Rambutan (botanical name Nephelium lappaceum) is an evergreen tree that usually reaches a height of anything between 12 meters and 20 meters. The leaves of this species are alternate and measure about 10 cm to 30 cm in length. Each leaf has anything between 3 and 11 leaflets and each leaflet is about 5 cm to 15 cm in length and 3 cm to 10 cm wide. The leaflets are margined all through. The flowers of rambutan trees are small measuring about 2.5 mm to 5 mm across. The flowers are apetalous, discoidal and appear in straight terminal panicles that are about 15 cm to 30 cm wide.
The trees of this species can either be male or female. The male rambutan trees produce flowers only having stamens and, hence, these trees do not bear any fruit. On the other hand, female trees produce flowers having only functional stigmas and they bear fruits after pollination. There are also hermaphroditic rambutan trees that usually produce female flowers alongside a small number of male flowers. The hermaphroditic trees also produce fruits.
The shape of rambutan fruit varies from round to oval. These single-seed fruits are berry-like measuring about 3 cm to 6 cm (very rarely some fruits grown up to 8 cm) in length and about 3 cm to 4 cm in width. These fruits are borne in loose overhanging clusters, each cluster containing anything between 10 and 20 small fruits. Rambutans have a leather-like reddish skin that is thick with fleshy supple spines, therefore, the name rambutan, which denotes "hairs". Although rare, some rambutans may also be found in yellow or orange color. The color of the flesh of rambutans, which is basically the aril, varies - it may be translucent, very light pink or whitish. Rambutans have a sweet, slightly acidic flavor that reminds one of grapes.
Each rambutan fruit encloses just one small seed that has a shiny brown hue and measures anything between 1 cm and 1.3 cm. The seeds of this fruit have a whitish basal scar. These soft and crispy seeds can be consumed after cooking. According to some myths, rambutan seeds are poisonous and, therefore, unfit for consumption. However, scientific trials involving the use of rambutan seed extract on mice did not reveal any toxicity even when it was administered in relatively higher dosage of 2500 mg/ kg. Apart from consuming the ripened fruit fresh, you can also peel the rambutan fruits, cook and eat them. Both the aril, which is grape-like, and the seeds, can be cooked for consumption. Hence, there is no wastage.
While it is thought that rambutan has its origin in Indonesia, currently this species is found extensively in Malaysia, the Philippines, Thailand, Cambodia, India, Sri Lanka, Australia, and Ecuador in addition to America. In India, this fruit is mostly available in the southern states of Kerala, Karnataka and Tamil Nadu. The fruit has got its name rambutan from an Indonesian word "rambut", which denotes hair. When you add the suffix the "an", it completes the name of the tree -"rambutan". Rambutan is a tropical tree, belonging to the same group of trees that bear fruits such as lychee, longan and mamoncillo.
Usually large trees, rambutans are found growing in tropical regions having high humidity. When young, the color of rambutan fruit is green, but it becomes red on ripening. Ripened rambutan fruits are succulent and have a sweet flavour. While the flesh or aril of the fruit is whitish, it has a thick skin that is covered with supple hairs.
Each rambutan fruit encloses a small, oval-shaped seed, which can be consumed after cooking. In addition, the seeds can also be used for propagating the species. Rambutan trees are usually propagated from their seeds. However, they are also proliferated via the grafting method. Rambutan fruit contains numerous nutritional elements, which are beneficial for our body. This fruit is considered to be a power house of nutrients, including vitamin A, vitamin C, vitamin B complex, protein, dietary fiber and essential elements like iron, calcium, nitrogen, sodium, potassium, magnesium and zinc.
Rambutans are loaded with a variety of nutrition and, hence, it is a very healthy food. In fact, this fruit is a wonderful alternative for processed snack foods. The health benefits of rambutan are not only restricted to the fruit, but other parts of this evergreen tree, including its leaves, rind and bark also offer several health benefits.
Rambutan is considered to be an excellent remedy for dysentery. To treat dysentery, take the rind of 10 fruits, wash them and cut them as per need. Add the rind pieces to three glass of drinking water and boil them till the solution reduces to half its original amount. When the solution cools, strain and drink it twice daily in measures of three-quarters of a glass each time.
For several centuries now, people in Indonesia and Malaysia have traditionally used rambutan, a power house of nutrition, for therapeutic purposes. This fruit has been employed for treating high blood pressure (hypertension), diabetes and various other ailments. In addition to the antioxidants present in vitamin C and beta carotene found in rambutans, researchers at Thailand's Chiang Mai University have discovered that the pulp, seed and rind of the fruit enclose flavonoids, or plant-based potent antioxidants. It is thought that specific types of flavonoids help to lower the levels of blood cholesterol and, at the same time, possess anti-inflammatory and anti-carcinogenic properties.
The rind of rambutan encloses various organic compounds and gallic acid is prominent among them. This compound works in the same manner as other free radical scavengers, thereby helping to protect our body from oxidative damage attributed to free radicals. Gallic acid is also believed to be powerful in combating cancer. Compared to other fruits like pomegranate, rambutan has widespread antioxidant activities. The extract of the fruit's rind has the potential of being promoted as a health supplement.
Apart from flavonoids, rambutan is loaded with vitamin C. Consumption of 10 or 12 rambutans supplies our body with roughly 75 mg to 90 mg ascorbic acid, which is more than twice the daily recommended amount of this nutrient. Vitamin C is an essential antioxidant that protects the cells in our body from damages caused by free radicals. In addition, this nutrient also facilitates the assimilation of iron by the body.
This tropical fruit also encloses small amounts of copper, an essential mineral needed by the body to produce white blood cells (leukocytes) and red blood cells (erythrocytes). It also contains trace amounts of manganese, which is essential for the body to produce as well as activate specific enzymes.
Just one serving of rambutan fruit serves as a wonderful source of iron. Iron present in our food helps to promote the appropriate amount of oxygen in the body. This, in turn, helps to end drowsiness and fatigue caused by anemia. This condition is attributed to deficiency of iron in the body.
In addition to the above mentioned nutrients, a single serving of rambutans also provides us some amounts of phosphorus, which is about 4.3 percent of our daily recommended intake of this essential mineral. Phosphorus aids in eliminating waste substances from the kidneys. It is also necessary for the development, mending as well as the maintenance of the cells and tissues in our body. Rambutan also contains trace amounts of calcium. Together, calcium and phosphorus work to make our teeth and bones stronger.
Apart from the nutritional benefits of rambutan, this fruit also has a number of therapeutic uses. Eating rambutan may help in eliminating parasites in the intestines and, at the same time, aids in alleviating the symptoms related to diarrhea. In Malaysia, many traditional healers use some parts of rambutan fruit to treat fever. However, it is advisable that you should consult your physician prior to using the rambutan fruit to treat any illness or disorder.
Despite the fact that rambutans usually grow in the tropical regions like Costa Rica, Hawaii, Panama, Puerto Rico and several countries in Southeast Asia, this nutritional fruit is available at a number of Asian markets as well as some major grocery stores in North America and the United Kingdom. If possible you should always buy rambutans that are still attached to their stem, because they are believed to possess higher nutritional and culinary value compared to the fruits that are detached from their branches.
If you wish to make optimal use of rambutan's flavour and nutritional properties, it is advisable that you consume this fruit raw. Just remove the hairy skin of the fruit and put the fruits white succulent flesh in your mouth. However, you need to be careful and not eat the bitter flavoured seed of rambutan, which is concealed within the white flesh.
Apart from eating the fruit raw, you can also use the rambutan with its peel and seeds in fruit salads and smoothies. This nutritional fruit can be used in place of lychees. You can also extract the juice of rambutan and spice it up with some vanilla or cinnamon. Believe it or not, it is definitely worth trying.