furan

caramel furan

Found in 23 ingredients across the CompKitchen flavor graph.

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

2D Lewis Structure

Formula: C4H4O
Molecular weight: 68.07 g/mol
PubChem CID: 8029 — full record on PubChem

Properties

Odor description: ethereal, nutty, roasted
Odor threshold — in a food matrix: 0.276 ppb – 4.9 ppb median 4.9 ppb · 5 published values · see all 6 with sources
Volatility: high
CAS number: 110-00-9

Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

? Partial match

FEMA number: 4868
GRAS publication: GRAS 28
CAS number: 61315-75-1
FEMA primary name: 4-(4-Methyl-3-penten-1-yl)-2(5H)-furanone

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	0.0001	0.001
beverages, alcoholic	1e-05	0.0001
beverages, non-alcoholic	1e-05	0.0001
beverages, nonalcoholic	1e-05	0.0001
breakfast cereals	0.0001	0.001
cheeses	0.001	0.01
chewing gum	0.0001	0.001
confections and frostings	0.0001	0.001
egg products	0.0001	0.001
fats and oils	0.001	0.01
fish products	0.0001	0.001
frozen dairy	0.0001	0.001
fruit ices	1e-05	0.0001
gelatins and puddings	0.0001	0.001
gravies	0.001	0.01
hard candy	0.0001	0.001
imitation dairy	0.0001	0.001
instant coffee and tea	1e-05	0.0001
meat products	1e-05	0.0001
milk products	1e-05	0.0001
nut products	0.0001	0.001
other grains	0.0001	0.001
processed fruits	1e-05	0.0001
seasonings and flavors	0.01	0.1
snack foods	0.0001	0.001
soft candy	0.0001	0.001
soups	0.0001	0.001

Source: FEMA GRAS publications 1-33. 73 related FEMA records for this name — verify the exact substance for regulatory use.

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.

baking aroma FlavorDB 2.0

baking, roasting, nutty, caramel FlavorDB 2.0

ethereal, nutty, roasted 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

6 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.

In a food matrix

0.276 ppb – 4.9 ppb

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

Threshold	Matrix	Source	Paper
0.276 ppb	water (food: rice)	Literature corpus	28784469
4.2 ppb	water (food: unknown)	Literature corpus	17687706, 28491071, 30166567 +4
4.9 ppb	water (food: bread)	Literature corpus	28958525
494 ppb	water (food: melon)	Literature corpus	32093373
Flagged: 101× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
655 ppb	water (food: rum)	Literature corpus	17687706, 28491071, 28784469 +7
Flagged: 134× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.

In air

9900 ppb

Airborne detection — not comparable to a water threshold.

Threshold	Matrix	Source	Paper
9900 ppb	air	Nagata 2003	—

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 (249.45 ppb, the engine's canonical value — see the 6 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
melon	488.5	1.96	Corpus paper
bread	15.7	0.06	—
rum	10.3	0.04	—
rice	0.1	0.00	—

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 furan. 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 furan in it. Full concentrations are in the OAV table above.

254 cmpds

11 cmpds

21 cmpds

34 cmpds