Real Food Encyclopedia | Lychees, Rambutans and Longans
From the outside, lychees (Litchi chinensis), rambutans (Nephelium lappaceum) and longans (Dimocarpus longan) don’t look very similar: Lychees have bumpy pink skin, while rambutans have a deeper red shell of long, soft spines. Longans, the smallest of the bunch, are smoother and brown. Once peeled, however, the fruits all look and taste similar, with fragrant white flesh surrounding a large seed. The fruits’ sweet, floral flavor is often compared to the smell of roses, though they are subtly different: Lychees are the sweetest and most fragrant, while longans have a more tart, musky flavor.
While fresh lychees and rambutans are increasingly common in supermarkets around the world, fresh longans are harder to find outside of the warm areas where they grow. However, all three can be found dried, canned or frozen in Asian groceries or specialty stores. The canned versions, along with lychee juice, are increasingly popular worldwide as flavorings for drinks and desserts.
What to look for when buying lychees, rambutans and longans
When buying fresh lychees and rambutans, look for pink to red skin and fruit that feels firm but not hard. Tan or squishy fruit may be past its prime. For rambutans, the spines should be flexible and soft — dry or brittle spines are a sign that the fruit is old. Ripe longans are often sold in bunches on the branch. They will be slightly firmer than the others but will be tan-colored when ripe. For all fruits, avoid any with broken skin and obvious blemishes.
Sustainability of lychees, rambutans and longans
These three fruit varieties can suffer from a variety of insect pests, fungal diseases and other issues that may lead growers to use pesticides. Occasionally, these are used in a quantity that violates import standards; Australian researchers found pesticide residues above permissible levels in lychees from China, including very high levels of a fungicide that is a suspected carcinogen. Pesticides are inconsistently regulated in some countries that produce these fruits, which can also be a concern.
A string of child poisonings in India and Bangladesh, which was originally blamed on compounds in the fruit, was subsequently attributed to the use of illegal pesticides in orchards. Children in the area had taken to peeling the fruit with their teeth, exposing them to dangerous levels of pesticides.
Herbicides like glyphosate and paraquat, which damage wildlife around farms, are sometimes used to control weeds in commercial orchards for these fruits. Additionally, all three fruits are commonly treated with synthetic fertilizers, especially when produced commercially for export. Backyard growers and smaller producers may use fewer or no chemicals, especially on young trees.
Organic versions — both fresh fruits and processed products — are increasingly available, so, if possible, seek these out to avoid chemical concerns. If you live in an area where these fruits are grown, look for a local vendor who can talk to you about their growing practices.
Like many fruit crops, lychees, rambutans and longans can be labor-intensive to harvest. In countries where the fruits are grown for export and processing — particularly Vietnam and Thailand — working conditions for agricultural laborers can be poor, with long hours and high risks of chemical exposure.
Different varieties of lychee, rambutan and longan may be available throughout the year, but the prime season for lychees and longans tends to span late spring through early fall. Rambutans are more available through the fall and winter.
The lychee is native to Southeast China and Northern Vietnam, where it has been cultivated for more than 3,000 years. Wild trees can still be found in these regions. The fruits didn’t become widespread until the 1700s, when they were brought to India, the Caribbean and even greenhouses in Europe. While it is now enjoyed in tropical regions around the world, the greatest diversity of lychee varieties is still in Southeast Asia. Longans come from the same region of China, but are found at higher altitudes; while they grow in many tropical areas, they fruit best in places with cool, non-freezing winters.
Rambutans originated in a different part of Southeast Asia, around present-day Malaysia. Arab traders and, later, Dutch colonists, spread the fruit through East Africa, Indonesia and South America. While the fruit has also spread through tropical and subtropical areas around the world, it is not nearly as well-known or popular as the lychee.
Today, China, India and Vietnam grow most of the world’s lychees, and most imported lychees in U.S. markets (as well as dried and canned lychees and lychee juice) come from China and Vietnam. Rambutans and longans are also produced in these countries, though Thailand also exports a large amount of the fruit.
Lychees are grown on a limited scale in the U.S., although they require frost-free conditions to thrive, limiting their growth to South Florida, Hawai’i and parts of California. Longans can also be found in these areas, while rambutans, which need more consistent tropical weather, are mostly limited to Hawai’i. They are all found as backyard trees, though they can also be found at farmers’ markets in these areas.
Eating lychees, rambutans and longans
Lychees, rambutans and longans have a relatively short shelf life at room temperature. Ancient Chinese texts say a lychee loses its color one day after picking, its fragrance on the second day, and its sweetness on the third. This ancient advice holds up today: All three fruits should be eaten as soon as possible after picking, as they do not ripen further off the tree. Fruits can also be kept in the refrigerator for up to seven days, but will begin to go mushy and sour if they are kept past their peak.
All three fruits are delicious eaten fresh with no accompaniment. They can be peeled like small citrus. The fruits all contain a large seed in the center, which you can either remove before eating or spit out after you’ve eaten the sweet part of the fruit.
They are all delicious additions to fruit salads, smoothies or drizzled with syrup and eaten with ice cream. Fresh, canned and dried fruit can also be added to baked goods like cakes, cupcakes and tea cakes. The fruits freeze well, making them a good candidate for sorbets and ice creams. In recent years, lychee juice has become a staple in some bars, thanks largely to the sweet “lycheetini.”
Given their Asian origin, all of the fruits are widely used in cuisines across Asia. Different kinds of the sweet Vietnamese soup che are made with both dried and fresh versions for a sweet, refreshing treat. In India, cooks often use lychee in dairy-based desserts like kheer and rabdi, where the floral flavors complement the sweet richness of condensed milk. Lychee jellies are a popular addition to bubble teas, which originated in Taiwan but have become popular across the world. The fruits are not just limited to sweet dishes. In Chinese cuisine, lychees are sometimes cooked with chicken in sweet, tangy sauces, and are also used in stir-fries. Similar dishes can also be made with pork and other meats.
Lychees, rambutans and longans are commonly dried in Asia. Referred to as lychee nuts, the fruits can also be dehydrated at home with a fruit dehydrator or in an oven.
Jams can be made with any of the fruits, which will keep for a few weeks in the refrigerator.
You can also freeze these fruits. This can be done by placing the whole, skin-on fruits in a sealable container in the freezer. They may discolor over time but will maintain their flavor for several months. You can also peel and deseed fruits before freezing, but they will be less flavorful after thawing.
Lychees, rambutan and longan are all similar in nutritional content. Like many tropical fruits, they are high in Vitamin C. Lychees are especially rich in Vitamin C, providing more than the daily recommended value in a single 100 gram serving.
Lychees were briefly suspected of poisoning several children in India and Bangladesh, which led many news outlets to declare they could be poisonous. In these cases, children had consumed unripe lychees and suffered from a severe drop in blood sugar, followed by convulsions, fever and death. Doctors concluded that deaths occurred largely because the children were also malnourished. Subsequent studies showed the illnesses were partially the result of illegal pesticide usage in orchards and not due only to the fruit itself. With all this in mind, health experts say ripe lychees are perfectly safe to eat, but that children and people who have low blood sugar should be careful eating too much unripe fruit. They also advise against eating the fruit immediately after fasting.
Top photo by Claudio Baldini/Adobe Stock.