Black Truffle Mushroom

Common names

• Black Truffle Mushroom
• French Black Truffle
• Perigord Truffle

Black truffles (scientific name Tuber melanosporum) are some of the rarest and most expensive mushroom varieties in the world. The species is native to the forests of Southern Europe and is a member of the fungi family Tuberaceae and the Tuber genus. Truffles are actually the underground fruiting bodies of the species, which have a round shape. There are numerous varieties in size and color, usually they are black but the color can also be brown, yellow or white. Their skin can be smooth or covered by small warts. The species has a very unusual propagation method, since it relies on spores released from flasks, even if they are located underground where this cannot work. In reality, they rely on animals that dig and consume the fruiting bodies. The spores are specially built for this purpose and remain viable even after they pass through the entire digestive system of an animal. After excretion, they will try to link with the root system of a compatible tree and start a fully functional new mycelium. This strange propagation cycle explains the unique taste and aroma of truffles. While humans can usually only detect the smell if a fruiting body is sliced, animals like pigs or dogs have much stronger senses and can smell truffles located deep underground. As a result, people who gather truffles employ dogs or pigs in order to find them. Both the famous black truffle (Tuber melanosporum) and the Italian Piedmont truffle (Tuber magnatum) have developed a scent that resembles sex hormones of male pigs. Female pigs are naturally attracted to them without any additional training, so they have been used by professional truffle hunters for a very long time. Today, trained dogs are usually preferred for this task. Even if truffles are fungi, their life is very different from other species. Their fruiting bodies grow underground at various depths; some are shallow while others can be located very deep. They have a rounded shape, sometimes lobed, and the color ranges from yellow to black. The flesh can be marble white or even fully black, several narrow veins start from the base in a radial pattern. At maturity, truffles develop a very strong and complex smell. Truffles can be found in the wild, in densely forested areas of the Northern Hemisphere. They are famously present in France and Italy but are also numerous in other areas, such as the Balkans. Tuber melanosporum, also known under alternative names French black truffle or black perigord truffle, is native to Southern Europe. It is easily identified due to the black flesh with small white veins. Black truffles have a special aroma that makes them a delicacy in gourmet cuisine and the most expensive truffle variety. However, other black truffles also exist. Some of the most common and popular in world cuisines are the black summer truffle (T. aestivum) and the Burgundy truffle (T. uncinatum). Tuber magnatum, popularly known as the white truffle, is native to Northern Italy and the largest species in size. The taste resembles a mix of cheese, garlic and mould, being very a highly rated cooking ingredient. Several species are native to the North American continent. T. gibbosum, or the Oregon black truffle, is also a very expensive variety found in the US state with the same name. Pecan tree plantations in the Southern USA are home to Tuber lyoni, or the pecan truffle.

Uses

Black truffles are a famous gourmet food but scientists have recently started to investigate their medicinal properties as well. Some of the effects that could be used by the pharmaceutical industry are the boost of the immune and cardiovascular systems, decrease of high cholesterol levels, better sexual health, treatment of cancer and aging management. Black truffles can also cure food intolerance, pain caused by rheumatism and sleep issues. They are considered an anti-aging super food due to the rich content of antioxidants. The strong and unique taste of black truffles can transform any dish into a delicacy. It should be added at the end, after the cooking is complete, only a very small amount is required. It pairs well with any recipe but is usually added to pastas, poultry, beef or rice. It can also be an aromatic ingredient in vinegar or olive oil. A number of volatile organic compounds (VOC's) have been identified as the reason for the unique flavour of black truffles. Scientists have isolated several aromatic hydrocarbons, sulphur compounds, terpenes and phenols. They also include a generous amount of quality natural proteins, that are digested easily. In traditional societies, truffles were considered to be an effective aphrodisiac. Black truffle mushrooms have been considered a special expensive food since ancient times. Any dish that includes truffles today will mention this fact due to their gourmet reputation. They are one of the ingredients that have remained popular throughout history. Truffles superficially resemble small potatoes in shape and size. Black truffles are immuno-modulators and can make the immune function adapt to external threats and increase its reaction to the needed level. A weak immune system is boosted, while one that is too active becomes balanced, avoiding for example autoimmune diseases. In addition, black truffles are potent killers of bacteria and their content of antioxidants makes them useful in the treatment of cancer. Truffle oil has an exquisite aroma but the real product is extremely expensive. However, chemists have found an ester compound that smells almost like real truffles and can be produced synthetically, in order to create affordable oil. Commercially available truffle oil usually consist of a quality base product, the most common being extra virgin olive oil. Both white and black truffles can be added to it, changing the color of the oil to light or dark. Real truffle oil, produced only from truffles, has a powerful aroma and an average content of fatty acids. It is a strong antiseptic and antioxidant oil. However, oil produced solely from these mushrooms is extremely expensive and almost impossible to find.

Habitat and cultivation

Black truffles have a natural habitat that covers areas of France, Italy and Spain. Scientists suspect that during the last Ice Age, the trees that have a symbiotic relation with truffles retreated to these areas. The mushrooms have always been present there but the real tradition of harvesting has started about 200 years ago. Truffles must be gathered manually, using old methods, and their habitat is in very large natural forests. Pristine forests are still found in many areas of Europe, for example in the Spanish province of Castell�n, especially the Alto Maestrazgo county, where truffles have ideal growth conditions. Some of the local villages are famous for truffles, for example Alboc�sser, Atzaneta, Morella or Culla. However, pollution and climate changes are increasingly threatening these traditional areas. After 2010, a serious productivity drop of truffles found in natural forests has been detected. This is being compensated by cultivation. In Spain, the main cultivation area is in Aragon in the Soria, Teruel province. Several thousand hectares of central Spain are now dedicated to truffle cultivation. Areas with burnt forests seem to be a great development option, since these already have the legal status of forest land and no additional permits are required to plant new trees and truffles there. Black truffles are now being cultivated in other countries in the world, far away from their native range. They are harvested in Wales or North America but also in Australia, New Zealand, Chile and South Africa. One of the methods used is to plant hazel trees already inoculated with truffle mycelium in their roots. However, up to ten years are needed until the first fruiting bodies can be harvested. As underground mushrooms, black truffles can't be detected by people who walk in the woods. They can be located anywhere in forests, there are no clear patterns and the exact place must be discovered using trained animals. The demand for truffles will always be much greater than the supply, so they are extremely expensive.

Collection and harvesting

Wild truffles have a symbiotic relation with trees such as oaks, poplars, pecans, beech, hazelnuts and elms. As part of their propagation method, truffles attract wild animals at maturity by producing strong odors and volatile organic compounds that resemble pheromones. During the autumn and winter, truffle harvesters use trained dogs to find them in the forests. Raking is another method to dig up truffles and locate them underground. While effective, this method is risky because it can cut the truffles and the damage significantly reduces their value. A second problem is that raking severs the link between unripe truffles and trees, so they will never reach maturity.