3-hexenal

green aldehyde Key food odorant

Found in 29 ingredients across the CompKitchen flavor graph.

Look up another compound — search by name, CAS number, PubChem CID, or FEMA #.

2D Lewis Structure

Formula: C6H10O
Molecular weight: 98.14 g/mol
PubChem CID: 643139 — full record on PubChem

Key food odorant (intermediary)

Dunkel et al. 2014

Identified in the meta-analysis of 227 food samples as one of 57 intermediary odorants — appears in 5–25% of foods. Characteristic odor: green, grassy.

Source: Angew. Chem. Int. Ed. 2014, 53, 7124–7143

Properties

Odor description: apple, fruity, green, leafy, melon, natural, stem, tomato
Odor threshold — orthonasal, in clean water: 0.250 ppb 1 published value · see all 9 with sources
Volatility: high
CAS number: 4440-65-7

Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

✓ Exact match

FEMA number: 3923
GRAS publication: GRAS 19
FEMA primary name: 3-HEXENAL

Use-level matrix not extracted for this substance — check the source publication for current ppm guidance.

Source: FEMA GRAS publications 1-33.

How this molecule is described

Sources disagree about odour more often than they disagree about chemistry. Rather than show one answer, here is every description on file with how many ingredient records carry it.

Descriptions on file

Ordered by how many independent descriptor streams give each wording, then by how often it appears. The bar is still replication — one source copied onto many ingredients scores high there — so the two can disagree.

corn FlavorDB 2.0, Flavordb Odor Column 2 sources agree

chemical FlavorDB 2.0, Flavordb Odor Column 2 sources agree

apple, fruity, green, leafy, melon, natural, stem, tomato shown above FlavorDB 2.0

Sharp, green, grassy FlavorDB 2.0

green odor FlavorDB 2.0

green, grassy FlavorDB 2.0

Bars are the share of ingredient records carrying each description. High agreement means the sources replicate each other — not necessarily that they are right.

Published thresholds

9 measured values from the literature. Grouped by what was actually measured — a threshold smelled in clean water, tasted in the mouth, or measured in a real food are three different quantities and are not pooled.

Orthonasal, in clean water

0.250 ppb

The reference measurement — smelled in water. OAV is computed against this.

Threshold	Matrix	Source	Paper
0.250 ppb SIDA	water	Rychlik 1998 · 1 studies	—

In a food matrix

0.120 ppb – 0.250 ppb

Measured in a real food, where the matrix shifts detection — not a clean-water value.

Threshold	Matrix	Source	Paper
0.120 ppb SIDA	water (food: pink guava)	Literature corpus	29868555, 40366211, 41019745
0.210 ppb SIDA	water (food: reference standard (water))	Literature corpus	29868555, 40366211, 41019745
0.250 ppb SIDA	water (food: hand-squeezed grapefruit juice)	Literature corpus	29868555, 40366211, 41019745
24606 ppb SIDA	water (food: unknown)	Literature corpus	29868555, 40366211, 41019745
Flagged: 106983× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.

Retronasal / in-mouth

0.030 ppb – 1.2 ppb

Tasted rather than smelled — a different sense, not comparable.

Threshold	Matrix	Source	Paper
0.030 ppb SIDA	water_retronasal	Rychlik 1998 · 1 studies	—
1.2 ppb SIDA	oil_retronasal	Rychlik 1998 · 1 studies	—

Other matrix

1.7 ppb – 2.0 ppb

Measured in a non-aqueous medium (oil, starch, cellulose).

Threshold	Matrix	Source	Paper
1.7 ppb SIDA	oil_orthonasal	Rychlik 1998 · 1 studies	—
2.0 ppb SIDA	cellulose	Rychlik 1998 · 1 studies	—

Only values we can attribute are listed. Where a compendium's licence does not permit public attribution its figures are omitted here, so every number on this page traces to a citable source.

Where you'd actually smell it

Odor Activity Value = measured concentration ÷ odor threshold (0.25 ppb, the engine's canonical value — see the 9 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
fennel	100000.0	400000 ⚡	—
horseradish	25100.0	100400 ⚡	—
olive	20000.0	80000 ⚡	DOI
extra virgin olive oil	11000.0	44000 ⚡	Corpus paper
olive oil	3880.0	15520 ⚡	Corpus paper
orange	2680.0	10720 ⚡	DOI

Concentrations from PubMed Central Open Access papers (free literature corpus, MIT-style licensed). Copper = OAV ≥ 10 (strongly perceptible). Green = OAV ≥ 1 (perceptible).

Found in

Measured impact first, then profile share

Every ingredient known to contain 3-hexenal. Ingredients with a measured concentration come first, ranked by odour activity; the rest follow by how large a share of that ingredient's profile this molecule is. The figure beside each is how many different compounds that ingredient has in total — not the concentration of 3-hexenal in it. Full concentrations are in the OAV table above.

olive

measured · OAV 80000.0

370 cmpds

orange

measured · OAV 10720.0

472 cmpds

198 cmpds

208 cmpds