Monday, April 1, 2013

All About Citrus aurantium (Sour Orange)

Origin of Sour Orange
Sour orange’s prehistoric origins are located in Southeast Asia, most notably in China and India. Early explorers brought the fruits via boat to the islands of Fiji, Guam and Samoa. The Arabic countries were the next to receive the fruit circa 9th Century, followed by their mentions in Italy around 1,002 AD. However, the appearance of citrus trees in Italian mosaics indicates that the fruit may have been growing in Italy around Constantine’s rule as early as 330AD.

Even today, most of the commercially grown Citrus aurantium fruits are in Italy and France, while Morocco, Haiti, Taiwan and Cyprus grow the fruits on a much smaller scale. Sour oranges are naturalized throughout diverse regions of the world, from Central America to Tropical Africa.

While various types of oranges have existed in India for centuries, the book, “Citrus Classification” explains that the Assam government introduced India’s unique variety, Citrus karna, circa 1904.

Availability of Sour Orange in India
Sour oranges grow all over the moist, warm regions of the country up to an elevation of 1,000 meters. The Eastern Ghats and hill ranges of India are just a few examples of the regions in which it’s cultivated. Like most other citrus fruits, it’s also grown mainly in Guntur and Tirumala, Andhra Pradesh, the Khasi hills, Cachar, and in its wild state, Naga. Other states cultivating the fruit are Tamil Nadu, Kerala, Karnataka, Maharashtra, Punjab, West Bengal and Goa. While India’s main sour orange variant is karna, the country grows other famous varieties such as bitter, Seville, and Bergamot.

Where to find Sour Orange in India

The sour oranges grown in India seldom reach the consumer in their whole fruit form. Rather, they come as manufactured products as syrups, flavoring agents, health supplements, candies, oils or extracts. Nonetheless, those living in the warm, tropical regions of India can easily grow the fruit in their yards and gardens. Furthermore, a few large cities like Delhi grow the trees for landscaping, thus making it possible to find while strolling through parks, avenues, and city monuments.

Citrus karna

Checking for Ripeness in Sour Orange
Some types of sour orange possess green skins, some yellow, while others are deep orange. This means the fruit’s best indicator of ripeness is the fragrance and aroma of its skin. The best oranges have incredibly oily, zesty peels that practically burst with a citrusy aroma. Look for fruits that feel heavy for their size, and avoid those with hard, brown skin and small pores.

Taste of Sour Orange

Like amlas, lemons, and limes, a sour orange cannot be eaten in their raw form—it’s extremely acidic, bitter, and, as its name suggests, sour. Drinking the juice requires adding copious amounts of water and sweetener. However, cookbooks are chock full of recipes highlighting the fruit’s light, zesty, citrusy and aromatic qualities.

Nutritional Value of Sour Orange
As per a sample taken in Guatemala and El Salvador, 100g of sour orange contains the following values:

83-89.2g Moisture
.6-1g Protein
.1g Fat
9.6-15.3g Carbohydrates
.4g Fiber
.5g Ash
18-50mg Calcium
.2mg Iron
12mg Phosphate
200IU Vitamin A
100mcg Thiamine
40mcg Riboflavin
.3mg Niacin

45-90mg Ascorbic Acid


Health Benefits of Sour Orange
Sour oranges have a number of health benefits—so many, in fact, that bitter orange extracts are sold as a health supplement. When the US’s Food and Drug Administration banned ephedra, many turned to bitter orange extracts as a weight management supplement. This is because the extracts contain compounds structured similarly to ephedrine, namely synephrine and norepinephrine.

According to the book, “Indian Medicinal Plants,” sour orange’s peel traditionally acts as a laxative, emmenagogue, and stomachic. The leaves manage arthritic symptoms and bronchitis. Even the flowers have medicinal uses—as an aqueous extract, it treats scurvy, inflammation, fever, and hysteria. The fruits remedy fever and enlarged spleen.

In aromatherapy, neroli (an oil made from sour oranges) treats a number of ailments. As per the book, “Aromatherapy: Essential Oils for Vibrant Health and Beauty,” neroli calms heart palpitations, acts as a calming agent, soothes stress, alleviates menstrual cramps, and ameliorates skin irritation arising from eczema and dermatitis. European practitioners use the oils for patients experiencing insomnia and nervousness.
Neroli oil
Scientific studies reveal amazing additional health benefits:
--A 2012 study published in the BMC Complementary and Alternative Medicine found that Citrus aurantium flavonoids inhibit apidogenesis, the process in which the body converts and multiplies fat cells. This research supports the extract’s use as a weight loss supplement.
--A 2013 study published in the Journal of Agricultural and Food Chemistry found that sour orange peel may have therapeutic benefits based on its ability to reduce swelling in rats. 
--A 2012 study published in Phytotherapy Research indicates that sour orange’s flavonoids have anti-inflammatory properties.
--When testing for the supplement’s safety, a 2013 study published in Food and Chemical Toxicology shows no adverse health effects from taking bitter orange extracts.
--Amazingly, a 2011 study published in Evidence Based Complementary and Alternative Medicine found that sour orange flavonoids may be an effective chemo preventative agent against gastric cancer.
--Another 2012 study published in Food Chemistry found similar anti-cancer effects against lung cancer cells.
--A 2012 study published in the International Journal of Oncology found the peels have anticancer activity on human leukemia cells.

--A 2011 study published in Revista Brasileira de Anesteseologia affirms sour orange blossom’s use as a relaxant: the group that took oral tablets before a surgery showed less anxiety than the placebo group.

How to Open/Cut:
For sour orange juice, simply cut the fruit in half and squeeze the fruit. If a commercial juicer is on hand, slice away the rind of the whole fruit using a sharp paring knife, and then drop the fruit in the processor.

Because there are so many medicinal benefits in the rind, use a citrus rinder to make small fine shreds of the peel. Use in baked goods recipes or even atop salads. Or, cut the rind into fine, match stick-sized pieces for the purposes of candying the peel.


Keep sour oranges at room temperature, as they will retain their juiciness best when kept out cool climates. They will keep for two to three weeks. If willing to put in a bit more effort, individually wrap the fruits in newspaper and place in a cardboard box. Store the box in a low-humidity refrigerator with a temperature nearing 40F. These will keep for six to eight weeks. While the fruits will not tolerate freezing, it’s possible to freeze the juice as ice cubes and use as needed. They will keep for six months. Store orange oil in dark-colored glass away from direct sunlight. Keep in a cool location.

Candied orange peel from
Ciao Chow Linda

Sour Orange Recipe Ideas and Uses:
--Make sour orange salad dressing by including the juice with some olive oil, sesame seeds, soy sauce and coconut oil.
--Squeeze sour orange juice into glazes and marinades
--Make marmalade, as the peel makes an exceptionally tasty addition
--Instead of making lemonaid, substitute the lemons for sour orange.
--Include the juice in sodas for an alternative to artificially colored and flavored orange soda.
--Add sour orange juice to sweet bread, pancake and cupcake batter.
--Make a glaze from sour orange

Certain types of sour oranges are famous not for the juice, but the extracts and oils from parts of the fruit. For instance, the oils from the peels of bergamot oranges make world-renowned perfumes, aromatherapy medicines, liquors, teas, and even flavors for smokeless tobacco.

The blossom of the bitter orange tree is the chief agent making neroli oil, a compound renowned for its gorgeous aroma with floral, sweet, spicy and distinctly citrus notes.

Flavor Complements:
Lemon, lime, banana, pineapple, mango, strawberry, peach, noni, apricot, pomegranate, date, fig, grape, guava, cherry, coconut, amla, persimmon, kiwi, kumquat, nungu, papaya, passion fruit, pomelo, santol, soursop, wood apple

Herbs, spices, and oil: olive oil, lemon juice, lemon rind, salt, pepper, rum, nut butter, chili, fennel, rosemary, ginger, cumin, cinnamon, nutmeg, raisin, maple syrup, nut milk, pistachio, almond, walnut, coconut oil, vanilla, chocolate, champagne

Converted British orangerie

Random Facts:
Neroli oil is a strongly suspected compound in the top-secret Coca Cola formula.

Amazingly, Europe didn’t receive sweet oranges (or any other type of citrus, for that matter) until 500 years after the arrival of sour oranges.

Sour oranges didn’t have the best reputation amongst noble classes in the medieval period, as they were considered peasant food. Ironically, orangeries—greenhouses to grow citrus fruits—became en vogue amongst European aristocracy between the 17th to 19th centuries.

Binomial Name:
Citrus aurantium
Citrus jambhiri
Citrus penivesiculata

“Sour orange” is one of the broadest terms to use for an orange with a sour, pungent, mouth-puckering quality. With approximately 1,500 types of citrus fruits growing in the country, pinpointing which types constitute this broad definition is nearly impossible.

Even karna’s citrus classification is debatable. According to R.C. Woodford’s book, “Citrus Classification,” some botanists proposed naming the fruit, Citrus karna while others thought Citrus aurantium var karna was ideal.

Other Names:
Citrus karna
Gambhru khatta
Kharna katta
Mallikanarangi (Siddha/Tamil)
Swadu-naringa (Sanskrit)

Related Fruits:

Any fruit in the Citrus genus: citron, orange, calamondin, mandarin, sweet lime, etc.


  1. I always wondered if bergamot oranges were edible; your post has answered my question, thanks :)

  2. Wow! i love citrus fruits. Every time, we have oranges in our house, i am the one who makes eat :) Thank you for sharing this wonderful kind of blog. It is totally amazing! By the way, my alternative treatment for cancer clinic likes reading this.

  3. Very informative article to educate people about cultivation ...

  4. We have these in abundance in Costa Rica and I can't drink water w/o half a squeezed sour orange - called limon in Latin America. Thanks for the info!

  5. We have these in abundance in Costa Rica and I can't drink water w/o half a squeezed sour orange - called limon in Latin America. Thanks for the info!

  6. Nice information, you people can checkout the other natural ingredients like vegetables, herbs, fruit juices as I love having Pure Goji Berry Juice that is really interesting and healthy to have in breakfast. It helps me to attain energy that lets me work well fro the whole day.


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  10. we have a fruit called "Herelekai" in karnataka. is this bergamot orange?