Truffle

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For other uses, see Truffle (disambiguation).
Black Périgord truffle

A truffle is the fruiting body of a subterranean Ascomycete fungus, predominantly one of the many species of the genus Tuber. Truffles are ectomycorrhizal fungi and are therefore usually found in close association with the roots of trees. Spore dispersal is accomplished through fungivores, animals that eat fungi.[citation needed]

Some of the truffle species are highly prized as food. French gourmet Jean Anthelme Brillat-Savarin called truffles "the diamond of the kitchen".[1] Edible truffles are held in high esteem in Croatian, French, Georgian, Greek, Italian, Middle Eastern, and Spanish cooking, as well as in international haute cuisine.

History[edit]

Antiquity[edit]

The first mention of truffles appears in the inscriptions of the neo-Sumerians regarding their Amorite enemy's eating habits (Third Dynasty of Ur, 20th century BCE)[2] and later in writings of Theophrastus in the fourth century BCE. In classical times, their origins were a mystery that challenged many; Plutarch and others thought them to be the result of lightning, warmth and water in the soil, while Juvenal thought thunder and rain to be instrumental in their origin. Cicero deemed them children of the earth, while Dioscorides thought they were tuberous roots.[3]

Italy in the Classical period produced three kinds of truffles: the Tuber melanosporum, the Tuber magnificanus and the Tuber magnatum. The Romans, however, only used the terfez (Terfezia bouderi), a fungus of similar appearance, which the Romans called truffles, and which is sometimes called "desert truffle". Terfez used in Rome came from Lesbos, Carthage, and especially Libya, where the coastal climate was less dry in ancient times.[3] Their substance is pale, tinged with rose. Unlike truffles, terfez have no taste of their own. The Romans used the terfez as a carrier of flavour, because the terfez have the property to absorb surrounding flavours. Indeed, Ancient Roman cuisine used many spices and flavours, and terfez were perfect in that context.

Middle Ages[edit]

Truffles were rarely used during the Middle Ages. Truffle hunting is mentioned by Bartolomeo Platina, the papal historian, in 1481, when he recorded that the sows of Notza were without equal in hunting truffles, but they should be muzzled to prevent them from eating the prize.[4]

According to a hadith narrated by Saeed bin Zaid, Muhammad said that truffles are like manna and that water from truffles "heals eye diseases".[5]

Renaissance and modern times[edit]

During the Renaissance, truffles regained popularity in Europe and were honoured at the court of King Francis I of France. However, it was not until the 17th century that Western (and in particular French) cuisine abandoned "heavy" oriental spices, and rediscovered the natural flavour of foodstuffs. Truffles were very popular in Parisian markets in the 1780s. They were imported seasonally from truffle grounds, where peasants had long enjoyed their secret. Brillat-Savarin (1825) noted characteristically that they were so expensive they appeared only at the dinner tables of great nobles and kept women. A great delicacy was a truffled turkey.

Cultivation[edit]

Mushroom and truffle output in 2005
Planted truffle groves near Beaumont-du-Ventoux

Truffles long eluded techniques of domestication, as Jean-Anthelme Brillat-Savarin (1825) noted:

The most learned men have sought to ascertain the secret, and fancied they discovered the seed. Their promises, however, were vain, and no planting was ever followed by a harvest. This perhaps is all right, for as one of the great values of truffles is their dearness, perhaps they would be less highly esteemed if they were cheaper.[1]

However, truffles can be cultivated.[6] As early as 1808, there were successful attempts to cultivate truffles, known in French as trufficulture. People had long observed that truffles were growing among the roots of certain trees, and in 1808, Joseph Talon, from Apt (département of Vaucluse) in southern France, had the idea of transplanting some seedlings that he'd collected at the foot of oak trees known to host truffles in their root system.

For discovering how to cultivate truffles, some sources now give priority to Pierre II Mauléon (1744–1831) of Loudun (in the Vienne department), who began to cultivate truffles ca. 1790. See: Thérèse Dereix de Laplane (2010) "Des truffes sauvages aux truffes cultivées en Loudunais" (From wild truffles to cultivated truffles in the area of Loudun), Mémoires de l’Académie des Sciences, Arts et Belles-Lettres de Touraine, 23 : 215–241. Available on-line at: Academy of Touraine From pp. 224–225: " … le paysan, a alors l'idée, vers 1790 — puisqu'il y a symbiose évidente entre le chêne, les galluches et la truffe — de provoquer la formation de truffières, en reproduisant leur environnement naturel par des semis de glands dans ses "terres galluches". Avec "les glands venus sur les chênes donnant les truffes, des semis furent faits dans les terrains calcaires voisins" … " ( … the farmer [viz, Pierre II Mauléon] then had the idea, around 1790 — because there is an obvious symbiosis between the oak tree, the rocky soil, and truffles — of inducing the formation of truffle patches, by reproducing their natural environment by sowing acorns in his rocky soils. With "the acorns [that] came from the oak trees producing truffles, sowings were made in the neighboring chalky plots" … ) See also: Léon de la Toubette (1869) "Culture de la truffe à Loudun et à Richelieu," Annales de la Société d'Agriculture Sciences, Arts, et Belles-lettres du Départment d'Indre-et-Loire, 10th series, 48 : 300–302 ; see p. 300.

Truffle market in Carpentras

The experiment was successful: Years later, truffles were found in the soil around the newly grown oak trees. In 1847, Auguste Rousseau of Carpentras (in Vaucluse) planted 7 hectares (17 acres) of oak trees (again from acorns found on the soil around truffle-producing oak trees), and he subsequently obtained large harvests of truffles. He received a prize at the 1855 World's Fair in Paris.[7]

These successful attempts were met with enthusiasm in southern France, which possessed the sweet limestone soils and dry, hot weather that truffles need to grow. In the late 19th century, an epidemic of phylloxera destroyed many of the vineyards in southern France. Another epidemic destroyed most of the silkworms there, too, making the fields of mulberry trees useless. Thus, large tracts of land were set free for the cultivation of truffles. Thousands of truffle-producing trees were planted, and production reached peaks of hundreds of tonnes at the end of the 19th century. In 1890, there were 75,000 hectares (190,000 acres) of truffle-producing trees.

In the 20th century, however, with the growing industrialization of France and the subsequent rural exodus, many of these truffle fields (champs truffiers or truffières) returned to wilderness. The First World War also dealt a serious blow to the French countryside, killing 20% or more of the male working force. As a consequence, newly acquired techniques of trufficulture were lost. Also, between the two world wars, the truffle groves planted in the 19th century stopped being productive. (The average life cycle of a truffle-producing tree is 30 years.) Consequently, after 1945, the production of truffles plummeted, and the prices have risen dramatically. In 1900, truffles were used by most people, and on many occasions. Today, they are a rare delicacy reserved for the rich, or used on very special occasions.

In the last 30 years, new attempts for mass production of truffles have been started. Eighty percent of the truffles now produced in France come from specially planted truffle groves. Nonetheless, production has yet to recover its 1900s peaks. Local farmers are sometimes opposed to a return of mass production, which would possibly decrease the price of truffles (though it is commonly stated that demand is 10 times higher than offer). In exchange there are heavy investments in cultivated plantations under way in many parts of the world. Thanks to controlled irrigation, regular and resilient production is indeed possible.[8][9] There are now truffle-growing areas in the United Kingdom, United States, Spain, Sweden, New Zealand, Australia, Chile and South Africa.

A critical phase of the cultivation is the quality control of the michorized plants. It takes indeed between 7 and 10 years for the truffles to develop their micchorizes network, and only after that the host-plants come into production. Both a complete soil analysis to avoid contamination by other dominant fungus and a very strict control of the michorization process are necessary to ensure the success of a plantation. Total investment per hectare for an irrigated and barrier-sealed plantation (against wild boars) can cost up to €10,000.[10] Regarding the level of initial investment and the maturity delay, farmers that have not taken care of both soil conditions and seedlings conditions are at high risk of failure.

In New Zealand and Australia[edit]

The first black truffles (Tuber melanosporum) to be produced in the Southern Hemisphere were harvested in Gisborne, New Zealand, in 1993.[11]

In 1999, the first Australian truffles were harvested in Tasmania,[12] the result of eight years of work. Trees were inoculated with the truffle fungus in the hope of creating a local truffle industry. Their success and the value of the resulting truffles has encouraged a small industry to develop. A Western Australian venture, The Wine and Truffle Company, had its first harvest in 2004, and in 2005 they unearthed a 1-kg (2.2-lb) truffle. In 2008, an estimated 600 kilograms (1,300 lb) of truffles were removed from the rich ground of Manjimup. Each year, The Wine and Truffle Company has expanded its production, moving into the colder regions of Victoria and New South Wales.

In June 2010, Tasmanian growers Michael and Gwynneth Williams harvested Australia's largest truffle from their property at Myrtle Bank, near Launceston. It weighed in at 1.084 kilograms (2 lb 6.2 oz).[13] Mrs. Williams told ABC Radio in Australia[14] that it is valued at about A$1,500 per kg.

New Zealand's first burgundy truffle was found in July 2012 at a Waipara truffle farm. It weighed 330 g, and was found by Rosie, the farm owner's beagle.[15]

Etymology[edit]

The origin of the word truffle appears to be the Latin term tūber, meaning "swelling" or "lump", which became tufer- and gave rise to the various European terms: Croatian tartuf / тартуф, Danish trøffel, Dutch truffel, English truffle, French truffe, German Trüffel, Italian tartufo, Polish trufla, Spanish trufa, Swedish and tryffel.

The German word Kartoffel ("potato") is derived from the Italian term for truffle because of superficial similarities.[16] In Portuguese, the words trufa and túbera are synonyms, the latter closer to the Latin term.

Biology[edit]

The mycelia of truffles form symbiotic, mycorrhizal relationships with the roots of several tree species including beech, birch, hazel, hornbeam, oak, pine, and poplar.[17][18] They prefer argillaceous or calcareous soils that are well drained and neutral or alkaline.[19][20][21] Truffles fruit throughout the year, depending on the species, and can be found buried between the leaf litter and the soil.

Phylogeny[edit]

The phylogeny and biogeography of truffles was investigated in 2008[22] using internal transcribed spacers (ITS) of nuclear DNA with five major clades (Aestivum, Excavatum, Rufum, Melanosporum and Puberulum); this was later improved and expanded in 2010 using large subunits (LSU) of mitochondrial DNA to nine major clades. The Magnatum and Macrosporum clades were distinguished as distinct from the Aestivum clade. The Gibbosum clade was resolved as distinct from all other clades, and the Spinoreticulatum clade was separated from the Rufum clade.[23]

Species[edit]

Black truffle[edit]

Main article: Black truffle
Black Périgord Truffle, cut

The black truffle or black Périgord truffle (Tuber melanosporum), the second-most commercially valuable species, is named after the Périgord region in France and grows with oak and hazelnut trees. Black truffles are harvested in late autumn and winter.[24] The genome sequence of the black truffle was published in March 2010.[25]

The following table shows the production in the EU of Tuber melanosporum in Spain, France and Italy. Production data is in metric tons, and country weights in percentage, and comes from the Groupe Européen Truffe et Trufficulture, an association of the main producers in Europe.

Years Spain France Italy EU  % of average year Spain vs EU France vs EU Italy vs EU
1990/1991 30 17 5 52 83 58 33 10
1991/1992 10 20 5 35 56 29 57 14
1992/1993 23 31 3 57 90 40 54 5
1993/1994 9 22 2 33 52 27 67 6
1994/1995 4 12 30 46 73 9 26 65
1995/1996 20 19 25 64 102 31 30 39
1996/1997 25 50 20 95 151 26 53 21
1997/1998 80 30 24 134 213 60 22 18
1998/1999 7 14 4 25 40 28 56 16
1999/2000 35 40 10 85 135 41 47 12
2000/2001 6 35 4 45 71 13 78 9
2001/2002 20 15 5 40 63 50 38 13
2002/2003 40 35 20 95 151 42 37 21
2003/2004 7 9 6 22 35 32 41 27
2004/2005 22 27 10 59 94 37 46 17
2005/2006 14 15 8 37 59 38 41 22
2006/2007 20 28 10 58 92 34 48 17
2007/2008 25 26 8 59 94 42 44 14
2008/2009 14 58 20 92 146 15 63 22
2009/2010 9 32 8 49 78 18 65 16
2010/2011 18 37,2 12 67,2 107 27 55 18
2011/2012 14,5 42,3 8 64,8 103 22 65 12
2012/2013 15 38,2 20 73,2 116 20 52 27
2013/2014 45 50 30 125 198 36 40 24

As the data shows, France has been the main producer of black truffles in the last century and a half, but is rapidly challenged by Spain, where regions have made use of the EU-funded Rural Development Programme (EARFD funding) to subsidise cultivated plantations. This is particularly visible in the Teruel province of the Aragón region where the black truffle represents the first and main economic activity (in GDP and employment). Especially since 2010-2011 when many plantations done under the last Rural Development Programme 2000-2006 came into production phase.

Summer or burgundy truffle[edit]

Main article: Summer truffle

The black summer truffle (Tuber aestivum) is found across Europe and is prized for its culinary value. Burgundy truffles (Tuber uncinatum) are harvested in autumn until December and have aromatic flesh of a darker colour.

Black summer truffle (in Italian: Tartufi Neri Estivi) in a shop window in Rome, Italy

White truffle[edit]

White truffle washed and cut

The "white truffle" or "trifola d'Alba Madonna" ("Truffle of the White Mother" in Italian) (Tuber magnatum) is found mainly in the Langhe and Montferrat areas[26] of the Piedmont region in northern Italy and, most famously, in the countryside around the cities of Alba and Asti;[27] Acqualagna, in the northern part of Le Marche near Urbino, is another renown center for the production and commercialization of white truffles and the annual festival is one of the most important in Italy.[28] White truffle can also be found in Molise, Abruzzo and in the hills around San Miniato, in Tuscany. It is also found on the Istria peninsula, in Croatia in the Motovun forest along the Mirna river,[29] and in Slovenia along the Dragonja and Rizana river,[30] as well as in the Drome area in France. Growing symbiotically with oak, hazel, poplar and beech and fruiting in autumn, they can reach 12 cm (5 in) diameter and 500 g, though are usually much smaller. The flesh is pale cream or brown with white marbling.[24] Italian white truffles are very highly esteemed (illustration, left) and are the most valuable on the market: The white truffle market in Alba is busiest in the months of October and November when the Fiera del Tartufo (truffle fair) takes place. In 2001, the Tuber magnatum truffles sold for between $1000–$2200 per pound ($2000–$4500 per kg);[31] as of December 2009 they were being sold at $14,203.50 per kilogram.

In 1999, Giancarlo Zigante and his dog Diana found one of the largest truffles in the world near Buje, Croatia. The truffle weighed 1.31 kilograms (2 lb 14 oz) and has entered the Guinness Book of Records.[32]

The record price paid for a single white truffle was set in December 2007, when Macau casino owner Stanley Ho paid $330,000 (£165,000) for a specimen weighing 1.5 kilograms (3.3 lb), discovered by Luciano Savini and his dog Rocco. One of the largest truffles found in decades, it was unearthed near Pisa, Italy, and sold at an auction held simultaneously in Macau, Hong Kong, and Florence.[33] This record was then matched on November 27, 2010 when Ho again paid $330,000 for a pair of white truffles, including one weighing nearly a kilogram.

In December 2014, a White Alba’s Truffle weighing in at 4.16 pounds or 1.89 kilos was unearthed in the Umbrian region of Italy by the Balestra Family of Sabatino. It was auctioned at Sotheby’s in New York.[34] While some had expected it to sell for $1 million,[35] it was sold for $61,000 to a Taiwanese buyer.[36]

A variety of white truffle (Tuber magnatum pico) is found in other parts of northern and central Italy, but is as aromatic as those from Piedmont.[24]

Whitish truffle[edit]

The "whitish truffle" (Tuber borchii) is a similar species found in Tuscany, Abruzzo, Romagna, Umbria, the Marche and Molise. It is not as aromatic as those from Piedmont, although those from Città di Castello come quite close.[24]

Other species[edit]

A less common truffle is "garlic truffle" (Tuber macrosporum).

In the U.S. Pacific Northwest, several species of truffle are harvested both recreationally and commercially, most notably, the Leucangium carthusianum, "Oregon white truffles", Tuber gibbosum, and Tuber oregonense.

The "pecan truffle" (Tuber lyonii)[37] syn. texense[38] is found in the Southern United States, usually associated with pecan trees. Chefs who have experimented with them agree "they are very good and have potential as a food commodity".[39] Although pecan farmers used to find them along with pecans and discard them, considering them a nuisance, they sell for about $100 a pound and have been used in some gourmet restaurants.[citation needed]

Truffle-like species[edit]

The term "truffle" has been applied to several other genera of similar underground fungi. The genera Terfezia and Tirmania of the family Terfeziaceae are known as the "desert truffles" of Africa and the Middle East. "Hart's truffle" is a name for Elaphomycetaceae. Pisolithus tinctorius, which was historically eaten in parts of Germany, is sometimes called "Bohemian truffle".[3]

Extraction[edit]

Trained pig in Gignac, Lot, France
Trained dog in Mons, Var, France
See also truffle hog.
Truffle hog Truffle dog
Keen sense of smell Keen sense of smell
Innate ability to sniff out truffles Must be trained
Tendency to eat truffles once found Easier to control

The female pig's natural truffle-seeking, as well as her usual intent to eat the truffle, is due to a compound within the truffle similar to androstenol, the sex pheromone of boar saliva, to which the sow is keenly attracted.

In Italy, the use of the pig to hunt truffles has been prohibited since 1985 because of damage caused by animals to truffle's mycelia during the digging that dropped the production rate of the area for some years.

Volatile constituents[edit]

External video
“The Chemistry of Truffles, the Most Expensive Food in the World”, Sarah Everts, CEN Online

The volatile constituents responsible for the natural aroma of truffles are released by the mycelia, fruiting body or derive from truffle-associated microbes. The chemical ecology of truffle volatiles is complex, interacting with plants, insects and mammals, which contribute to spore dispersal. Depending on the truffle species, life cycle or location, these are most notably:

  • Sulfur volatiles, which occur in all truffle species, such as dimethyl mono- (DMS), di- (DMDS) and tri- (DMTS) sulfides, as well as 2-methyl-4,5-dihydrothiophene, characteristic of the white truffle T. borchii and bis(methylthio)methane occurring in all species but mostly characteristic of the white truffle T. magnatum. Some of the very aromatic white truffles are notably pungent, even irritating the eye when cut or sliced.
  • Metabolites of non-sulfur amino acid constituents (simple and branched chain hydrocarbons) such as ethylene (produced by mycelia of white truffles affecting root architecture of host tree), as well as 2-methylbutanal, 2-methylpropanal and 2-phenylethanol (also common in baker’s yeast).
  • Fatty acid-derived volatiles (C8-alcohols and aldehydes with a characteristic fungal odor, such as 1-octen-3-ol and 2-octenal). The former is derived from linoleic acid, and produced by mature white truffle T. borchii.

A number of truffle species and varieties are differentiated based on their relative contents or absence of sulfides, ethers or alcohols, respectively. The sweaty-musky aroma of truffles is similar to that of the pheromone androstenol that also occurs in humans.[40] As of 2010, the volatile profiles of seven black and six white truffle species have been studied.[41]

Culinary use[edit]

Truffle oil (olive oil with Tuber melanosporum).

Because of their high price[42] and their pungent aroma, truffles are used sparingly. Supplies can be found commercially as unadulterated fresh produce or preserved, typically in a light brine.

White truffles are generally served raw, and shaved over steaming buttered pasta, salads, or fried eggs. White or black paper-thin truffle slices may be inserted into meats, under the skins of roasted fowl, in foie gras preparations, in pâtés, or in stuffings. Some speciality cheeses contain truffles, as well.

The flavor of black truffles is far less pungent and more refined than that of white truffles. Their strong flavor is often described as syrupy sweet. Black truffles also are used for producing truffle salt and truffle honey.

While in the past chefs used to peel truffles, in modern times, most restaurants brush the truffle carefully and shave it or dice it with the skin on so as to make the most of this valuable ingredient. A few restaurants in Switzerland still stamp out circular discs of truffle flesh and use the skins for sauces.

Truffle oil[edit]

Main article: Truffle oil

Truffle oil is used as a lower-cost and convenient substitute for truffles, to provide flavoring, or to enhance the flavor and aroma of truffles in cooking. Most "truffle oil", however, does not contain any truffles.[43] The vast majority is olive oil which has been artificially flavoured using a synthetic agent such as 2,4-dithiapentane.[43]

Truffle vodka[edit]

Main article: Truffle vodka

The bulk of truffle oil on the market is made with a synthetic ingredient, as are many other truffle products. However, alcohol is now being used to carry the truffle flavour without the need for synthetic flavourings. The first truffle vodka, Black Moth Vodka, is a natural vodka infused with black Périgord truffles (Tuber melanosporum). Although primarily used as a spirit in its own right and mixed in a range of cocktails, truffle vodka is also used by various chefs to flavour dishes by evaporating the alcohol through cooking whilst retaining the truffle aroma.[44]

See also[edit]

References[edit]

  1. ^ a b Brillat-Savarin, Jean Anthelme (1838) [1825]. Physiologie du goût. Paris: Charpentier.  English translation
  2. ^ Chiera, E. (1934), "Nos. 58 and 112", Sumerian Epics and Myths, Chicago 
  3. ^ a b c Ramsbottom J (1953). Mushrooms & Toadstools. Collins. ISBN. 
  4. ^ Benjamin, D. R. (1995), "Historical uses of truffles", Mushrooms: Poisons and Panaceas — A Handbook for Naturalists, Mycologists and Physicians, New York: WH Freeman and Company, pp. 48–50, ISBN 0716726009 
  5. ^ Sahih al-Bukhari, volume 7, number 609.
  6. ^ Ian R. Hall and Alessandra Zambonelli, "Chapter 1: Laying the Foundations" in: Alessandra Zambonelli and Gregory M Bonito, ed.s, Edible Ectomycorrhizal Mushrooms: Current Knowledge and Future Prospects (Berlin & Heidelberg, Germany: Springer Verlag, 2012), § 1.2 Cultivation of Truffles: pp. 4-6.
  7. ^ Rousseau, "Truffes obtenues par la culture de chênes verts" (Truffles obtained by the cultivation of green oaks) in: Exposition universelle de 1855 : Rapports du jury mixte international, volume 1 (Paris, France: Imprimerie Impériale, 1856), pp. 173-174.
  8. ^ Bungten, ulf; Egli, Simon; Schneider, Loic; Von Arx, Georg; Rigling, Andreas; Camarero, Julio; Sangüesa, Gabriel; Fischer, Christine; Oliach, Daniel; Bonet, Jose-Antonio; Colinas, Carlos; Tegel, Willy; Ruiz, Jose; Martinez, Fernando (2015). "Long-term irrigation effects on Spanish holm oak growth and its black truffle symbiont". Agriculture, Ecosystems and Environment. 202: 148–159. doi:10.1016/j.agee.2014.12.016. 
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  18. ^ "Non-cultivated Edible Fleshy Fungi". Retrieved 2008-05-17. ...it has been known for more than a century that truffles were mycorrhizal on various trees such as oak, beech, birch, hazels, and a few others 
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  20. ^ Karen Hansen (Spring 2006). K. Griffith, ed. "Basidiomycota truffles: Cup fungi go underground" (PDF). Newsletter of the FRIENDS of the FARLOW. Harvard University. Retrieved 2008-05-17. Generally, truffles seems to prefer. warm, fairly dry climates and calcareous soils 
  21. ^ "Mushroom Production". Mycology - Uses of Fungi. University of Sydney. June 2004. Archived from the original on 2008-05-01. Retrieved 2008-05-17. The soil of the truffiere tends to be alkaline, calcareous, and well drained. 
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Bibliography[edit]

  • Nowak, Zachary (2015). Truffle: A Global History. The Edible Series. Reaktion. ISBN 978-1780234366. 

External links[edit]