Useful information

Carambola - star fruit

Carambola, better known as "Starfruit", appeared on the tables of Europeans quite recently and attracted the attention of consumers primarily with its unusual shape of the fruit. The oval fruits are as if cut by deep grooves that form ridges, so that decorative stars are obtained when the fruit is cut crosswise.

Foggy past and bright present

Carambola (Averrhoa carambola) tree of the oxalis family (Oxalidaceae), occurs wildly in Indonesia, Malaysia, India, Bangladesh, the Philippines and Sri Lanka. Grows in the tropics and subtropics, rising to heights of 1200 m above sea level. Requires high humidity (over 1800 mm / m²).

The place of origin of carambola has not yet been clarified, it is assumed that it is Sri Lanka or the Moluccas (Indonesia). Carambola has been cultivated for centuries in the Indian Peninsula and Southwest Asia. Favorite planting sites in these regions have been partially preserved even now, but thanks to acclimatization, the area of ​​distribution of culture has expanded significantly. Now this plant can be found in China and Queensland (Australia), in Ghana (West Africa), on the islands of Oceania, in Brazil, the USA and Israel.

Leading carambola producers are Australia, India, Israel, Malaysia, Philippines, Guyana and the USA. The world leader in terms of production is Malaysia, which supplies fruits to Asia and Europe.

The Russians got acquainted with the "star" fruit quite recently - at the end of the 20th century. Fruits are supplied to Russia from Israel, Brazil and Thailand.

Botanical portrait

Carambola with fruits in the greenhouse. Photo: R. Brillliantova

Carambola develops slowly, growing into an evergreen tree up to 10 m high. A dense strongly branching crown with a single or many trunks rustles with huge odd-pinnate leaves. The crown width of the tree reaches 6.0-7.6 m. The plant is quite capricious and demanding on environmental conditions. Being a native of the tropics, it requires maximum illumination, painfully tolerates a temperature drop below + 18 ° C, does not tolerate strong winds, requires a well-drained soil with high humidity with a pH below 7, in addition to the mandatory content of a number of trace elements in the soil and an annual three-fold fertilization. and quickly responds to "living conditions", expressing his displeasure with the collection of leaves.

The optimal temperature regime for growth is + 20 + 35 ° С, at temperatures below + 18 ° С, growth stops. At a temperature of -1-0 ° C, young leaves die off, when the temperature drops to -4-6 ° C, the tree receives significant frostbite, including the trunk.

A tree is planted in a non-shaded place, providing constant access to sunlight, at a distance of 7.5-9.0 m from other trees and buildings. Close placement interferes with the normal development of the tree and obscures adjacent trees. The middle of the deciduous tent at a height of 1-2.1 m is the main fruitful zone of an adult tree, so the lower branches are never pruned.

Carambola does not tolerate constant winds. The leaves in such conditions turn brown, deform and fall off, the trunk dies off.

The wood of carambola is white, fine-grained, of medium hardness, over the years it turns red. It is used for the production of furniture and wooden structures.

The pinnate leaves of the plant are soft, smooth on top and pubescent on the bottom. A leaf 15-40 cm long consists of 2-5 pairs of opposite oval leaflets 1-9 cm long and 1-4 cm wide with an apical leaf at the end of the petiole. Carambola collects leaves after sunset, and in the daytime signals any unfavorable conditions. Such plant movements are called niktinastia, they are caused by changes in light and temperature, which is observed at the onset of the evening.

Carambola leaves. Photo: Rita Brillliantova

Branching is sympodial lateral, when the leaves successively, alternating on the right and left, move away from the branch and form the horizontal plane of the branch.Carambola is unique in that both shoots and branches retain the ability to bloom, they can bloom consistently. The tree in nature begins to bloom 3-4 years after planting.

The year-round flowering has made carambola an ornamental plant, with the intensity of flowering being different throughout the year. Small fragile fragrant lilac-pink flowers with red veins on red legs are collected in small panicles, which are attached in the leaf axils on young shoots or thicker branches without leaves. Flowers 0.6-1.0 cm in diameter have 5 petals and sepals. The flowers are edible, have a sour taste, and on about. Java is added to salads.

The tree bears fruit twice a year: from April to May and from September to October. The rest of the time the plant can produce single flowers and fruits.

The tree is an excellent honey plant. Some varieties are self-pollinated, others require mandatory cross-pollination. Some varieties that bloom intensively for a short time require cross-pollination with varieties that bloom for a long time in order to obtain a good yield. Cultivars such as Fwang Tung, Golden Star, Arkin yield good yields when planted in dense clusters, taking into account the need for cross-pollination.

Despite the fact that the characteristics of the plant include year-round flowering, from which year-round fruiting should follow, nature always makes its own adjustments to such wasteful plans. In fact, the fruiting season depends on environmental and maintenance conditions. With the correct use of agricultural technology, a tree can even give 3 harvests per year.

Every year in September, the top of the crown is pruned so that it does not exceed 3.5-4.0 m and is not exposed to the destructive effect of winds. Periodically cut dry branches and prune vertically growing shoots, thinning and forming a crown. On plantations, pruning is used to stimulate flowering and fruiting by a certain date.

Pruning causes the tree to bloom after 21 days, followed by fruit ripening after 60-75 days. These dates are observed during the warm season. Traditional pruning in August is done to increase the October harvest. If pruning is done during the cooler months of the year (November-December), the crop may be ripe by February-April or even June. The delay is caused by slow formation and ripening of fruits in an uncomfortable temperature regime (from January to March). The shoots bloom all the time while the fruits are forming.

The following pruning methods are most often used: thin young twigs are shortened to 30-45 cm, or a larger branch is freed from all lateral shoots, or lateral leaves are cut, leaving the base of the petioles about 1 cm in size.

In nature, the tree begins to bear fruit in the 3-4th year, on plantations this period is reduced by grafting and cutting to 2 and even up to 1.5 years.

Removing unripe fruits in November-December stimulates the tree to grow leaves and induces early spring flowering and fruit ripening in June.

Yields during the first two to three years are small: from 4.5 to 18 kg of fruits per year. An adult tree 5-6 years old can yield from 45 to 110 kg, under ideal conditions, the yield of an adult tree aged 7-12 years reaches 115-160 kg per year.

Consider the harvest carefully ...

Fruits are oval in shape from 5 to 15 cm in length with a diameter of 5-6 cm and a rib depth of about 2 cm. The average weight of the fruit is 70-130 g. Usually, five longitudinal ridges form a "star" structure of cross sections, but the number of ridges forming rays stars, sometimes it can vary from 4 to 8.

Carambola fruit. Photo: Rita Brillliantova

The fruit is covered with a thin, translucent, smooth skin with a waxy coating, which, when ripe, acquires a color from pale yellow to dark yellow.

All carambola fruits contain a large amount of oxalic acid, while the varieties are divided into two categories - sour and sweet - although even the sweetest of them never exceed 4% sugar. The fruit reaches its maximum sweetness if it ripens on a branch.

The color of ripe fruits ranges from yellow to orange and beige. A thin waxed membrane covers the fruit with a delicate pulp. Fruit color is one of the characteristics of the variety. The pulp of the fruit is juicy, crunchy with a possible taste of apples, cucumbers, plums, grapes, gooseberries and needles. Each variety has its own flavor, accentuating one or another note or their combination.

The fruits do not require additional processing before eating. In mature fruits, before serving, the ends and dried ridges of the ridges are cut off.

Varieties differ in size and color of fruits, degree of waxing, taste, type of pollination, plant resistance to unfavorable conditions. The most famous varieties of the sweet category: Arkin (Florida), Dah Pon (Taiwan), Fwang Tung (Thailand), Maha (Malaysia), Demak (Indonesia), sour category: Golden Star, Newcomb, Star King, Thayer (all - Florida) ... Golden Star can ripen to sweetness on the tree. The sweet Arkin, named for its creator, is now the most common cultivar in the United States, accounting for 98% of Florida's plantings.

Carambola fruits are a low-calorie product (31 kcal / 100 g), but they should be used with caution by people with problems of the gastrointestinal tract and kidneys, because a high concentration of acids can significantly worsen the condition. It is not recommended for patients with urolithiasis due to the high content of oxalates. In addition, carambola, like grapefruit, actively interacts with drugs, increases their absorption, thus increasing the risk of intoxication.

In addition to a large amount of vitamin C (34.4 mg), which is 57% of the body's daily allowance, 100 g of carambola contains -1 g of proteins, 0.3 g of fat, 6.7 g of carbohydrates, 3 mg of calcium, phosphorus - 12 mg, iron - 0.08 mg, potassium - 133 mg. The fruits also contain a whole complex of vitamins: C, A - 66 mg, B1 - 0.014 mg, B2 - 0.016 mg, B3 - 0.367 mg, B5 - 0.391 mg, B6 - 0.017 mg, B9 - 12.0 mg, E - 0 , 15 mg (quoted from USDA National Nutrient Database for Standard Reference, Release 18 (2005).

Before acclimatization, carambola was grown as an ornamental plant. Beautifully formed crown pruning, abundant and long flowering, fruits of an unusual shape - all this has long attracted the attention of landscape designers. Technologies for growing carambola at home have now been developed.

Propagation of carambola

Carambola is propagated by seeds and grafting. The fruit contains up to 10-12 light brown seeds, about 1 cm (0.7-1.2 cm) in size, flattened in length and similar in shape to melon seeds. Each seed is located in a gelatinous cell in the flesh of the fruit's body, near the central axis. Seeds for planting are taken from fresh ripe fruits that have ripened on the tree. You cannot store seeds, because within several days they lose their germination.

After 2-3 weeks (sometimes after 8 weeks) shoots appear after planting. Seedlings with a height of 6-8 cm tolerate transplanting well. Plants grown from seed may lose their characteristics. Therefore, propagation by grafting is more common, which guarantees the preservation of the properties of the mother plant. In addition, grafted trees have a more compact crown.

Carambola at home

The fruits of the potted plant. Photo: Vladimir Sheiko

In indoor conditions, grafted dwarf forms are grown, for example, the Maher Dwarf variety. It begins to bear fruit, reaching a height of 45-60 cm. The main conditions for fruiting are bright lighting, temperature not lower than + 20 + 25 ° C, moisture in the soil and in the air.

But the plant feels much better in humid tropical greenhouses, where it blooms profusely and bears fruit.

Cm. Carambola

Carambola in cooking

Carambola has found application in both cooking and folk medicine. Most often, star-shaped fruit slices are used to decorate dishes, desserts and cocktails. Green fruits are used as vegetables, they are added to hot dishes, salads, salted and pickled.

Juice, jam are made from fruits, added to drinks and sauces. In hot countries, sour carambola varieties are valued as more refreshing, while in temperate climates, sweet varieties are preferred.Sour and unripe fruits are often used as vegetables and added to dishes, which at the same time acquire a peculiar taste and aroma. In some countries the fruits are dried, in China and Taiwan they are canned in syrup.

In India, carambola is included in many spices. Due to its sour taste, it goes well with fish and meat dishes. In China, lightly fried pieces of fruit are used as a side dish. In Thailand, carambola is served with shrimp, and in Jamaica, the fruit is dried.

Sour carambola juice can remove stains from clothes, and the fruit pulp can be used for polishing copper and brass.

Carambola recipes:

  • Grilled salad with carambola, mango and romaine lettuce
  • Fruit salad with carambola
  • Salad with carambola, feta and avocado
  • Flip Pie with Starfruit
  • Baked fish fillet with carambola and vegetables
  • Sweet omelet with bananas and carambola
  • Curd cake "Tropicana Exotic"

Medicinal properties of carambola

In addition to its use in cooking, carambola has medicinal properties. The fruits are rich in antioxidants - polyphenolic flavonoids, including quercitin, epicatechin and gallic acid. The total content of flavonoids is 143 mg / 100 g. Flavonoids contribute to the oxidation of free radicals in the body and their elimination. In addition, the weak antimicrobial activity of the carambola fruit was confirmed.

In India, the fruit is used as a hemostatic agent. Brazilians use the crushed leaves to treat ringworm and chickenpox, and apply the leaves to the head for headaches. Seed powder lowers blood pressure, relieves colic and coughing attacks, up to asthmatic. Carambola juice relieves hangovers more effectively than any pickle. The roots, ground with sugar, are taken as an antidote for poisoning.

Such a delicate and complex fruit does not tolerate transportation well and has a short shelf life. Therefore, in industrial cultivation, the fruits are not completely ripe, but when the body of the fruit, connecting the ribs, turns yellow, and the ribs themselves still remain light green. The removed fruit can be stored in the refrigerator for up to 3 weeks. Fruits, left at room temperature, ripen rapidly without adding sugar content, and are stored for no more than 3-5 days.

Ripe fruits are stored for 2-3 days at room temperature. If the purchased carambola fruits tasted sour to you, you can add them to fish and meat dishes.