Bitter orange is the sour orange of Seville marmalade, a natural hybrid of pomelo and mandarin. It looks like an ordinary orange but the pulp is too sour and bitter to eat fresh. Its peel, flowers and leaves are valued for aroma: the flowers give neroli oil and orange-flower water. In Tamil Nadu, sour oranges sold as naarthangai go into pickles, though that name covers more than one citrus.
- Botanical name
- Citrus × aurantium L.
- Family
- Rutaceae
- Tamil
- Kasappu orange
- Hindi
- Khatta sangtra
- Parts used
- Ripe fruit, Peel
- Habit
- Hybrid sour orange; Tamil naarthangai is a shop word
- Last updated
- 2026-10-27
How to recognise Bitter orange
It is a small, rounded evergreen tree, often with long thorns, and glossy, strongly scented leaves.
The leaf stalk is broadly winged, much more so than in sweet orange, a useful way to tell the two apart.
Fragrant white flowers open in spring clusters and are heavily perfumed.
The fruit is round, orange-red and rough-skinned, with a thick, bitter peel and very sour, seedy flesh.
Sweet orange, Citrus sinensis, has narrow leaf wings and sweet flesh.
Traditional use of Bitter orange
Kitchen
Seville oranges are boiled with sugar into marmalade, and dried peel flavours orange liqueurs and bitters.
European food practice
Kitchen
In South India sour orange is cut and salted for oorugai pickle, and the juice is used like lime.
Tamil household practice
Perfumery
Flowers are distilled for neroli oil and orange-flower water, and leaves and twigs give petitgrain oil.
Mediterranean perfume practice
Modern notes on Bitter orange
Bitter orange extract contains synephrine, a stimulant that weight-loss supplements added after ephedra was banned in the United States in 2004.
Reports of high blood pressure, fast heart rate and strokes have been linked to these supplements, especially when combined with caffeine.
Like grapefruit, the juice contains furanocoumarins that can raise blood levels of some prescription drugs.
Growers once used it widely as a rootstock, but it fell out of favour because grafted trees are highly vulnerable to citrus tristeza virus.
Bitter orange safety
Avoid bitter orange supplements if you have heart disease or high blood pressure, or take stimulants. Ask a pharmacist before taking the juice with regular medicines.
Ecology and sourcing
It arose in South-east Asia and reached the Mediterranean through Arab traders around the tenth century.
Seville still has thousands of bitter orange street trees, and most of the fruit is exported to Britain for marmalade.
The scented flowers draw bees, and orange-blossom honey partly comes from it.
Related plants
Also in Rutaceae
Questions about Bitter orange
Can you eat bitter orange fresh?
Rarely. The flesh is too sour and bitter; it is cooked, pickled or juiced.
Is Bitter orange naarthangai?
Often, but naarthangai is a shop name used for more than one sour citrus.
What is neroli?
An oil steam-distilled from bitter orange flowers.
Are bitter orange diet pills safe?
They carry heart risks, especially with caffeine. Many doctors advise avoiding them.
How do I tell Bitter orange from sweet orange?
Check the leaf stalk: bitter orange has broad wings.
Sources
- Citrus × aurantium L. — Plants of the World Online, Kew (search) (accessed 2026)
- Wikidata item Q147096 (Citrus × aurantium)
Educational page about a plant. It is not medical advice, not a diagnosis, and not an offer to sell. Traditional use is historical. If you need care, ask a licensed clinician. Questions: hello@meevamed.com.