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trans-4,5-epoxy-(e)-2-decenal

nutty aldehyde

Found in 13 ingredients across the CompKitchen flavor graph.

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

Properties

Odor description
metallic, green, fatty
Odor threshold — orthonasal, in clean water
0.120 ppb 1 published value · see all 9 with sources
CAS number
154002-67-2
Retention index
2030
Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

✓ Exact match
FEMA number
4037
GRAS publication
GRAS 21
FEMA primary name
4,5-EPOXY-(E)-2-DECENAL

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
trans-4,5-epoxy-trans-2-decenal

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.

metallic FlavorDB 2.0
6
vegetal/green hazelnut nuance FlavorDB 2.0
1
metallic odor FlavorDB 2.0
1
metallic, green, fatty 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

9 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

0.120 ppb

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

Threshold Matrix Source Paper
0.120 ppb SIDA water Rychlik 1998 · 1 studies —

In a food matrix

0.130 ppb – 0.220 ppb

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

Threshold Matrix Source Paper
0.130 ppb water (food: reference standard (water)) Literature corpus 24594176, 36144849, 37003052
0.220 ppb water (food: pink guava) Literature corpus 24594176, 36144849, 37003052
33.0 ppb water (food: fish) Literature corpus 24594176, 36144849, 37003052
Flagged: 150× 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

0.015 ppb – 3.0 ppb

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

Threshold Matrix Source Paper
0.015 ppb SIDA water_retronasal Rychlik 1998 · 1 studies —
3.0 ppb SIDA oil_retronasal Rychlik 1998 · 1 studies —

Other matrix

0.190 ppb – 1.3 ppb

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

Threshold Matrix Source Paper
0.190 ppb SIDA starch Rychlik 1998 · 1 studies —
0.800 ppb SIDA buttermilk_orthonasal Rychlik 1998 · 1 studies —
1.3 ppb SIDA oil_orthonasal 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 (0.175 ppb, the engine's canonical value — see the 9 published values). OAV ≥ 1 = perceptible.

Food Concentration (ppb) OAV Source
fish 32.0 183 ⚡ Corpus paper

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 trans-4,5-epoxy-(e)-2-decenal. 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 trans-4,5-epoxy-(e)-2-decenal in it. Full concentrations are in the OAV table above.

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