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n-hexanal

green aldehyde Key food odorant

Found in 8 ingredients across the CompKitchen flavor graph.

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

Key food odorant (generalist)

Dunkel et al. 2014

Identified 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: green, grassy.

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

Properties

Odor description
green, grassy, fatty, tallowy, apple
Odor threshold — orthonasal, in clean water
4.8 ppb – 10.5 ppb median 7.6 ppb · 2 published values · see all 48 with sources
CAS number
66-25-1
Not in FEMA GRAS publications 1-33. Of 3,367 listed flavoring substances, none match this compound name. May still be food-safe under other regulatory routes (FDA 21 CFR 172, EFSA, JECFA) — check femaflavor.org for the authoritative current list.

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.

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 FlavorDB 2.0
1
waxy aldehydes FlavorDB 2.0
1
waxy aldehyde FlavorDB 2.0
1
green, grassy, fatty, tallowy, apple shown above Llm Adjudicated
—

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

48 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

4.8 ppb – 10.5 ppb

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

Threshold Matrix Source Paper
4.8 ppb water_odor Leffingwell —
10.5 ppb SIDA water Rychlik 1998 · 5 studies —

In a food matrix

0.500 ppb – 940 ppb

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

Threshold Matrix Source Paper
0.007 ppb water (food: beer) Literature corpus —
Flagged: 1515× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.030 ppb water (food: melon) Literature corpus —
Flagged: 333× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.500 ppb water (food: lime) Literature corpus —
0.730 ppb water (food: longjing green tea infusion) Literature corpus —
2.0 ppb water (food: pork) Literature corpus —
2.4 ppb water (food: green tea infusion (jingshan cha)) Literature corpus —
2.4 ppb water (food: pink guava) Literature corpus —
2.4 ppb water (food: reference standard (water)) Literature corpus —
2.4 ppb water (food: goat milk) Literature corpus —
2.8 ppb water (food: pepper) Literature corpus —
2.9 ppb water (food: chocolate) Literature corpus —
3.5 ppb water (food: onion) Literature corpus —
4.5 ppb water (food: reference standard (water)) Literature corpus —
4.5 ppb water (food: wheat porridge / bread crumb) Literature corpus —
4.5 ppb water (food: extruded wheat flour) Literature corpus —
6.7 ppb water (food: strawberry) Literature corpus —
9.7 ppb water (food: truffle) Literature corpus —
10.0 ppb water (food: beef vegetable gravy) Literature corpus —
10.0 ppb water (food: pork vegetable gravy) Literature corpus —
10.5 ppb water (food: orange juice (reconstituted from concentrate)) Literature corpus —
10.5 ppb water (food: hand-squeezed grapefruit juice) Literature corpus —
13.5 ppb water (food: fish) Literature corpus —
24.3 ppb water (food: apple) Literature corpus —
30.0 ppb water (food: milk) Literature corpus —
32.0 ppb water (food: tea) Literature corpus —
38.2 ppb water (food: unknown) Literature corpus —
52.0 ppb water (food: soy sauce) Literature corpus —
56.0 ppb water (food: lamb) Literature corpus —
73.0 ppb water (food: smoked cooked loin (pork)) Literature corpus —
101 ppb water (food: wine) Literature corpus —
278 ppb water (food: peanut) Literature corpus —
307 ppb water (food: rum) Literature corpus —
549 ppb water (food: rice) Literature corpus —
554 ppb water (food: beef) Literature corpus —
940 ppb water (food: bread) Literature corpus —
1074 ppb water (food: olive oil) Literature corpus —
Flagged: 107× 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

16.0 ppb – 132 ppb

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

Threshold Matrix Source Paper
16.0 ppb SIDA water_retronasal Rychlik 1998 · 1 studies —
46.0 ppb water_flavor Leffingwell —
132 ppb SIDA oil_retronasal Rychlik 1998 · 2 studies —

In air

0.280 ppb – 0.331 ppb

Airborne detection — not comparable to a water threshold.

Threshold Matrix Source Paper
0.280 ppb air Nagata 2003 —
0.331 ppb air (C2_cometto_muniz_abraham) Cometto-Muñiz (PMC) —

Other matrix

30.0 ppb – 5870 ppb

Measured in a non-aqueous medium (oil, starch, cellulose).

Threshold Matrix Source Paper
30.0 ppb SIDA starch Rychlik 1998 · 1 studies —
87.9 ppb ethanol/water 40/60 (food: rum (aged)) Literature corpus —
88.0 ppb ethanol/water (food: rum) Literature corpus —
210 ppb SIDA oil_orthonasal Rychlik 1998 · 2 studies —
5870 ppb SIDA meat_water 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.

Found in

Measured impact first, then profile share

Every ingredient known to contain n-hexanal. 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 n-hexanal in it.

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