2-butenal

green aldehyde

Found in 15 ingredients across the CompKitchen flavor graph.

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

2D Lewis Structure

Formula: C4H6O
Molecular weight: 70.09 g/mol
PubChem CID: 447466 — full record on PubChem

Properties

Odor description: pungent, green, fruity, sweet
Odor threshold — in a food matrix: 32.9 ppb 1 published value · see all 3 with sources
Volatility: high
CAS number: 4170-30-3
Retention index: 905

Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

? Partial match

FEMA number: 3224
GRAS publication: GRAS 4
FEMA primary name: 2-PHENYL-2-BUTENAL

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

Source: FEMA GRAS publications 1-33. 4 related FEMA records for this name — verify the exact substance for regulatory use.

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.

Also filed as

crotonaldehyde

Same molecule, unified here — previously counted and displayed as separate compounds.

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.

pine FlavorDB 2.0, Flavordb Odor Column 2 sources agree

fruity FlavorDB 2.0, Flavordb Odor Column 2 sources agree

butter, camphor, chemical FlavorDB 2.0

pungent, green, fruity, sweet shown above Llm Adjudicated

—

chemical Flavordb Odor Column

—

butter Flavordb Odor Column

—

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

3 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.

In a food matrix

32.9 ppb

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

Threshold	Matrix	Source	Paper
32.9 ppb	water (food: unknown)	Literature corpus	—

In air

1.0 ppb – 23.0 ppb

Airborne detection — not comparable to a water threshold.

Threshold	Matrix	Source	Paper
1.0 ppb	air	PMC open access	—
23.0 ppb	air	Nagata 2003	—

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 (49.94 ppb, the engine's canonical value — see the 3 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
extra virgin olive oil	8000.0	160 ⚡	—
peanut	1730.0	34.6 ⚡	—
liver	430.0	8.61	—

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 2-butenal. 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 2-butenal in it. Full concentrations are in the OAV table above.

268 cmpds

75 cmpds

81 cmpds

201 cmpds