Truffles are a relatively rare species of an underground mushroom that grows in the roots of some trees or bushes. Truffle is the generic name of all the underground fleshy mushrooms-fungi belonging to the family Tuberaceae and to the genera Tuber  and Terfezia. Their size is appoximately 2-7cm, their colour varies from greyblack to whiteochre and they grow underground in a depth of 6-15 cm. Like all fungi they cannot compose the necessary substances to survive. In order to compensate this impossibility, they attach to some plants (trees or bushes), creating a relationship called “mycorrhizal symbiosis”, from which beneficiate both parties.  The symbiosis takes place in ligneous and forage plants and mainly in some forest species like hornbeams, hazels, pines,  poplars,  oaks, willows and limetrees.

Truffles are known since ancient times. Many writers describe the interest that mankind has always shown for these fungi. Athenaeus dedicates an entire chapter to the truffles but other writers like Galenus, Dioscourides, Theophrastus, Plutarch, Pliny and Cicero mention this mushrooms in their works. Theophrastus says that truffles growing in Lesvos, Samos, Ileia and Thrace are known with different names. The first written report about truffles takes place during the 4th century B.C. During the classical period, Plutarch, Cicero and Dioscourides, trying to explain the strange presence of truffles on the roots of the trees, they thought they were the result of thunders reaching the earth. Anyhow, the truffles of ancients Greeks have no relation with the actual botanical species of the mushroom Hydnum of the Hydnaceae family, because the “hudnae” of our ancestors belong, as we previously said, to the genera Tuber and Terfezia of the Tuberaceae family, the exquisite mushrooms reknown worldwide for their tastyfulness and their fine aroma. This is the reason why many writers and poets praised them in their works. Plinius, for instance, condidered truflles as “nature’s miracles”. Porfyrius used to call them ‘’children of the Gods” , Cicero ‘’daughters of the earth’’ and Nero ‘’food of the Gods’’. Apicius and Juvenalis were celebrating the virtues of truffles and invented various culinary uses. Alexandre Dumas characterised them as ‘’the holiest ingredients of the table” and the French used to call them ”the black diamonds of the kitchen”. In Greece, truffles have always been highly praised as the old popular saying from the Pelopenese confirms: “Undigable, unplantable... and noble cooking”.

Truffles like all the other mushrooms do not have blastic organs (roots, seeds and buds). Dioscourides and Theofrastus, as botanologists provided a brief and accurate desciption of truffles:‘’...They are round roots with no leaves, no bud, they have blondish colour and they can be found in spring time, they are eatable either raw or cooked”. Theophrastus says: “… truffles have no bud, no branch, no leaf, no flower, no fruit, no peel, no wooden part, no fibres, and no vessels’’. Their origin remained a mystery for a long time and the botanologists worked hard in order to determine the real nature of these mushrooms. The apparent absence of a reproductive organ was the main obstacle in order to explain they way they reproduced and it was initially believed that they grow randomly in the soil. Because generally mushroom seeds, unlike the seeds of other plants, are tiny and cannot be spotted by a naked eye, their existence was invisible before the invention of the microscope. And also, because truffles have their own particular way of life. So, Athenaeus was right to say that they were automatically created: ‘’ Truflles grow alone (without seeds) in sandy places”. And Plutarch in “ the “Symposium” speaks arinically about the idea of their automatic birth and the theory that they were created by thunders. Of course, truffles, like the rest of the myshrooms, multiply by seeds that are created in specific reproductory organs and that spread in the soil thanks to natural factors like the air and the water. We are astonished even today from the intelligence of the ancient Greeks, who, despite the limited scientific knowldge of their time, they accurately observed that truffles are originated from seeds, as it results form the following relevant passage written by Theophrastus: “Some people believe that their origin is from seeds. For istance, in the coastline of Lesvos there were no truffles before the heavy rains brought the seed for the land of Tiares, a region were truffles grow abundandly because truffles grow in regions where there is sand.”

It is estimated that there is about a hundred truffle species. Even though many among them are similar to the reknown truflles, they are not all eatable and harmless but none of them is leathal. They all have white flesh, various tints, depending on the trees on the roots of which they grow. We can distinguish them macroscopically by their colour (white, blondish or black) and the morphology of their skin ( smooth or hard. Also, depending on the season during which they grow, they can be classified as winter or summer truffles. From a commercial point of view, they are classified as white or black, and the latter are the most reputated ones.

Pliny writes about the different categories of truffles: ‘’There are two kinds of truffles, one full of sand that hurts the teeth and the other, which is sandless and totally clean. They can be distinguished by their colour- redish, white or black -and the most reputated ones come from Africa”. In Greece and Cyprus the most common and reknown truffles, up to today, are the following: Tuber melanosporum,  Tuber aestivum , Tuber cibarium , Tuber magnatum , Terfezia leonis , Terfezia leonis var. Majus, Terfezia Genadii , Terfezia leonis var.minor , Terfezia Fanfani , Terfezia Claveryi , Terfezia Aphroditis. Truffles grow in a depth of 10-30 cm and their size varies from the size of a corn to that of a potato. Even though truffles weighting over a kilo have been found, the average weight is approximately 20-40 gr. Plutarch reports that he had dinner in the region of Hleia, eating huge truffles. They are rich in protein mushrooms and that is why they are considered as “vegetal meat” with a delicious and aromatic flesh. They can be eaten raw, cooked or conservated in a can with oil, vinagre, salt or dried. Dioscourides writes that truffles are collected during spring time and that they can be eaten cooked or raw. In some passages of Theophrastus, that have been rescued by Athenaeus in “Deipnosophists”, he reports that they are tastfull and they smell like meat and that they “become hard during the automn rains and mainly by the thunders which are probably the reason that makes them hard”. In the same work, Difullus characterizes truffles difficult to digest but at the same time delicious. Truffles have been always recommended as an aphrodisiac. In some places in the Tchech Republic, the popular name of truffles is “ lamp’s fries’’. Some other species of elaphomyces, another truffle variety, used to be sold in Europe in the past as aphrodiasiac by the herb merchands who beleived that it was growing in regions were the deers were fornicating. Simon Sith indicates the way truffles were cooked: ‘’Truffles should be washed well with clear water, salt and oreganon, and after been baked they should be eaten with oil and pepper.

As truffles don’t have above-ground organs, it is very difficult to find them in nature and the majority of times this happens randomly. In order to determine the locations where they grow, different indications are used as for example, the specific trees of the region, the total lack of grass, swarms of yellow flies flying in low altitud over the truffle areas, the light elevation of the soill and the clefts of the ground under which this mushroom grows. But the most remarkable of all is that when truffles mature, they emanate an intense smell that can be detected from a long distance by some animals like pigs, squirrels, deers, dogs and bears. This is the reason why, from the ealry years up to today, trained dogs or pigs are used for truffle hunting. The reputation of truffles as a savoury food and its great demand have always been provoking an increasing interest for cultivation. Pythagora and Galenus 2500 years ago strongly believed that they can be artificially cultivated. But domesticating truffles is a very hard task. Beacuse they are heterotroph organisms and they have a particular way of coexistencing with other plants . It has been noticed that truffles grow in the roots of approximately 50 kinds of trees like oaks (Quercus sp.), poplars (Populus sp.), lindens (Tilla sp.), willows (Salix sp.), hazels (Corylus sp.), chestnuts (Castanea sp.) etc. They increase the absorbing surface of the roots from where they recieve the necessary substances in order to survive. Thus, both of the collaborating parties benefit. So, Pliny was right when he was wondering “how a truffle can grow and live without roots”. For the Romans, truffles were a familiar food . They were importing white Terfezia truflles that grow in the desert from Libya in sealed recipients filled up with sand. Gauls considered truffles as an excellent food. The oak was a sacred tree and the truffles growing on its “feet” were considered as a gift from the skies. 

Somewhat surprisingly, truffles have a very high protein content, which is why they are often described as 'vegetable meat'. White and black truffles have the same chemical content and are made up of 73% water, the remaining weight comprising several types of minerals and organic substances such as calcium, potassium and magnesium. There have been a number of studies made to find out why pigs simply go 'mad' for the tuber and why it was mainly the sows (female pigs). At one point it was understood that they were detecting an androstenol (5 -androst-16-en-3 -ol), a steroid alcohol which has been identified in truffles and is also in a boars' saliva. It was a French chemist called Thierry Talou who conducted an experiment hiding samples of fresh truffles, androstenol (5alpha -androst-16-en-3alpha -ol) and some synthetic truffle aroma without the 5alpha -androst-16-en-3alpha -ol. The conclusion was that the pigs ignored the androstenol (5alpha -androst-16-en-3alpha -ol) but showed interest in the real truffles.

The fresh truffles contain a number of organic molecules known as alcohols, aldehydes and ketones. The smell of the truffle is actually due to a molecule known as dimethylsulphide or CH3SCH3 (which is also found in asparagus) along with a collection of others. These molecules are also known as 'volatiles'. Amongst the main varieties of truffles, the relative quantities of alcohols to aldehydes to ketones varies, but they all contain dimethylsulphide molecules.

 

More than 200 volatile organic compounds have been to date described from various truffle species. A single species typically contains between 20-50 volatiles, and the composition of these volatiles might depend on geographical location and/or maturity.
When the truffles are kept over a period of time the volatile sulphur compounds escape faster than the other molecules. It is the release of the dimethylsulphide (CH3SCH3) molecules along with CH3CH2CH2SCH3 and CH3CH=CHSCH3 into the air that give the truffles that strong pungent smell.

Reviews on the available data on chemical composition and nutritional quality: moisture (75.21-79.38 %), protein (19.59-27.18 %), fat 92.81-7.42 %), crude fiber (7.81-14.89 %), ash (4.33-6.39 %), and ascorbic acid (0.70-5.10 mg/100 g). It also contains high amounts of K, P, and fair levels of Ca, Mg, Na, Fe, Cu, Zn, and Mn. Reports show that truffle contains all essential amino acids.

Fungi are an important source of primary and secondary metabolites and have for long been exploited by the pharmaceutical and food industries. A large number of these metabolites can thus be described in terms of their usefulness to our human society (i.e. benzaldehyde, a volatile with a typical almond odor, is the most exploited aroma of the food industry, or citric acid. 

"...It is generally believed that the truffle excites the genetic sense." So wrote Jean Antheleme Brillet-Savarin, the renowned 17th century gastronome, in his classic work The Physiology of Taste.

A great deal has been written before and since regarding the aphrodisiacal property of the truffle, and while no hard scientific evidence has yet turned up to support any chemical substance as being a reliable trigger of sexual desire in humans, there is some evidence that some species of truffles produce a pheromonal scent that is a mating trigger in female pigs. "Human interest in truffles may also owe something to this hormone. The rich, almost meaty flavor of the fungi and their ability to intensify the flavor of vegetable dishes are largely due to an abnormally high content of glutamic acid, which makes them a natural version of monosodium glutamate. Mushrooms respire very actively after harvest compared to most produce, and during four days' storage will lose about half of their sugar and starch reserves to chitin."

Do truffles actually have aphrodisiacal properties?
The answer is a qualified yes.

But then again, a fine dinner by candlelight, the sweet shaving of white truffles over a perfectly creamy risotto, a tender, blood-rare filet wrapped with wild boar bacon and drenched in black truffle cream, a glass of magnificent Bordeaux, and surely the atmosphere of romance might well accomplish what the chemical alone cannot. Even if the truffle has no aphrodisiacal properties in and of itself, it is still a dish for lovers.