acetaldehyde

green aldehyde Key food odorant

Found in 453 ingredients across the CompKitchen flavor graph.

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

2D Lewis Structure

Formula: C2H4O
Molecular weight: 44.05 g/mol
PubChem CID: 177 — full record on PubChem

Key food odorant (generalist)

Dunkel et al. 2014

Identified in the meta-analysis of 227 food samples as one of 16 generalist odorants — appears in >25% of foods, typically from generic Maillard, lipid-oxidation, or fermentation pathways. Characteristic odor: fresh, fruity.

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

Properties

Odor description: pungent, ethereal, fruity
Odor threshold — orthonasal, in clean water: 15.0 ppb – 67.5 ppb median 25.0 ppb · 3 published values · see all 22 with sources
Volatility: high
CAS number: 75-07-0
Retention index: 604

Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

✓ Exact match

FEMA number: 2003
GRAS publication: GRAS 3
FEMA primary name: ACETALDEHYDE

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

Source: FEMA GRAS publications 1-33. 1 related FEMA record 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

acetaldehyde*

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.

pungent, ethereal, fruity shown above Flavornet Cas, Flavornet Name, Flavordb Odor Column 3 sources agree

—

Pungent, fresh, aldehydic, refreshing and green FlavorDB 2.0

415

aldehydic, ether, ethereal, fruity, pungent, whiskey FlavorDB 2.0

pungent, green apple FlavorDB 2.0

modulates aroma and nasal chemesthesic properties, at low levels positive roles, at higher levels enhances green vegetable notes and itching character FlavorDB 2.0

honey aroma 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

22 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

15.0 ppb – 67.5 ppb

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

Threshold	Matrix	Source	Paper
15.0 ppb SIDA	water	Rychlik 1998 · 3 studies	—
25.0 ppb SIDA	water	Dunkel 2014	—
67.5 ppb	water_odor	Leffingwell	—

In a food matrix

0.340 ppb – 228 ppb

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

Threshold	Matrix	Source	Paper
0.140 ppb	water (food: lime)	Literature corpus	15826061, 30972045
Flagged: 143× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.340 ppb	water (food: truffle)	Literature corpus	36737983
1.6 ppb	water (food: rice)	Literature corpus	26973621, 28784469, 41675126
6.7 ppb SIDA	water (food: unknown)	Literature corpus	18570373, 19753606, 24053239 +9
8.5 ppb	water (food: bread)	Literature corpus	28958525
15.0 ppb	water (food: garlic)	Literature corpus	35558794
25.0 ppb SIDA	water (food: orange juice (reconstituted from concentrate))	Literature corpus	18570373, 15826061, 19753606 +19
25.0 ppb SIDA	water (food: hand-squeezed grapefruit juice)	Literature corpus	18570373, 15826061, 19753606 +19
25.0 ppb SIDA	water (food: pink guava)	Literature corpus	18570373, 15826061, 19753606 +19
25.0 ppb SIDA	water (food: reference standard (water))	Literature corpus	18570373, 15826061, 19753606 +19
71.5 ppb	water (food: wine)	Literature corpus	35011467
228 ppb	water (food: tea)	Literature corpus	31861730

Retronasal / in-mouth

0.600 ppb – 7.1 ppb

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

Threshold	Matrix	Source	Paper
0.600 ppb SIDA	water_retronasal	Rychlik 1998 · 1 studies	—
7.1 ppb SIDA	oil_retronasal	Rychlik 1998 · 1 studies	—

In air

1.5 ppb

Airborne detection — not comparable to a water threshold.

Threshold	Matrix	Source	Paper
1.5 ppb	air	Nagata 2003	—
1.5 ppb SIDA	air (food: reference standard (air))	Literature corpus	18570373, 15826061, 19753606 +19

Other matrix

0.220 ppb – 0.240 ppb

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

Threshold	Matrix	Source	Paper
0.220 ppb SIDA	oil_orthonasal	Rychlik 1998 · 1 studies	—
0.240 ppb SIDA	oil (oil) (food: hungarian-type salami)	Literature corpus	18570373, 15826061, 19753606 +19
62.0 ppb SIDA	cellulose	Rychlik 1998 · 1 studies	—
Flagged: 258× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.

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 (25.0 ppb, the engine's canonical value — see the 22 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
beer	30180.0	1207 ⚡	Corpus paper
wine	6590.0	264 ⚡	Corpus paper
tea	226.1	9.04	Corpus paper
lime	39.4	1.58	Corpus paper
bread	39.5	1.58	Corpus paper
garlic	19.9	0.79	Corpus paper
rice	0.7	0.03	—

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 acetaldehyde. 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 acetaldehyde in it. Full concentrations are in the OAV table above.

beer

measured · OAV 1207.2

457 cmpds

565 cmpds

617 cmpds

210 cmpds