Ultimate French delicacy

French black truffles are getting scarcer all the time. By one estimate, the crop has declined from about 1,000 tonnes per year at the beginning of the 20th century to about 20 tonnes in the last decade of the same, opines Shirish Joshi

THE truffle is a mushroom from France. Called the "Black Diamond of Gastronomy," this truffle of southern France has been valued for centuries as the ultimate French delicacy. It is not a mere fungus or common mushroom. The French black truffle is rare and literally worth its weight in gold. The prices are more than £ 300 a kg in England. In the USA the price is $ 1,500 a kg. Truffles are harvested in early November.

Because it is pungent and aromatic, it is used in small amounts only. It is most often sprinkled as black specks in some French delicacies and omeletts. The black truffles grow unpredictably and can not be cultivated or even seeded in specially planted oak groves.

French black truffles are getting scarcer all the time. By one estimate, the crop has declined from about 1,000 tonnes per year at the beginning of the 20th century to about 20 tonnes in the last decade of the same. The explanation is that wars, fire and housing colonies have destroyed the oak tree forests that the truffles require. Even air pollution due to automobile exhaust and other industrial gases have affected the output of the truffles.

However, it has recently been found possible to promote artificial production of truffles by planting truffle-oaks which carry with them the spores of truffles, amid oak or hazelnut plantations, a mycelium obtained from a mash of truffles in water which has been spread upon the green leaves of these trees.

There are about 30 different varieties of truffles in the whole world. Italian truffles are white English ones are black or brown. The best truffles in France grow in the forests around Perigord, in France. The truffles from Perigord are black with white veins. They are intensely flavoured.

Italian truffles are white. The best Italian truffles grow in Italy’s Abruzzo region. They are sold for $ 4,000 a kg in the USA. Italians call it ‘Back Gold’. A dinner consisting of delicacies flavoured with white truffles costs around $ 80 per head.

The truffle is a tuber like mushroom that grows completely 7 to 30 cm underground. It receives nourishment from the roots of trees, primarily the oak trees which are common in Europe. But wherever the truffles grow, everything above dies.

Truffles are called Guchchhi in India. They grow in Kashmir, Himachal Pradesh, Tehri Garhwal, Kumaon, Sikkim, Darjeeling and Arunachal Pradesh, mainly as a forest product. Farmers in India, who harvest this wild produce, have individual methods to locate a truffle. Indian truffles are sold for Rs 300 per kg.

The harvesting of truffles is a tricky business. An unusual phenomenon was observed by ancient people from Babylon for the first time that wild pigs were digging for this fungi that grows underground in early winter months. Even today the fungi is harvested by using dogs or pigs which are especially trained to sniff out the distinctive aroma.

In the Perigord region farmers use female pigs as searchers for truffles. It is a pig’s job to sniff out this buried treasure. Pigs can detect a truffle 25 cm deep from a distance of about 6 metres. While pigs have a keener sense of smell, they eat the truffles. Their mouths are covered with nets, so that they do not eat them.

Dogs’ sense of smell is not so keen but they do not gobble them up. Dogs are easier to carry in the back seat of a car than pigs. Mushroom collectors then dig out the truffles. Such truffle-hunting dogs have to be guarded carefully as other truffle hunters are likely to steal them. But the method has its own problems, like the short attention time of animals and erratic search pattern. This results in the loss of about 20 per cent of the crop.

Earlier it was believed that truffles had some powers to encourage love making. A chemical analysis has shown that truffles contain some steroids which are similar to hormones produced by human beings through the organs of their reproductive system.

Scientists working at the University of Manchesters Institute of Science and Technology in collaboration with French scientists have developed an electronic nose to detect truffles. The gadget relies on the distinct odour of truffles. The device has two dozen sensors containing semi-conducting polymers.

The electrical resistance of these polymers changes when they come into contact with air-borne chemicals that constitute the odour of truffles. Signals from the sensors are processed by a computer, programmed to recognise the unique odour of truffles.