Nature Diary
Tamarind

Who hasn't seen tamarind fruit hanging in bunches from road-side trees? Or hasn't seen children throwing stones, trying to bring the fruit down so that they can eat them?! Tamarind trees are so common in India that most people think it is native to India. But it originated in tropical Africa, including Sudan and parts of the dry deciduous forests of Madagascar. It was introduced into India so long ago that people mistakenly think it is indigenous here. In fact, the name was given by the Persians and the Arabs when the fruit reached them from India. They called it "Tamar-u'l-Hind" which means Indian date. They chose this name because of the brown date-like appearance of the dried pulp of the tamarind. The official name is Tamarindus Indicus. It is thought that the Swede Carl Linnaeus gave the specific epithet Indicus because of this name although the fruit was well known to both the ancient Egyptians and to the Greeks in the 4th Century B.C.
The tamarind is a slow-growing, long-lived, massive tree. In some parts of the world, the seedlings begin to bear fruit in the 4th or 5th year, but in India, it may take more than 10 years before it bears fruit. The tree bears abundantly up to an age of 50 years or sometimes longer, though it may live another 150 years.
The tree can reach a height of 24-30 m with a huge trunk of 3 m diameter. It is highly wind-resistant, with strong, supple branches, gracefully drooping at the ends, and has a dark-gray, rough, fissured bark. That is why it is commonly seen as a road-side tree or as the preferred "conversation" tree in villages, although it is extensively grown in orchards as well.
The branches droop from a single, central trunk. The mass of bright-green, fine, foliage is composed of leaves, each having 10 to 20 pairs of oblong leaflets which fold at night. Such leaves are called pinnate and are clearly identified by their feathery appearance. The leaves are normally evergreen but may be shed briefly in very dry areas during the hot season.
The tree flowers in summer but the flowers are small and difficult to see. Just about an inch wide, they are borne as a bunch together on a short stalk. They have 5 petals, not all of the same size, and are yellow with orange or red streaks. A more beautiful sight are the flowerbuds that are pink due to the outer color of the 4 sepals which are shed when the flower opens. The flowers are a good source of nectar for honeybees in South India. The honey is golden-yellow and slightly acidic in flavour.
However, although the leaves can also be eaten, this tree is not famous for its leaves or flowers, but of course, for its fruit! The fruit are most commonly seen in South India. In northwestern India, the tree grows well but the fruits do not ripen. Dry weather is important during the period of fruit development.
The fruits are flattish and beanlike, with irregularly curved and bulged pods. They are borne in great abundance along the new branches and usually vary from 5 to 20 cm in length. Exceptionally large tamarinds have been found on individual trees. The pods may be cinnamon-brown or grayish-brown externally and, at first, are tender-skinned with green, highly acid flesh and soft, whitish, under-developed seeds. This is when they are the most coveted by children! As they mature, the pods fill out somewhat and the juicy, acidulous pulp turns brown or reddish-brown. Thereafter, the skin becomes a brittle, easily-cracked shell and the pulp dehydrates naturally to a sticky paste enclosed by a few coarse strands of fiber extending lengthwise from the stalk.
The fruits begin to dehydrate in 7-8 months, losing approximately half of their moisture content up to the stage of full ripeness. The ripe fruit are usually picked in January or February, sometimes as late as April. Harvesters merely shake the branches to cause mature fruits to fall and they leave the remainder to fall naturally when ripe. The pulp is rich in calcium, phosphorus, iron, and Vitamin B.
Each fruit has a few hard, glossy-brown, squarish seeds, enclosed in a parchmentlike membrane. Tamarind seeds remain viable for months and will germinate in a week after planting.
The tamarind is widely used in cooking, to make food sour. Not just sambhar, but many kinds of rice, fish and meat are cooked in tamarind paste. But it also has commercial uses.
In 1942, Indian scientists found that the kernels contained large amounts of a gel-forming substance. The purified product, called "Jellose", "polyose", or "pectin", has been found superior to fruit pectin in the manufacture of jellies, jams, and marmalades. It is recommended as a stabilizer in ice cream, mayonnaise and cheese and as an ingredient in a number of pharmaceutical products.
Tamarind leaves and flowers are useful as mordants in dyeing. They also have medicinal uses.
The powder made from tamarind kernels (seeds) has been adopted by the Indian textile industry as 300% more efficient and more economical than cornstarch for sizing and finishing cotton, jute and spun viscose, as well as having other technical advantages.
-Compiled from various sources