ethyl isobutyrate

fruity ester Key food odorant

Found in 61 ingredients across the CompKitchen flavor graph.

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

2D Lewis Structure

Formula: C6H12O2
Molecular weight: 116.16 g/mol
PubChem CID: 7342 — full record on PubChem

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. Characteristic odor: fruity.

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

Properties

Odor description: fruity, ethereal, sweet, rummy, rubber
Odor threshold — orthonasal, in clean water: 0.060 ppb – 4.5 ppb median 0.100 ppb · 3 published values · see all 15 with sources
Volatility: high
CAS number: 97-62-1
Retention index: 972

Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

? Partial match

FEMA number: 4278
GRAS publication: GRAS 23
FEMA primary name: 2-(4-Methyl-5-thiazolyl)ethyl isobutyrate

Reported use levels (ppm by food category)

Typical vs maximum reported addition levels in finished food. Use as a regulatory ceiling reference — verify against the current GRAS publication for your product category.

Food category	Typical (ppm)	Maximum (ppm)
baked goods	5	30
cheese	0.1	0.16
gelatins/ puddings	10	42
soft candy	0.1	0.15

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

ethyl 2-methyl propanoate ethyl 2-methylpropanoate ethyl 2-methylpropanoate* ethyl-2-methyl propanoate

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.

sweet, rubber Flavornet Cas, Flavornet Name, Flavordb Odor Column 3 sources agree

—

fatty FlavorDB 2.0, Flavordb Odor Column 2 sources agree

chemical FlavorDB 2.0, Flavordb Odor Column 2 sources agree

alcoholic, ethereal, fruity, fusel, rubber, rummy, strawberry, sweet FlavorDB 2.0

Fruity, pungent: rum FlavorDB 2.0

apple, pine, chemical, fatty FlavorDB 2.0

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

15 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

0.060 ppb – 4.5 ppb

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

Threshold	Matrix	Source	Paper
0.060 ppb SIDA	water	Rychlik 1998 · 2 studies	—
0.100 ppb	water_odor	Leffingwell	—
4.5 ppb	water/ethanol 6:4 (food: american bourbon whisky)	Literature corpus	32619948, 32630090, 33995294 +5

In a food matrix

91.0 ppb – 186 ppb

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

Threshold	Matrix	Source	Paper
0.020 ppb	water (food: hand-squeezed grapefruit juice)	Literature corpus	32619948, 32630090, 33995294 +5
Flagged: 2278× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.089 ppb	water (food: reference standard (water))	Literature corpus	32619948, 32630090, 33995294 +5
Flagged: 512× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.100 ppb	water (food: japanese soy sauce)	Literature corpus	32619948, 32630090, 33995294 +5
Flagged: 455× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
91.0 ppb	water (food: rice)	Literature corpus	38846797, 40467248, 41675126
99.9 ppb	water (food: wine)	Literature corpus	32619948, 32630090, 39974541
186 ppb	water (food: unknown)	Literature corpus	33995294, 35396186

Retronasal / in-mouth

0.030 ppb – 0.750 ppb

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

Threshold	Matrix	Source	Paper
0.030 ppb SIDA	water_retronasal	Rychlik 1998 · 1 studies	—
0.750 ppb SIDA	oil_retronasal	Rychlik 1998 · 1 studies	—

In air

0.022 ppb

Airborne detection — not comparable to a water threshold.

Threshold	Matrix	Source	Paper
0.022 ppb	air	Nagata 2003	—

Other matrix

1.2 ppb – 14.0 ppb

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

Threshold	Matrix	Source	Paper
1.2 ppb SIDA	oil_orthonasal	Rychlik 1998 · 1 studies	—
1.2 ppb	oil (sunflower oil) (food: cocoa beans)	Literature corpus	32619948, 32630090, 33995294 +5
14.0 ppb	wine matrix (12% ethanol) (food: red wine)	Literature corpus	32619948, 32630090, 33995294 +5

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 (0.1 ppb, the engine's canonical value — see the 15 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
wine	72.2	722 ⚡	Corpus paper
rice	15.0	150 ⚡	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 ethyl isobutyrate. 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 ethyl isobutyrate in it. Full concentrations are in the OAV table above.

wine

measured · OAV 722.0

565 cmpds

spineless monkey orange

18 cmpds

26 cmpds

101 cmpds