Skip to main content
vegetable sulfury & pungent green & herbal Vegan Gluten-free Dairy-free Nut-free Kosher Halal

Onion

Onion is a vegetable with 368 known flavor compounds. The most distinctive molecule is 3-mercapto-2-methylpentan-1-ol. It pairs most strongly with garlic, sharing 251 flavor compounds. Onion appears in 112,713 recipes, most commonly in indian cuisine.

Scientific name: Allium cepa
species of plant
Wikidata Q23485 (CC0)
Onion — ingredient reference image
368
Flavor Compounds
8
Top Pairings of 856 scored

Flavor Science

Flavor Profile Breakdown

368 compounds

How Onion's 368 known compounds break down by aroma category. Percentages are of compounds with a known label.

sour 49 · 13.3%
other 44 · 12.0%
sulfurous 43 · 11.7%
fruity 29 · 7.9%
floral 27 · 7.3%
savory 26 · 7.1%
green 26 · 7.1%
roasted 19 · 5.2%
caramel 17 · 4.6%
spicy 15 · 4.1%

Most Used In

Indian (1,056) Creole (728) World (633) British (373) European (336)

Flavor Compounds

135 of 368 are distinctive to onion — they appear in under 10% of foods. The remainder are the background most foods share.

Ordered by measured impact in onion — concentration against odour threshold where both are published, then by how distinctive the molecule is across the graph. Molecules measured here but not established as odorants sit below those that are.

Molecules volatile enough to reach the nose.
dimethyl trisulfide methyl propyl disulfide palmitic acid dimethyl disulfide methyl propyl trisulfide dipropyl trisulfide dipropyl disulfide 1-propanethiol dimethyl tetrasulfide succinic acid l-malic acid formic acid acetoin ethyl acetate acetic acid propionic acid 3-mercapto-2-methylpentan-1-ol propanethial s-oxide thiopropanal-s-oxide propanethiol allyl methyl trisulfide 3(2h)-furanone, 2-hexyl-5-methyl allyl methyl sulfide 2-isopropyl-3-methoxypyrazine 2,4-dimethyl-thiophene ethanethiol n-hexanal mesifurane diallyl trisulfide sulfur dioxide +172 more l-tyrosine citric acid nonadecanoic acid stearic acid tangeretin arachidic acid resveratrol rutin isoquercitrin dl-phenylalanine lutein isorhamnetin isoliquiritigenin taxifolin daidzein squalene genistein quercetin luteolin myricetin phloretin zeaxanthin aconitic acid stigmasterol naringenin inosine guanosine apigenin adenosine l-isoleucine l-proline l-alanine d-glucose 1-allylsulfanyl-1-propanethiol 1-methylsulfanyl-1-propanethiol 1-propylsulfanyl-1-propanethiol 3-(acetylthio)-2-methylfuran acetyloxy-dimethylfuranone allyl propyl disulphide bis(2-methyl-furyl) disulfide bis-(1-sulfanylpropyl)-sulfide ethyl furanone gamma-glutamyl-s-propenyl-l-cysteine sulfoxide methyl thiosulfinate propenyl propyl thiosulfinate propenyl propyl trisulfide thiosulphinates trans-(+)-s-propenyl-l-cysteine sulfoxide whiskey lactone isomer zwiebelanes methyl propenyl disulfide furanones 2-acetyl-5-methylfuran 2-methyltetrahydrofuran-3-one tartaric acid caffeine α-tocopherol retinol propenyl propyl disulfide dl-methionine

Most Abundant Molecules

21 of 368 quantified

Ranked by median concentration across published studies. Only 21 of Onion's 368 compounds have a measured concentration in the literature — the rest are confirmed present but not yet quantified. Bars are log-scaled.

1 palmitic acid 2.3 mg/kg
2 dipropyl trisulfide 1.3 mg/kg
3 dimethyl tetrasulfide 1.2 mg/kg
4 methyl propyl trisulfide 1.2 mg/kg
5 dipropyl disulfide 1.1 mg/kg
6 dimethyl trisulfide 952 µg/kg
7 methyl propyl disulfide 904 µg/kg
8 l-tyrosine 884 µg/kg
9 dimethyl disulfide 736 µg/kg
10 l-proline 300 µg/kg
11 formic acid 200 µg/kg
12 1-propanethiol 76 µg/kg
13 l-alanine 60 µg/kg
14 l-malic acid 50 µg/kg
15 citric acid 45 µg/kg

Best Pairings for Onion

Ranked by how often cooks actually use them together, across 453,403 recipes — the familiar answer first. Each pairing still carries its molecular score and shared-compound count; only the ORDER differs. Counts cover every characterised molecule the two ingredients have in common, not only the aroma-active ones, so they can exceed an ingredient’s aroma-compound count. For the chemistry-first view — where the surprising pairings live — see the molecular network below, the side-by-side comparison, or the Pairing Tool.

Molecular Neighborhood

Onion and its 10 closest compound-sharing relatives. Spoke thickness = shared compounds; circle size = that ingredient's own compound count. Drag to rearrange, scroll to zoom, click to open.

Molecular neighborhood diagram of onion — top 10 ingredients ranked by shared volatile compounds
1
Garlic herb
251 shared compounds
80%
2
Carrot vegetable root
239 shared compounds
64%
3
Olive plant
227 shared compounds
60%
4
Tomato vegetable fruit
253 shared compounds
60%
5
Parsley spice
228 shared compounds
59%
6
Celery spice
231 shared compounds
62%
7
Capsicum vegetable fruit
243 shared compounds
59%
8
Chicken meat
140 shared compounds
59%

Compare Onion side-by-side

Onion vs Garlic Onion vs Carrot Onion vs Olive Onion vs Tomato Onion vs Parsley Onion vs Celery

Recipes with Onion

View all →
Kalbi

Kalbi

onion
1 ingr. View →
Piyaz

Piyaz

onion
1 ingr. View →
Kattama

Kattama

onion
1 ingr. View →
Leeks Vinaigrette

Leeks Vinaigrette

onion
1 ingr. · 1 steps View →
Potato Salad

Potato Salad

onion
1 ingr. · 3 steps View →
Roast Beef

Roast Beef

onion
1 ingr. · 1 steps View →
Research basis

Onion is supported by 1,719 peer-reviewed papers

Drawn from PubMed + Europe PMC + food-science journals. Click any title to read the full abstract on the original source.
Show all 1,719 papers →