isobutanal

green aldehyde Key food odorant

Found in 1 ingredient across the CompKitchen flavor graph.

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

Key food odorant (intermediary)

Dunkel et al. 2014

Identified in the meta-analysis of 227 food samples as one of 57 intermediary odorants — appears in 5–25% of foods.

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

Properties

Odor threshold — orthonasal, in clean water: 1.0 ppb – 5.9 ppb median 1.2 ppb · 3 published values · see all 12 with sources
CAS number: 78-84-2
Retention index: 629

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.

Published thresholds

12 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

1.0 ppb – 5.9 ppb

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

Threshold	Matrix	Source	Paper
1.0 ppb SIDA	water	Rychlik 1998 · 5 studies	—
1.2 ppb	water_odor	Leffingwell	—
5.9 ppb	water/ethanol 6:4 (food: american bourbon whisky)	Literature corpus	24594176, 33488534, 36144849 +1

In a food matrix

0.490 ppb – 1.0 ppb

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

Threshold	Matrix	Source	Paper
0.490 ppb	water (food: green tea infusion (jingshan cha))	Literature corpus	24594176, 33488534, 36144849 +1
0.490 ppb	water (food: reference standard (water))	Literature corpus	24594176, 33488534, 36144849 +1
0.490 ppb	water (food: longjing green tea infusion)	Literature corpus	24594176, 33488534, 36144849 +1
1.0 ppb	water (food: extruded wheat flour)	Literature corpus	24594176, 33488534, 36144849 +1

Retronasal / in-mouth

0.700 ppb – 3.4 ppb

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

Threshold	Matrix	Source	Paper
0.700 ppb SIDA	water_retronasal	Rychlik 1998 · 1 studies	—
3.4 ppb SIDA	oil_retronasal	Rychlik 1998 · 1 studies	—

Other matrix

18.0 ppb – 56.0 ppb

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

Threshold	Matrix	Source	Paper
18.0 ppb SIDA	cellulose	Rychlik 1998 · 1 studies	—
23.2 ppb SIDA	oil_orthonasal	Rychlik 1998 · 2 studies	—
56.0 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.

Thresholds in published tables

Numbers printed in open-access papers, grouped by the medium the table states. Median and full range of the values; “agree” means two or more papers whose middle 80% of values sit within 100×. Not reviewed.

Medium	Median	Range	Values	Papers	Papers agree?
air	0.49 µg/L air	0.0015–1.5e+03	7	6	no (5.9 decades)
ethanol solution	1300 ppb	5.9–1.3e+03	5	3	no (2.3 decades)
food matrix	2.45 ppb	0.35–8e+03	14	14	no (2.8 decades)
oil	236.5 ppb	43–430	2	2	yes
unstated	6 ppb	0.006–1.3e+06	39	33	no (3.4 decades)
water	1.5 ppb	0.49–1.31e+03	23	20	yes

Found in

Measured impact first, then profile share

Every ingredient known to contain isobutanal. 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 isobutanal in it.

chocolate

plant derivative

177 cmpds

Into the chemistry?

Get a molecule-level pairing breakdown each week — which ingredients share a compound, and why it matters at the table. Free, no spam.

Prefer an account? Create a free account to save pairings and unlock the full chemistry.

Try the pairing tools to see which ingredient combinations rely on isobutanal, or compare two ingredients side-by-side.