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3,4-dihydroxybenzoic acid

sour acid

Found in 389 ingredients across the CompKitchen flavor graph.

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

2D Lewis structure of 3,4-dihydroxybenzoic acid
2D Lewis Structure
Formula
C7H6O4
Molecular weight
154.12 g/mol
PubChem CID
72 — full record on PubChem

Properties

Odor description
balsamic, mild, phenolic
Odor threshold — in a food matrix
0.120 ppb – 107 ppb median 2.3 ppb · 3 published values · see all 3 with sources
Volatility
medium
CAS number
99-50-3
Retention index
4
Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

✓ Exact match
FEMA number
4430
GRAS publication
GRAS 24
FEMA primary name
3,4-Dihydroxybenzoic acid

Reported use levels (ppm by food category)

Typical vs maximum reported addition levels in finished food. Use as a regulatory ceiling reference — verify against the current GRAS publication for your product category.

Food category Typical (ppm) Maximum (ppm)
beverages (nonalcoholic) 300 500
chewing gum 500 2000
confectionery frostings 300 500
soft candy 300 500
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.

Also filed as
protocatechuic acid

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.

mild phenolic balsamic FlavorDB 2.0, Flavordb Odor Column 2 sources agree
3
balsamic, mild, phenolic shown above FlavorDB 2.0
386

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

0.120 ppb – 107 ppb

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

Threshold Matrix Source Paper
0.120 ppb water (food: beer) Literature corpus —
2.3 ppb water (food: tea) Literature corpus —
107 ppb water (food: unknown) Literature corpus —

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

Food Concentration (ppb) OAV Source
beer 14.0 6.10 —
tea 7.2 3.12 —

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 3,4-dihydroxybenzoic 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 3,4-dihydroxybenzoic acid in it. Full concentrations are in the OAV table above.

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