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octanoic acid

sour acid Key food odorant

Found in 571 ingredients across the CompKitchen flavor graph.

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

2D Lewis structure of octanoic acid
2D Lewis Structure
Formula
C8H16O2
Molecular weight
144.21 g/mol
PubChem CID
379 — full record on PubChem

Key food odorant (individualist)

Dunkel et al. 2014

Identified in the meta-analysis of 227 food samples as one of 151 individualist odorants — appears in <5% of foods, carries the diagnostic signature of specific ingredients. Characteristic odor: fatty, waxy.

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

Properties

Odor description
sweaty, cheesy, waxy
Odor threshold — orthonasal, in clean water
3000 ppb 2 published values · see all 24 with sources
Volatility
high
CAS number
124-07-2
Retention index
1190
Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

✓ Exact match
FEMA number
2799
GRAS publication
GRAS 3
FEMA primary name
OCTANOIC 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
caprylic 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.

sweaty, cheesy, waxy shown above Flavornet Cas, Flavornet Name, Flavordb Odor Column 3 sources agree
—
menthol FlavorDB 2.0, Flavordb Odor Column 2 sources agree
2
potato, sweaty, rancid, vinegar, cooked FlavorDB 2.0, Flavordb Odor Column 2 sources agree
1
fatty FlavorDB 2.0, Flavordb Odor Column 2 sources agree
1
sweaty, rancid, fatty FlavorDB 2.0, Flavordb Odor Column 2 sources agree
1
rancid soapy cheesy fatty brandy FlavorDB 2.0
487

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

24 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 —
3000 ppb SIDA water Rychlik 1998 · 1 studies —

In a food matrix

4.9 ppb – 3000 ppb

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

Threshold Matrix Source Paper
0.013 ppb water (food: beer) Literature corpus 17499755, 33889833
Flagged: 7649× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.300 ppb water (food: apple) Literature corpus 11302210
Flagged: 342× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.380 ppb SIDA water (food: strawberry) Literature corpus 32625638, 10552650, 11272845 +46
Flagged: 270× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
4.9 ppb water (food: tea) Literature corpus 29086878, 37188725, 41551788
6.6 ppb SIDA water (food: unknown) Literature corpus 32625638, 11272845, 19753606 +18
9.8 ppb water (food: milk) Literature corpus 10552650, 39479676
16.4 ppb water (food: pork) Literature corpus 39085314
22.3 ppb water (food: baijiu) Literature corpus 35513386
55.0 ppb water (food: wine) Literature corpus 25939071, 32657431, 35011467 +1
73.0 ppb SIDA water (food: garlic) Literature corpus 32625638, 10552650, 11272845 +46
132 ppb SIDA water (food: chocolate) Literature corpus 32625638, 17898464
190 ppb SIDA water (food: goat milk) Literature corpus 32625638, 10552650, 11272845 +46
595 ppb water (food: lime) Literature corpus 15826061, 24789719, 30972045
1089 ppb SIDA water (food: peanut) Literature corpus 32625638, 10552650, 11272845 +46
1176 ppb water (food: ginger) Literature corpus 37936928
1182 ppb water (food: bread) Literature corpus 41613919
1622 ppb water (food: beef) Literature corpus 37701748, 38974721
1666 ppb water (food: rice) Literature corpus 26973621, 29877224, 38846797 +1
2083 ppb water (food: olive oil) Literature corpus 28671107
3000 ppb SIDA water (food: reference standard (water)) Literature corpus 32625638, 10552650, 11272845 +46

Retronasal / in-mouth

5300 ppb

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

Threshold Matrix Source Paper
5300 ppb water_flavor Leffingwell —
5300 ppb SIDA water_retronasal Rychlik 1998 · 1 studies —

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 (161.0 ppb, the engine's canonical value — see the 24 published values). OAV ≥ 1 = perceptible.

Food Concentration (ppb) OAV Source
grape 62000.0 385 ⚡ PMID 34623142
cheese 25033.5 155 ⚡ Corpus paper
milk 4535.5 28.2 ⚡ Corpus paper
white wine 2660.0 16.5 ⚡ DOI
bread 1180.0 7.33 Corpus paper
baijiu 1173.0 7.29 Corpus paper
pork 718.6 4.46 PMID 41315583
rice 615.1 3.82 Corpus paper
blueberry 580.0 3.60 DOI
beer 496.4 3.08 Corpus paper
wine 160.0 0.99 PMID 27405438
garlic 147.0 0.91 Corpus paper
red wine 100.0 0.62 Corpus paper
beef 47.0 0.29 Corpus paper
ginger 25.2 0.16 —
lime 15.0 0.09 —
tea 4.4 0.03 —
olive oil 3.1 0.02 —
chocolate 2.3 0.01 —
apple 0.4 0.00 —

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

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