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A close photo of an onion
NewVegetablesStem vegetables

Onion

The onion is an allium vegetable known for its layered bulb and pungent flavor. It is used raw or cooked in cuisines around the world, and provides fiber, vitamin C, and several minerals with relatively few calories.

Did you know ?

  • 1 Onions belong to the Allium genus, alongside garlic, leeks, chives, and shallots.
  • 2 The compounds released when an onion is cut can irritate the eyes and cause tears.
  • 3 Yellow, red, and white onions differ in flavor, color, and common culinary uses.

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Nutrition## Detailed nutritional values of an onion

Values of 100g of raw onion :

Calories40 kcal
Proteins1.1g
Carbohydrates9.3g
of which sugars4.2g
Fiber1.7g
Fats0.1g

Vitamins and minerals

Main vitamins

Vitamin CVitamin B6Folate

Main minerals and trace elements

PotassiumManganesePhosphorus
Ripeness## How to know if an onion is ready ?
A mature onion

Perfectly ripe

A mature storage onion has a firm bulb, dry papery outer scales, and a dry, tight neck after curing.

How to recognize this state :

  • Firm bulb
  • Dry papery outer scales
  • Tight, dry neck
  • No soft spots
  • Skin color typical of the variety
Selection## How to choose onions ?

To choose quality onions :

  • Choose bulbs that feel firm and heavy for their size
  • Look for dry, papery skins and a closed neck
  • Avoid soft spots, mold, dampness, or a strong unpleasant smell
  • Choose yellow for all-purpose cooking, red for color, or white for a sharper flavor
  • Avoid bulbs that are actively sprouting if long storage is needed
Storage and ripening## How to store onions ?

Storing onions

  • Keep whole, cured onions in a cool, dry, dark, well-ventilated place.
  • Do not store them in sealed plastic bags, which trap moisture.
  • Keep onions separate from potatoes.
  • Refrigerate cut onion in a covered container and use it promptly.

Curing

Onions do not ripen like fruit. For storage bulbs, curing is the important step :

  • Let harvested bulbs dry in a warm, dry, well-ventilated place until the neck and outer skins are dry.
  • Do not try to ripen a harvested immature onion for storage.
  • Use green or immature onions promptly.
Health## Health benefits of onions
  • Provides vitamin C
  • Contains dietary fiber that supports normal digestive function
  • Supplies vitamin B6 and folate
  • Naturally low in fat and calories
  • Can add flavor to meals
Origin## What is the origin of onions ?

Origins of onions

Onions have been cultivated for thousands of years and are now grown across many temperate and subtropical regions. Their long history and ability to store after curing helped make them an important culinary crop in many food traditions.

Regions of origin

  • Central and Southwest Asia
  • Mediterranean region
Recipes## Cook onions according to their stage

Unripe

  • Spring onion salad
  • Grilled green onions
  • Quick stir-fry

Perfectly ripe

  • Caramelized onions
  • French onion soup
  • Roasted onions

Overripe

  • Cooked onion soup if still sound
  • Vegetable stock
Gallery## Onions across the world

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F.A.Q## Frequently asked questions
Warnings## Warnings and precautions for onions
  • Discard onions that are moldy, slimy, foul-smelling, or extensively soft
  • Onions can trigger digestive discomfort in some people, particularly when eaten raw
  • Keep onions away from dogs and cats, for whom they are unsafe

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