methacrolein

green oxygenated compound

Found in 2 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: 6562 — full record on PubChem

Properties

Odor threshold — in a food matrix: 0.250 ppb – 1.7 ppb median 1.7 ppb · 3 published values · see all 4 with sources
Volatility: high
CAS number: 78-85-3

Not in FEMA GRAS publications 1-33. Of 3,367 listed flavoring substances, none match this compound name. May still be food-safe under other regulatory routes (FDA 21 CFR 172, EFSA, JECFA) — check femaflavor.org for the authoritative current list.

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

2-methyl-2-propenal

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

Published thresholds

4 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

0.250 ppb – 1.7 ppb

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

Threshold	Matrix	Source	Paper
0.250 ppb	water (food: rice)	Literature corpus	41675126
1.7 ppb	water (food: unknown)	Literature corpus	40761387
574 ppb	water (food: tea)	Literature corpus	31861730
Flagged: 346× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.

In air

8.5 ppb

Airborne detection — not comparable to a water threshold.

Threshold	Matrix	Source	Paper
8.5 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 (1.66 ppb, the engine's canonical value — see the 4 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
tea	570.0	343 ⚡	Corpus paper
rice	0.1	0.05	—

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

106 cmpds

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