3-methylbutanal
green aldehydeFound in 502 ingredients across the CompKitchen flavor graph.
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- Formula
- C5H10O
- Molecular weight
- 86.13 g/mol
- PubChem CID
- 11552 — full record on PubChem
Properties
- Odor description
- malty, chocolate, dark chocolate
- Odor threshold — orthonasal, in clean water
- 0.375 ppb – 2.8 ppb median 1.1 ppb · 3 published values · see all 27 with sources
- Volatility
- high
- CAS number
- 590-86-3
- Retention index
- 692
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
27 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
0.375 ppb – 2.8 ppbThe reference measurement — smelled in water. OAV is computed against this.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 0.375 ppb SIDA | water | Rychlik 1998 · 4 studies | — |
| 1.1 ppb | water_odor | Leffingwell | — |
| 2.8 ppb | water/ethanol 6:4 (food: american bourbon whisky) | Literature corpus | 33488534, 35369098, 35396186 +2 |
In a food matrix
0.200 ppb – 34.1 ppbMeasured in a real food, where the matrix shifts detection — not a clean-water value.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 0.200 ppb | water (food: wheat porridge / bread crumb) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 0.200 ppb | water (food: extruded wheat flour) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 0.500 ppb | water (food: green tea infusion (jingshan cha)) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 0.500 ppb | water (food: reference standard (water)) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 0.500 ppb | water (food: longjing green tea infusion) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 0.545 ppb | water (food: coffee) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 1.2 ppb | water (food: japanese soy sauce) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 3.4 ppb | water (food: onion) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 34.1 ppb | water (food: fish) | Literature corpus | 36950329 |
| 58.0 ppb | water (food: lamb) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| Flagged: 106× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden. | |||
| 156 ppb | water (food: unknown) | Literature corpus | 33488534, 35369098, 35396186 +1 |
| Flagged: 286× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden. | |||
Retronasal / in-mouth
0.145 ppb – 170 ppbTasted rather than smelled — a different sense, not comparable.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 0.145 ppb SIDA | water_retronasal | Rychlik 1998 · 2 studies | — |
| 10.8 ppb SIDA | oil_retronasal | Rychlik 1998 · 1 studies | — |
| 170 ppb | water_flavor | Leffingwell | — |
In air
0.100 ppbAirborne detection — not comparable to a water threshold.
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 0.100 ppb | air | Nagata 2003 | — |
Other matrix
2.8 ppb – 32.0 ppbMeasured in a non-aqueous medium (oil, starch, cellulose).
| Threshold | Matrix | Source | Paper |
|---|---|---|---|
| 2.8 ppb | ethanol/water (food: rum) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 2.8 ppb | ethanol/water 40/60 (food: rum (aged)) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 2.8 ppb | ethanol/water 40/60 (food: rum (young)) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 5.4 ppb | oil (sunflower oil) (food: gouda cheese) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 9.2 ppb SIDA | oil_orthonasal | Rychlik 1998 · 2 studies | — |
| 13.0 ppb | oil (sunflower oil) (food: cocoa beans) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 13.0 ppb | oil (sunflower oil) (food: cocoa powder) | Literature corpus | 33488534, 35369098, 35396186 +2 |
| 29.0 ppb SIDA | cellulose | Rychlik 1998 · 1 studies | — |
| 32.0 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 (0.5455 ppb, the engine's canonical value — see the 27 published values). OAV ≥ 1 = perceptible.
| Food | Concentration (ppb) | OAV | Source |
|---|---|---|---|
| cocoa | 171000.0 | 313474 ⚡ | Corpus paper |
| barley | 100000.0 | 183318 ⚡ | — |
| sourdough | 15490.0 | 28396 ⚡ | DOI |
| crab | 10000.0 | 18332 ⚡ | DOI |
| extra virgin olive oil | 8000.0 | 14665 ⚡ | Corpus paper |
| soybean | 6000.0 | 10999 ⚡ | PMID 37965015 |
| milk | 4000.0 | 7333 ⚡ | PMID 30687239 |
| olive | 100.0 | 183 ⚡ | DOI |
| beans | 77.3 | 142 ⚡ | DOI |
| coffee | 62.0 | 114 ⚡ | Corpus paper |
| garlic | 0.1 | 0.26 | PMID 37301918 |
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 3-methylbutanal. 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-methylbutanal in it. Full concentrations are in the OAV table above.
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