Wednesday, October 31, 2012

All About Longan



Longan is the subtler cousin of lychee. Scholar and professor, G. Weidman Groff, states that longan may be less important than lychee in China’s cuisine, but longans are of greater importance in Chinese medicine. Indeed, despite the nation’s extensive cultivation of longan for over 2,000 years, China is still a net importer of the fruit.

Origin of Longan
Longan’s origin is southern China, specifically the provinces of Kwangtung, Kwangsi, Schezwan, and Fuklen. Longan’s literal translation is “dragon eyes.” Though some scholars date the fruit’s entry into India circa 1790, scientists from the World Agro Forestry Center point to passages from ancient Indian literature and state the fruit is native not only to China, but to the forests and hills of Assam and the Garo hills.

Today, longans grow throughout Thailand, Cambodia, Laos, and Taiwan, and they are exotic in parts of the Caribbean and the US. In Australia, scientists have attempted to hybridize the fruits by cross-pollinating varieties of lychees and longans.


As of 2006, commercial growing countries include Australia, Thailand, Taiwan, the US, Vietnam, and China. Thailand is the top producer of longans, with the Chang Mai as the most prolific region.

Availability of Longan in India
Longans are capable of growing throughout India, from the south up to the northeastern borders. As explained in the book, “Minor Fruit Crops in India,” the trees grow best in tropical regions with mild summers and winters, and even rainfall. Bengal is a prominent longan grower, although India still imports much of its supply from Thailand. This exchange between countries was facilitated by trade talks occurring in 2006 and 2012. Such agreements aimed at lowering tariffs and increasing longan’s marketing efforts in India.


Longan season in Southeast Asia is mid to late summer, from July through September. There is an off-season period in Thailand from November to early February as well.



Where to find Longan in India
Though longans are not as popular here than in other Asian countries, they are still sold throughout India when in season. Most stores sell them like lychees in stick-like clusters, but upscale markets purvey pre-picked fruits in plastic-wrapped containers. 


Don’t let vendors sell you longans as “lychees.” They often use the name interchangeably, despite clear and obvious differences between fruits.

Checking for Ripeness in Longan
Longans do not ripen off of the tree; thus, any fruits purchased from the market should be ready for immediate consumption.

The ripeness of longan is evident in its shell. Sometimes the fruit’s firm skin requires “cracking,” and if the environment is humid, the pliable skin requires gentle peeling. The fruit is edible in both cases, although the fruits with pliable skin may be nearing decay.


Choose longan with dry, even brown skin, and avoid cracked fruits with mold near the stem. If the skin looks moldy or mushy, the fruit inside is likely overripe. Ripe longan flesh is white and translucent. As it spoils, the flesh turns purple and ultimately, brown.

Taste of Longan
Perfectly ripe longans are sweet, refreshing and clean with hints of floral nectar. The texture is similar to a grape, as is the flavor: If the grape was stripped of its tart skin, and was more subdued in its sourness and sweetness, the remaining flavor would resemble a longan.

Overripe, purple-fleshed longans develop a savory, musky, pungent flavor resembling garlic and onions. These longans are evident by their mushier, soft and pliable skin. Gradually, these unusual flavors yield to a fermented, unpleasant taste.


Dried longans have very different flavors than fresh longans— dried fruits taste like raisins and dates.

Dried longan

Nutritional Value of Longan
According to the USDA nutrient database, 100g of edible longans contain the following nutritional profile:

60kcal
15g Carb
1.1g Fiber (4% RDI)
.1g Fat (negligible)
1.3g Protein (3% RDI)
84mg Vitamin C (140% RDI)
Thiamine (2% RDI)
.1mg Riboflavin (8% RDI)
.3mg Niacin (1% RDI)
10mg Magnesium (2% RDI)
21mg Phosphorous (2% RDI)
266mg Potassium (8% RDI)
.2mg Copper (8% RDI)

.1mg Manganese (3% RDI)



Health Benefits of Longan
Longan has several uses in traditional remedies. In Chinese medicine, it is a warming agent and helps the heart and spleen. According to the book, “A Materia Medica for Chinese Medicine,” longan provides the following benefits:

It treats yin, and remedies insomnia, agitation, palpitations, forgetfulness, excessive sweating and panic attacks. As a tonifier of qi, longans remedy exhaustion, reduced appetite, edema, postpartum fatigue, and weak constitution. The fruit also promotes healthy digestion and is a calming agent.

Longans are also renowned in Indian and Chinese cultures for their blood-boosting benefits: the fruits stave off anemia and boost iron absorption. Furthermore, the high antioxidants improve skin health and keep signs of aging at bay.

Several scientific studies have been published regarding longan’s health benefits.
--A 2012 study published in Fitoterapia found that longan seeds are an antifungal, as they fight several fungus strains responsible for yeast infections.
--Food Research International published a study citing the fruit’s pharmaceutical benefits, including pain relief from swelling, memory enhancement, and anticancer activity.
--A study published in Phytotherapy Research shows the seed extracts may be an anti-fatigue agent.
--According to a study published in Food Research International, longan’s flower extracts fight fatty liver disease.
--The Evidence Based Complementary and Alternative Medicine published a study concluding that longan fruit acts as an anti-inflammatory agent and natural antioxidant.
--According to a study published in a Swiss-based publication, Molecules, a protein complex in longans has potential as an immunotherapeutic agent.

--A 2009 study published in Innovative Food Science and Emerging Technology reports the fruit’s antioxidants exhibit anticancer activity.

How to Open/Cut:

Peel the skin to expose the translucent flesh. Once fully peeled, eat the marble-sized fruit and take caution to spit out the large, glossy black seed in the middle of the longan. Because of its large seed, longans are not suitable for toddlers. However, it is not difficult to peel the longan, cut it in half, and remove its large seed manually.



Storage:
If storing at room temperature, consume within a few days. Otherwise, keep in a plastic bag with a slight opening to reduce condensation and place them in the refrigerator--they’ll remain fresh for a week or two.


To freeze, peel and deseed the fruits. Keep in a freezer bag, and use within the year.  

Longan Recipe Ideas and Uses:
--Stew longans in sugar and syrup to preserve the fruits: they’ll keep for a few months.
--Juice longans by pulsing in a food processor and straining. Add the sweet, refreshing juice to sorbets and cocktails. The fruit juice also goes well in coconut ice cream.
--Slice the fruit as part of a tropical salad, and include with pineapple, carambola and a soy-based dressing.
--Incorporate dried longans as a raisin substitute in baked breads. Though unconventional, split pieces of fresh longan may be added atop tarts, flans and cheesecakes.
--Add dried longans to soup: a Cantonese classic tong sui soup entails making a longan “tea” by simmering dried fruits with ginger, brown sugar, potato chunks and pandan leaves.
--During the Chinese New Year, it’s common to serve a soup made from lotus seeds, gingko nut, dried longans, brown sugar, persimmon, sterculia seeds, water, and pandan leaves.
-- Whisk bananas and peeled loquats into standard custard recipes.
--Add halved longans to gelatin recipes, as the fruit’s gelatinous texture complements that of jello’s.
--Stir chunks of the fruit into vodka jelly shots.
--Dry the flesh over a slow, open fire and add the smoky fruit to soups
--Serve cut longans with cantaloupe or other melons.


In China, the longan’s seeds are used like soapnuts on account of their high saponin content. Thus, they’re found as an ingredient in a few shampoo and soap bottle brands.

Longan, mango, pomegranate popsicle from
Rasamalaysia.com

Flavor Complements:
Lychee, longkong, langsat, grapes, rambutan, persimmon, java apple, mangosteen, coconut meat, passion fruit, pineapple, pomegranate, citrus, Asian pear, carambola, dragon fruit, guava, giant granadilla, wampee

Herbs, spices, and oil: raisins, brown sugar, vanilla, lemon juice, salt, soy sauce

Random Facts:
A rare, spiky green longan variety grows in Borneo. Though it looks bizarre, locals laud the fruit for its exceptional flavor.



Scientific Name:
Dimocarpus longan
Dimocarpus longan x Melasianus

Other Names:
Ansphal
Tokra
Puvatti
Mulay
Poripuna

Oomb





5 comments:

  1. Longans are grown all throughout Indian, from the south up to the east boundaries. Bengal is a popular farmer of the fruits. As explained in the book, “Minor Fruit Plants in Indian,” the plants grow best in exotic regions with light summertime and winter seasons, and even rain fall.buy rs gold

    ReplyDelete
    Replies
    1. Hi,
      May i know whether Longan would suit as a commercial crop in tropical rainy regions where ther average rainfall is above 300mm and has an annual temperature between 25 degrees to 35 degrees? ? Or does it prefer subtropical regions?

      Delete
  2. hello

    i have a longan farm in Thailand and im looking for a experienced indian farmer can take care my tree.
    If you need more information you can contact me by mail : goldlongan(at)hotmail.com

    ReplyDelete
  3. Which part in India it is growing? Where in Bengal??

    ReplyDelete
  4. Can someone tell me if it will grow in (Goa) tropical climate where temperate ranges between 20-25 to 30-35 degrees C and average rainfall is 995 mm??? Also, will Langsat and Lychee grow. I read that they require cool winters for flowering but will 20-25 degrees C will do the job?

    ReplyDelete