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nonanoic acid

sour acid

Found in 353 ingredients across the CompKitchen flavor graph.

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

2D Lewis structure of nonanoic acid
2D Lewis Structure
Formula
C9H18O2
Molecular weight
158.24 g/mol
PubChem CID
8158 — full record on PubChem

Properties

Odor description
waxy, cheesy, fatty, green, dairy
Odor threshold — orthonasal, in clean water
3000 ppb 1 published value · see all 14 with sources
Volatility
medium
CAS number
112-05-0
Retention index
1282
Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

✓ Exact match
FEMA number
2784
GRAS publication
GRAS 3
FEMA primary name
NONANOIC ACID

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

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
pelargonic 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.

green, fat Flavornet Cas, Flavornet Name, Flavordb Odor Column 3 sources agree
—
green FlavorDB 2.0, Flavordb Odor Column 2 sources agree
2
pine FlavorDB 2.0, Flavordb Odor Column 2 sources agree
1
fatty FlavorDB 2.0, Flavordb Odor Column 2 sources agree
1
Fatty, waxy and cheesy with a mild sweet creamy background FlavorDB 2.0
238
cheese, cultured dairy, dirty, fat, green, waxy FlavorDB 2.0
119

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

14 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

3000 ppb

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

Threshold Matrix Source Paper
3000 ppb water_odor Leffingwell —

In a food matrix

0.600 ppb – 2202 ppb

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

Threshold Matrix Source Paper
0.032 ppb water (food: tea) Literature corpus 38690105, 41551788
Flagged: 747× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.600 ppb water (food: apple) Literature corpus 11302210
10.0 ppb SIDA water (food: unknown) Literature corpus 32625638, 20858266, 28446195 +12
15.0 ppb SIDA water (food: chocolate) Literature corpus 32625638, 11302210, 17411067 +25
17.5 ppb water (food: pork) Literature corpus 39085314
19.7 ppb water (food: grape) Literature corpus 36890905
23.5 ppb water (food: baijiu) Literature corpus 35513386
32.8 ppb water (food: rum) Literature corpus 17411067
60.0 ppb SIDA water (food: honey) Literature corpus 32625638, 11302210, 17411067 +25
1064 ppb water (food: bread) Literature corpus 38519512
1257 ppb water (food: tomato) Literature corpus 39227423
1275 ppb water (food: beef) Literature corpus 29037691, 37701748, 38974721
2202 ppb water (food: olive oil) Literature corpus 28671107

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 (28.146 ppb, the engine's canonical value — see the 14 published values). OAV ≥ 1 = perceptible.

Food Concentration (ppb) OAV Source
grape 275000.0 9770 ⚡ PMID 34623142
cocoa 38000.0 1350 ⚡ —
millet 3180.0 113 ⚡ PMID 41281326
baijiu 1272.0 45.2 ⚡ Corpus paper
tomato 1260.0 44.8 ⚡ Corpus paper
bread 1073.0 38.1 ⚡ Corpus paper
beef 73.0 2.59 Corpus paper
capsicum 49.7 1.77 —
olive oil 3.4 0.12 —
rice 1.7 0.06 —
rum 1.4 0.05 —
chocolate 1.4 0.05 —
tea 0.6 0.02 —
apple 0.4 0.01 —

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

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