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trans-2-pentenal

green aldehyde

Found in 30 ingredients across the CompKitchen flavor graph.

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

Properties

Odor description
green, apple, fruity, pungent
Odor threshold — orthonasal, in clean water
1500 ppb 1 published value · see all 7 with sources
CAS number
764-39-6
Retention index
754
Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

✓ Exact match
FEMA number
3218
GRAS publication
GRAS 4
FEMA primary name
2-PENTENAL

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
e-2-pentenal

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.

due to spoilage FlavorDB 2.0, Flavordb Odor Column 2 sources agree
1
apple, fruit, fruity, green, orange, pungent, strawberry, tomato FlavorDB 2.0
26
pleasant FlavorDB 2.0
1
green, apple, fruity, pungent 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

7 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

1500 ppb

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

Threshold Matrix Source Paper
1500 ppb water_odor Leffingwell —

In a food matrix

3.2 ppb – 1117 ppb

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

Threshold Matrix Source Paper
1.1 ppb water (food: tomato) Literature corpus —
Flagged: 121× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
3.2 ppb water (food: onion) Literature corpus —
30.0 ppb water (food: fish) Literature corpus —
226 ppb water (food: peanut) Literature corpus —
503 ppb water (food: unknown) Literature corpus —
1117 ppb water (food: olive oil) Literature corpus —

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 trans-2-pentenal. 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-2-pentenal in it.

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