hexanoic acid
sour acid Key food odorantFound in 667 ingredients across the CompKitchen flavor graph.
Look up another compound — search by name, CAS number, PubChem CID, or FEMA #.
- Formula
- C6H12O2
- Molecular weight
- 116.16 g/mol
- PubChem CID
- 8892 — full record on PubChem
Key food odorant (intermediary)
Dunkel et al. 2014Identified in the meta-analysis of 227 food samples as one of 57 intermediary odorants — appears in 5–25% of foods.
Properties
- Odor description
- sweaty, cheesy, fatty, sour
- Odor threshold — orthonasal, in clean water
- 3000 ppb – 4000 ppb median 3500 ppb · 2 published values · see all 25 with sources
- Volatility
- high
- CAS number
- 142-62-1
- Retention index
- 984
FEMA GRAS — Generally Recognized As Safe for flavoring use
- FEMA number
- 2559
- GRAS publication
- GRAS 3
- FEMA primary name
- HEXANOIC ACID
Use-level matrix not extracted for this substance — check the source publication for current ppm guidance.
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.
Same molecule, unified here — previously counted and displayed as separate compounds.
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.
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
25 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 – 4000 ppbThe reference measurement — smelled in water. OAV is computed against this.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 3000 ppb | water_odor | Leffingwell | — |
| 4000 ppb SIDA | water | Rychlik 1998 · 4 studies | — |
In a food matrix
1.6 ppb – 3000 ppbMeasured in a real food, where the matrix shifts detection — not a clean-water value.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 1.6 ppb | water (food: wine) | Literature corpus | 25939071, 32657431, 35011467 +2 |
| 2.0 ppb | water (food: rice) | Literature corpus | 29877224, 38846797, 40467248 |
| 3.1 ppb | water (food: tea) | Literature corpus | 31861730, 39877541, 41551788 |
| 12.0 ppb | water (food: fish) | Literature corpus | 24594176, 36144849, 37003052 |
| 19.5 ppb | water (food: baijiu) | Literature corpus | 35513386 |
| 43.5 ppb | water (food: milk) | Literature corpus | 10552650, 39479676 |
| 49.0 ppb SIDA | water (food: unknown) | Literature corpus | 32625638, 19753606, 25857434 +14 |
| 60.0 ppb | water (food: lamb) | Literature corpus | 22789457 |
| 110 ppb SIDA | water (food: chocolate) | Literature corpus | 32625638, 17898464 |
| 177 ppb | water (food: grape) | Literature corpus | 36890905 |
| 658 ppb SIDA | water (food: peanut) | Literature corpus | 30779560, 32625638, 10552650 +46 |
| 993 ppb | water (food: tomato) | Literature corpus | 39227423 |
| 996 ppb | water (food: beef) | Literature corpus | 29037691, 37701748, 38974721 |
| 1445 ppb SIDA | water (food: bread) | Literature corpus | 30779560, 28274420, 28490062 +2 |
| 1829 ppb SIDA | water (food: olive oil) | Literature corpus | 30779560, 28671107 |
| 3000 ppb SIDA | water (food: reference standard (water)) | Literature corpus | 30779560, 32625638, 10552650 +46 |
Retronasal / in-mouth
1500 ppb – 5400 ppbTasted rather than smelled — a different sense, not comparable.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 1500 ppb SIDA | water_retronasal | Rychlik 1998 · 1 studies | — |
| 5400 ppb | water_flavor | Leffingwell | — |
In air
0.600 ppbAirborne detection — not comparable to a water threshold.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 0.600 ppb | air | Nagata 2003 | — |
Other matrix
800 ppb – 11000 ppbMeasured in a non-aqueous medium (oil, starch, cellulose).
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 800 ppb SIDA | wine (food: red wine (cabernet sauvignon)) | Literature corpus | 30779560, 32625638, 10552650 +46 |
| 5400 ppb SIDA | oil_orthonasal | Rychlik 1998 · 1 studies | — |
| 5400 ppb SIDA | oil (sunflower oil) (food: gouda cheese) | Literature corpus | 30779560, 32625638, 10552650 +46 |
| 11000 ppb SIDA | starch | 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 (143.6 ppb, the engine's canonical value — see the 25 published values). OAV ≥ 1 = perceptible.
| Food | Concentration (ppb) | OAV | Source |
|---|---|---|---|
| wine | 63460.0 | 442 ⚡ | PMID 27405438 |
| cream | 39965.0 | 278 ⚡ | PMID 39045299 |
| cheese | 20000.0 | 139 ⚡ | Corpus paper |
| milk | 19080.0 | 133 ⚡ | Corpus paper |
| mace | 18200.0 | 127 ⚡ | PMID 41794470 |
| lamb | 9960.0 | 69.4 ⚡ | Corpus paper |
| white wine | 9810.0 | 68.3 ⚡ | DOI |
| gouda cheese | 3400.0 | 23.7 ⚡ | Corpus paper |
| turkey | 1675.0 | 11.7 ⚡ | PMID 15713037 |
| tomato | 996.0 | 6.94 | Corpus paper |
| yogurt | 305.1 | 2.12 | Corpus paper |
| red wine | 100.0 | 0.70 | — |
| beef | 60.0 | 0.42 | Corpus paper |
| chocolate | 22.7 | 0.16 | Corpus paper |
| fish | 23.0 | 0.16 | Corpus paper |
| bread | 14.7 | 0.10 | Corpus paper |
| tea | 6.4 | 0.04 | — |
| olive oil | 2.7 | 0.02 | — |
| rice | 1.0 | 0.01 | — |
| rum | 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 shareEvery ingredient known to contain hexanoic 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 hexanoic acid in it. Full concentrations are in the OAV table above.
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