butanoic acid
dairy acid Key food odorantFound in 97 ingredients across the CompKitchen flavor graph.
Look up another compound — search by name, CAS number, PubChem CID, or FEMA #.
- Formula
- C4H8O2
- Molecular weight
- 88.11 g/mol
- PubChem CID
- 264 — full record on PubChem
Key food odorant (generalist)
Dunkel et al. 2014Identified in the meta-analysis of 227 food samples as one of 16 generalist odorants — appears in >25% of foods, typically from generic Maillard, lipid-oxidation, or fermentation pathways. Characteristic odor: sweaty, cheesy.
Properties
- Odor description
- rancid, cheesy, sweaty, butter, sour
- Odor threshold — orthonasal, in clean water
- 240 ppb – 620 ppb median 430 ppb · 2 published values · see all 32 with sources
- Volatility
- high
- CAS number
- 107-92-6
- Retention index
- 861
FEMA GRAS — Generally Recognized As Safe for flavoring use
- FEMA number
- 3991
- GRAS publication
- GRAS 20
- FEMA primary name
- Butanoic acid, 2-heptyl ester
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
32 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
240 ppb – 620 ppbThe reference measurement — smelled in water. OAV is computed against this.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 240 ppb | water_odor | Leffingwell | — |
| 620 ppb SIDA | water | Rychlik 1998 · 4 studies | — |
In a food matrix
3.0 ppb – 7700 ppbMeasured in a real food, where the matrix shifts detection — not a clean-water value.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 2.0 ppb SIDA | water (food: wheat) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| Flagged: 102× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden. | |||
| 3.0 ppb | water (food: rice) | Literature corpus | 38846797, 40467248 |
| 16.2 ppb | water (food: baijiu) | Literature corpus | 35513386 |
| 27.0 ppb SIDA | water (food: garlic) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 51.1 ppb SIDA | water (food: rum) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 59.0 ppb SIDA | water (food: milk) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 59.8 ppb | water (food: tea) | Literature corpus | 39335804 |
| 60.0 ppb SIDA | water (food: lamb) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 166 ppb | water (food: unknown) | Literature corpus | 11272845, 19753606, 28602301 +6 |
| 240 ppb SIDA | water (food: reference standard (water)) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 250 ppb SIDA | water (food: peanut) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 812 ppb SIDA | water (food: lime) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 1611 ppb SIDA | water (food: wine) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 1616 ppb SIDA | water (food: olive oil) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 1622 ppb SIDA | water (food: bread) | Literature corpus | 30779560, 28274420, 28490062 +1 |
| 2400 ppb SIDA | water (food: reference standard (water)) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 7700 ppb SIDA | water (food: beef vegetable gravy) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 7700 ppb SIDA | water (food: pork vegetable gravy) | Literature corpus | 30779560, 11272845, 19753606 +15 |
Retronasal / in-mouth
6200 ppbTasted rather than smelled — a different sense, not comparable.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 6200 ppb SIDA | water_retronasal | Rychlik 1998 · 3 studies | — |
| 6500 ppb | water_flavor | Leffingwell | — |
In air
0.190 ppbAirborne detection — not comparable to a water threshold.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 0.190 ppb | air | Nagata 2003 | — |
Other matrix
100 ppb – 1200 ppbMeasured in a non-aqueous medium (oil, starch, cellulose).
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 100 ppb SIDA | starch | Rychlik 1998 · 1 studies | — |
| 135 ppb SIDA | oil_orthonasal | Rychlik 1998 · 1 studies | — |
| 135 ppb SIDA | oil (sunflower oil) (food: gouda cheese) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 135 ppb SIDA | oil (sunflower oil) (food: cocoa beans) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 135 ppb SIDA | oil (sunflower oil) (food: cocoa powder) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 200 ppb SIDA | wine (food: red wine (cabernet sauvignon)) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 480 ppb SIDA | wine matrix (12% ethanol) (food: rum / red wine) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 1200 ppb SIDA | ethanol/water (food: rum / red wine) | Literature corpus | 30779560, 11272845, 19753606 +15 |
| 1200 ppb SIDA | ethanol/water 40/60 (food: rum (aged)) | Literature corpus | 30779560, 11272845, 19753606 +15 |
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 (240.0 ppb, the engine's canonical value — see the 32 published values). OAV ≥ 1 = perceptible.
| Food | Concentration (ppb) | OAV | Source |
|---|---|---|---|
| coffee | 200000.0 | 833 ⚡ | PMID 34421873 |
| white wine | 150000.0 | 625 ⚡ | DOI |
| cream | 71000.0 | 296 ⚡ | PMID 39045299 |
| carrot | 38715.0 | 161 ⚡ | — |
| cheese | 15000.0 | 62.5 ⚡ | Corpus paper |
| beef | 5000.0 | 20.8 ⚡ | Corpus paper |
| whey | 2550.0 | 10.6 ⚡ | — |
| wine | 1839.0 | 7.66 | Corpus paper |
| cucumber | 1400.0 | 5.83 | Corpus paper |
| lamb | 920.0 | 3.83 | Corpus paper |
| milk | 816.0 | 3.40 | Corpus paper |
| peanut | 795.1 | 3.31 | Corpus paper |
| baijiu | 775.0 | 3.23 | PMID 41190275 |
| beans | 63.7 | 0.27 | DOI |
| garlic | 60.0 | 0.25 | Corpus paper |
| goat milk | 50.0 | 0.21 | DOI |
| tea | 50.5 | 0.21 | Corpus paper |
| pear | 20.0 | 0.08 | Corpus paper |
| lime | 9.7 | 0.04 | Corpus paper |
| olive oil | 2.3 | 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 shareEvery ingredient known to contain butanoic 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 butanoic acid in it. Full concentrations are in the OAV table above.
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