FEMA 3377

Chemical properties

Nona-2-trans-6-cis-dienal is a clear colorless to pale yellow liquid that has an odor reminiscent of green cucumber. The organoleptic character of this compound is attributed almost entirely to olfactory sensations. May be obtained from the steam distillation of fresh cucumber.

Occurrence

Reported as naturally occurring in violet leaves and flowers, in cucumber, sweet and sour cherry, guava, peas, tomato, potato, bell pepper, wheat bread, rye bread, milk, milk powder, fish and fish oil, roast chicken, guinea hen, beef, beer, coffee, tea, oats, mango, kelp, prickly pear, malt, dried bonito, endive, oysters, clam and mate.

The Uses of FEMA 3377

trans-2,cis-6-Nonadienal is an unsaturated aldehyde that is responsible for the cucumber smell of Synura petersenii, a freshwater colonial flagellate. trans-2,cis-6-Nonadienal is also a common natural and drinking water contaminant.

Definition

ChEBI: (2E,6Z)-nona-2,6-dienal is an enal that is (2E,6Z)-nona-2,6-diene substituted by an oxo group at position 1. It has a role as a plant metabolite. It is an enal and a trans-2,3-unsaturated fatty aldehyde.

Preparation

From natural hexenol

Aroma threshold values

Detection: 0.01 ppb

Taste threshold values

Taste characteristics at 10 ppm: green, melon, cucumber-like with an aldehydic nuance

Synthesis Reference(s)

The Journal of Organic Chemistry, 38, p. 36, 1973 DOI: 10.1021/jo00941a008

General Description

trans-2,cis-6-Nonadienal is the key contributor to the cucumber flavor. It is also found in mango ripened anchovy and kelp. Unialgal cultures of various Synurophycean species for the occurrence of trans-2,cis-6-nonadienal have been investigated.

Safety Profile

Low toxicity by ingestion and skin contact. A moderate skin irritant. When heated to decomposition it emits acrid smoke and irritating fumes.