-Hexenal
- (3Z, 6Z)-, (2E, 6Z)-nonadienols, and their corresponding aldehydes
- (3Z)-, (2E)- nonenols, and their corresponding aldehydes
Hexanal has an odor desciption on pubchem which reads
“Characteristic fruity odor (on dilution), Strong, green grass odor, Sharp, aldehyde odor”
The idea is that different plants, like grass, produce different mixtures and concentrations of these chemicals and combined create the characteristic smell of “Cut Grass” or “Banana” or “Melon”.
So in short, the smell of “Cut Grass” comes from a selection of Hexanol and Hexanal chemical compounds, depending on the mixture and concentration of these chemical compounds.
- The Biogeneration of Green Odour by Green Leaves and It’s Physiological Functions – Past, Present and Future, Akikazu Hatanaka, Tadahiko Kajiwara and Kenji Matsui Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan,Z. Naturforsch. 50c, 467-472 (1995); received December 9, 1994/March 1, 1995 Green Odour, Lipoxygenase, Fatty Acid Hydroperoxide Lyase