caffeic acid

sour phenylpropanoid

Found in 387 ingredients across the CompKitchen flavor graph.

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

2D Lewis Structure

Formula: C9H8O4
Molecular weight: 180.16 g/mol
PubChem CID: 689043 — full record on PubChem

Properties

Odor threshold — in a food matrix: 1.0 ppb – 405 ppb median 4.3 ppb · 5 published values · see all 5 with sources
Volatility: medium
CAS number: 331-39-5
Retention index: 2

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.

Published thresholds

5 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

1.0 ppb – 405 ppb

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

Threshold	Matrix	Source	Paper
1.0 ppb	water (food: mushroom)	Literature corpus	32786833
4.0 ppb	water (food: unknown)	Literature corpus	19320050, 20730965, 23884120 +18
4.3 ppb	water (food: tea)	Literature corpus	34299388, 40226889, 41348501
171 ppb	water (food: tomato)	Literature corpus	38253713
405 ppb	water (food: beer)	Literature corpus	38698043, 41730959

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 (4.3 ppb, the engine's canonical value — see the 5 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
mentha piperita	11690.0	2719 ⚡	Corpus paper
beer	12.0	2.80	—
tomato	11.8	2.75	—
tea	10.6	2.46	—
mushroom	1.0	0.23	—

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 caffeic acid. 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 caffeic acid in it. Full concentrations are in the OAV table above.

457 cmpds

519 cmpds

617 cmpds

434 cmpds