Hazelnut

Hazelnut

Discussion
Ask a question about 'Hazelnut'
Start a new discussion about 'Hazelnut'
Answer questions from other users
Full Discussion Forum
 
Encyclopedia
A hazelnut is the nut
Nut (fruit)
A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...

 of the hazel and is also known as a cob nut or filbert nut according to species. A cob is roughly spherical to oval, about 15–25 mm long and 10–15 mm in diameter, with an outer fibrous husk surrounding a smooth shell. A filbert is more elongated, being about twice as long as it is round. The nut falls out of the husk when ripe, about seven to eight months after pollination. The kernel
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

 of the seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

 is edible and used raw or roasted, or ground into a paste. Hazelnuts are also used for livestock feed, as are chestnut
Chestnut
Chestnut , some species called chinkapin or chinquapin, is a genus of eight or nine species of deciduous trees and shrubs in the beech family Fagaceae, native to temperate regions of the Northern Hemisphere. The name also refers to the edible nuts they produce.-Species:The chestnut belongs to the...

s and acorn
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...

s. The seed has a thin dark brown skin, which is sometimes removed before cooking.

Hazelnuts are produced in commercial quantities in Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 and in the American states of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

 and Washington. Turkey is, by far, the largest producer of hazelnuts in the world.

Hazelnuts are used in confectionery
Confectionery
Confectionery is the set of food items that are rich in sugar, any one or type of which is called a confection. Modern usage may include substances rich in artificial sweeteners as well...

 to make praline
Praline
Praline is a family of confections made from nuts and sugar syrup.-Europe:As originally inspired in France at the Château of Vaux-le-Vicomte by the cook of the 17th-century sugar industrialist Marshal du Plessis-Praslin , early pralines were whole almonds individually coated in caramelized sugar,...

, and also used in combination with chocolate
Chocolate
Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...

 for chocolate truffle
Chocolate truffle
A chocolate truffle is a type of chocolate confectionery, traditionally made with a chocolate ganache center coated in chocolate or cocoa powder, usually in a spherical, conical, or curved shape...

s and products such as Nutella
Nutella
Nutella is the brand name of a chocolate spread. Nutella, manufactured by the Italian company Ferrero, was introduced on the market in 1963. The recipe was developed from an earlier Ferrero spread released in 1944. Nutella is now sold in over 75 countries....

. Hazelnut oil, pressed from hazelnuts, is strongly flavoured and used as a cooking oil.

Hazelnuts are rich in protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 and unsaturated fat
Unsaturated fat
An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fat molecule is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond. Where double bonds are formed, hydrogen atoms are...

. Moreover, they contain significant amounts of thiamine
Thiamine
Thiamine or thiamin or vitamin B1 , named as the "thio-vitamine" is a water-soluble vitamin of the B complex. First named aneurin for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are...

 and vitamin B6
Vitamin B6
Vitamin B6 is a water-soluble vitamin and is part of the vitamin B complex group. Several forms of the vitamin are known, but pyridoxal phosphate is the active form and is a cofactor in many reactions of amino acid metabolism, including transamination, deamination, and decarboxylation...

, as well as smaller amounts of other B vitamins.

Historical Cultivation


In 1995 evidence of large-scale Mesolithic
Mesolithic
The Mesolithic is an archaeological concept used to refer to certain groups of archaeological cultures defined as falling between the Paleolithic and the Neolithic....

 nut processing, some 9,000 years old, was found in a midden
Midden
A midden, is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, vermin, shells, sherds, lithics , and other artifacts and ecofacts associated with past human occupation...

 pit on the island of Colonsay
Colonsay
Colonsay is an island in the Scottish Inner Hebrides, located north of Islay and south of Mull and has an area of . It is the ancestral home of Clan Macfie and the Colonsay branch of Clan MacNeill. Aligned on a south-west to north-east axis, it measures in length and reaches at its widest...

 in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

. The evidence consists of a large, shallow pit full of the remains of hundreds of thousands of burned hazelnut shells. Hazelnuts have been found on other Mesolithic sites, but rarely in such quantities or concentrated in one pit. The nuts were radiocarbon dated
Radiocarbon dating
Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...

 to 7720+/-110BP, which calibrates to circa 7000 BC. Similar sites in Britain are known only at Farnham
Farnham
Farnham is a town in Surrey, England, within the Borough of Waverley. The town is situated some 42 miles southwest of London in the extreme west of Surrey, adjacent to the border with Hampshire...

 in Surrey
Surrey
Surrey is a county in the South East of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire and Berkshire. The historic county town is Guildford. Surrey County Council sits at Kingston upon Thames, although this has been part of...

 and Cass ny Hawin on the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...

. See also Sruwaddacon Bay, Kilcommon
Kilcommon
Kilcommon is a civil parish in Erris, north Mayo consisting of two large peninsulas; Dún Chaocháin and Dún Chiortáin. It consists of 37 townlands, some of which are so remote that they have no inhabitants...

, Erris
Erris
Erris is a barony in northwestern County Mayo in Ireland consisting of over , much of which is mountainous blanket bog. It has extensive sea coasts along its west and north boundaries. The main towns are Belmullet and Bangor Erris. The name Erris derives from the Irish 'Iar Ros' meaning 'western...

, County Mayo
County Mayo
County Mayo is a county in Ireland. It is located in the West Region and is also part of the province of Connacht. It is named after the village of Mayo, which is now generally known as Mayo Abbey. Mayo County Council is the local authority for the county. The population of the county is 130,552...

, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

.

This discovery gives an insight into communal activity and planning in the period. The nuts were harvested in a single year and pollen analysis
Pollen analysis
Analysis of the distribution of pollen grains of various species contained in surface layer deposits, especially peat bogs and lake sediments, from which a record of past climate may be inferred. Because the lake sediments accumulate over time, a core of the mud will show that the mud at the bottom...

 suggests that the hazel
Hazel
The hazels are a genus of deciduous trees and large shrubs native to the temperate northern hemisphere. The genus is usually placed in the birch family Betulaceae, though some botanists split the hazels into a separate family Corylaceae.They have simple, rounded leaves with double-serrate margins...

 trees were all cut down at the same time. The scale of the activity, unparalleled elsewhere in Scotland, and the lack of large game on the island, suggest the possibility that Colonsay contained a community with a largely vegetarian diet for the time they spent on the island. The pit was originally on a beach close to the shore, and was associated with two smaller stone-lined pits, whose function remains obscure, a hearth, and a second cluster of pits.

Because hazelnuts do not generally need to be toasted, indeed Kentish Cobnuts are still traditionally sold fresh, it has been speculated this was done to make them more digestible for children. It is also thought that toasting the nuts increased how long they would keep, and they have historically been a useful food for mariners because they keep well.

Hazel has been grown historically in coppices for use in wattle and daub buildings, and in hedges. The Romans cultivated hazelnuts including in Britain, although there is no evidence that they spread specific cultivars. Cultivated varieties have been grown since at least the 16th Century, with a great increase in varieties during the 1800's, in particular the first really widespread cultivar the Kentish Cobnut was introduced in 1830.

The traditional method to increase nut production is called 'brutting', which involves prompting more of the trees energy to go into flower bud production, by snapping but not breaking off the tips of the new years shoots six or seven leaf groups from the join with the trunk or branch, at the end of the growing season. The traditional term for an area of cultivated hazelnuts is a plat.

Modern Cultivation


Common hazel is widely cultivated for its nuts, including in commercial
Commerce
While business refers to the value-creating activities of an organization for profit, commerce means the whole system of an economy that constitutes an environment for business. The system includes legal, economic, political, social, cultural, and technological systems that are in operation in any...

 orchard
Orchard
An orchard is an intentional planting of trees or shrubs that is maintained for food production. Orchards comprise fruit or nut-producing trees which are grown for commercial production. Orchards are also sometimes a feature of large gardens, where they serve an aesthetic as well as a productive...

s in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

 and the Caucasus
Caucasus
The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...

. The name "hazelnut" applies to the nuts of any of the species of the genus Corylus. This hazelnut, the kernel
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

 of the seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

, is edible and used raw or roasted, or ground into a paste
Spread (food)
A spread is a food that is spread with a knife onto bread, crackers, or other bread products. Spreads are added to bread products to provide flavor and texture, and are an integral part of the dish, i.e. they should be distinguished from condiments, which are optional additions...

. The seed has a thin dark brown skin, which has a bitter flavour and is sometimes removed before cooking. The top producer of hazelnuts, by a large margin, is Turkey, specifically the Ordu Province
Ordu Province
Ordu Province is a province of Turkey, located on the Black Sea coast. Its adjacent provinces are Samsun to the northwest, Tokat to the southwest, Sivas to the south, and Giresun to the east. Its traffic code is 52...

. Turkish hazelnut production of 625,000 tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...

s accounts for approximately 75% of worldwide production.

In North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

: in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, hazelnut production is concentrated in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

; they are also grown extensively just to the north, in the Fraser Valley
Fraser Valley
The Fraser Valley is the section of the Fraser River basin in southwestern British Columbia downstream of the Fraser Canyon. The term is sometimes used to refer to the Fraser Canyon and stretches upstream from there, but in general British Columbian usage of the term refers to the stretch of the...

 of British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

. In 1996, the in-shell production in Oregon was about 19,900 ton
Short ton
The short ton is a unit of mass equal to . In the United States it is often called simply ton without distinguishing it from the metric ton or the long ton ; rather, the other two are specifically noted. There are, however, some U.S...

s (18,000 tonnes), compared to 100 tons (91 tonnes) in Washington. Hazelnuts are also found in the Pangi valley of Chamba district in India, where they are known as thangi. The hazelnut is growing in popularity in the U.S., where the Hazelnut Marketing Board was established in 1949 by Federal Hazelnut Marketing Order section 982. The harvesting of hazelnuts is done either by hand or by manual or mechanical raking of fallen nuts.


Cultivars


There are many cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s of the hazel, including 'Barcelona', 'Butler', 'Casina', 'Clark' 'Cosford', 'Daviana', 'Delle Langhe', 'England', 'Ennis', 'Fillbert', 'Halls Giant', 'Jemtegaard', 'Kent Cob', 'Lewis', 'Tokolyi', 'Tonda Gentile', 'Tonda di Giffoni', 'Tonda Romana', 'Wanliss Pride', and 'Willamette'. Some of these are grown for specific qualities of the nut; these qualities include large nut size and early and late fruiting cultivars, whereas others are grown as pollinators. The majority of commercial hazelnuts are propagated from root sprouts. Some cultivars are of hybrid origin between common hazel
Common Hazel
Corylus avellana, the Common Hazel, is a species of hazel native to Europe and western Asia, from the British Isles south to Iberia, Greece, Turkey and Cyprus, north to central Scandinavia, and east to the central Ural Mountains, the Caucasus, and northwestern Iran. It is an important component of...

 and filbert. One cultivar grown in Washington state, the "DuChilly", has an elongated appearance, a thinner and less bitter skin, and a distinctly sweeter flavor than other varieties.

Turkish hazelnut


Turkish hazelnuts are not to be confused with the wild hazelnut of Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

, Corylus colurna, whose small fruit make it useful only as rootstock
Rootstock
A rootstock is a plant, and sometimes just the stump, which already has an established, healthy root system, used for grafting a cutting or budding from another plant. The tree part being grafted onto the rootstock is usually called the scion...

. The Turkish nuts are categorized into two in terms of quality, Ordu
Ordu
Ordu 'army') is a port city on the Black Sea coast of Turkey, and the capital of Ordu Province. Estimated population c. 2010: 141,341.-Etymology:...

 Levant and Giresun.

Ordu Levant Quality: This is the common name given to all hazelnuts that are grown in regions other than the region of Giresun quality hazelnut. Called Levant
Levant
The Levant or ) is the geographic region and culture zone of the "eastern Mediterranean littoral between Anatolia and Egypt" . The Levant includes most of modern Lebanon, Syria, Jordan, Israel, the Palestinian territories, and sometimes parts of Turkey and Iraq, and corresponds roughly to the...

 Akçakoca, Levant Ordu, Levant Trabzon or Levant Samsun depending on the place they are grown.

Giresun Quality: Fat hazelnuts grown in the entire province of Giresun
Giresun
Giresun is the provincial capital of Giresun Province in the Black Sea Region of northeastern Turkey, about west of the city of Trabzon.-Etymology:...

 and fat hazelnuts grown in Beşikdüzü, Vakfıkebir, Çarşıbaşı and Akçaabat towns of the province of Trabzon, which are more or less similar to Giresun quality.

Harvesting



Hazelnuts are harvested annually in mid-autumn. As autumn comes to a close, the trees drop their nuts and leaves. Most commercial growers wait for the nuts to drop on their own, rather than use equipment to shake them from the tree.

There are four primary pieces of equipment used in commercial harvesting the sweeper, the harvester, the nut cart and the forklift. The sweeper moves the nuts into the center of the rows, the harvester lifts and separates the nuts from any debris (i.e. twigs and leaves), the nut cart holds the nut picked up by the harvester, and the forklift brings a tote to offload the nuts from the nut cart and then stacks the totes to be shipped to the processor (nut dryer).
The sweeper is a low-to-the-ground machine that makes two passes in each tree row. It has a 2 m belt attached to the front that rotates to sweep leaves, nuts, and small twigs from left to right, depositing the material in the row's center as it drives forward. On the rear of the sweeper is a powerful blower to blow material left into the adjacent row with air speeds up to 90 m/s. Careful grooming during the year and patient blowing at harvest can eliminate the need for hand raking around the trunk of the tree, where nuts can accumulate. The sweeper prepares a single center row of nuts narrow enough for the harvesting tractor to drive over without driving on the center row. It is best to only sweep a few rows ahead of the harvesters at any given time. The reason for this is to prevent the tractor that drives the harvester from crushing the nuts that may still be falling from the trees. Hazelnut orchards may be harvested up to three times during the harvest season, depending on the quantity of nuts in the trees and the rate of nut drop as a result of weather.

The harvester is a slow-moving machine pulled by a tractor, which lifts the material off the ground and separates the nuts from the leaves, empty husks, and twigs. As the harvester drives over the rows, a rotating cylinder with hundreds of tines rakes the material onto a belt. The belt takes the material over a blower and under a powerful vacuum that sucks the lightweight dirt and leaves from the nuts, and discharges it into the orchard. The remaining nuts are conveyed into a nut cart pulled behind the harvester. The forklift will bring a tote box to offload the nuts from the nut cart.

Once a tote is filled with nuts, the forklift will haul away the full totes and bring empties back to the harvester to maximize the harvester's time.

There are two different timing strategies for collecting the fallen nuts. The first is to harvest early when approximately half of the nuts have fallen. With less material on the ground, the harvester can work faster with less chance of a breakdown. The second option is to wait for all the nuts to fall and harvest. Though the first option is considered the better of the two, it requires longer to perform due to the need for two or three subsequent passes. Weather must also be a consideration. Rain inhibits harvest and should a farmer wait for all the nuts to fall after a rainy season, it becomes much more difficult to harvest. Pickup also varies with how many acres are being farmed and the number of sweepers, harvesters, nut carts and forklifts available.

A dry orchard can be dusty, so equipment operators should wear breathing protection. Conversely if it is too wet, mud cakes in the machinery and moisture weighs down the material, making it impossible for the equipment to function without picking up large quantities of mud.

Culinary Uses


Hazelnuts are used in confectionery
Confectionery
Confectionery is the set of food items that are rich in sugar, any one or type of which is called a confection. Modern usage may include substances rich in artificial sweeteners as well...

 to make some praline
Praline
Praline is a family of confections made from nuts and sugar syrup.-Europe:As originally inspired in France at the Château of Vaux-le-Vicomte by the cook of the 17th-century sugar industrialist Marshal du Plessis-Praslin , early pralines were whole almonds individually coated in caramelized sugar,...

s, in chocolate
Chocolate
Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...

 for some chocolate truffle
Chocolate truffle
A chocolate truffle is a type of chocolate confectionery, traditionally made with a chocolate ganache center coated in chocolate or cocoa powder, usually in a spherical, conical, or curved shape...

s, and in some hazelnut paste products (such as Nutella
Nutella
Nutella is the brand name of a chocolate spread. Nutella, manufactured by the Italian company Ferrero, was introduced on the market in 1963. The recipe was developed from an earlier Ferrero spread released in 1944. Nutella is now sold in over 75 countries....

). In the United States, hazelnut butter
Nut butter
A nut butter is a spreadable foodstuff made by crushing nuts. The result has a high fat content and can be spread like true butter, but is otherwise unrelated...

 is being promoted as a more nutritious spread than its peanut butter
Peanut butter
Peanut butter is a food paste made primarily from ground dry roasted peanuts, popular in North America, Netherlands, United Kingdom, and parts of Asia, particularly the Philippines and Indonesia. It is mainly used as a sandwich spread, sometimes in combination as in the peanut butter and jelly...

 counterpart, though it has a higher fat content. In Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

 and especially in Vienna
Wien
Wien is the German language name for Vienna, the city and federal state in Austria.* Wien , in Vienna, Austria* Theater an der Wien, a theater in Vienna located at the former river WienWien may also refer to:...

, hazelnut paste is an ingredient in the making of tortes (such as Viennese hazelnut torte) which are famous there. Hazelnuts are also the main ingredient of the classic Dacquoise
Dacquoise
A dacquoise is a dessert cake made with layers of almond and hazelnut meringue and whipped cream or buttercream. It takes its name from the feminine form of the French word dacquois, meaning 'of Dax', a town in southwestern France. It is usually served chilled and accompanied by fruit...

 liqueur. Hazelnut liqueur
Liqueur
A liqueur is an alcoholic beverage that has been flavored with fruit, herbs, nuts, spices, flowers, or cream and bottled with added sugar. Liqueurs are typically quite sweet; they are usually not aged for long but may have resting periods during their production to allow flavors to marry.The...

s, such as Frangelico
Frangelico
Frangelico is a brand of noisette, or hazelnut and herb-flavored liqueur which is produced in Canale, Italy. It is 20% alcohol by volume, 40 proof. It was released in the 1980s, gaining attention largely because of its unusual packaging: its bottle was designed to look like a friar, complete with...

, are Vodka
Vodka
Vodka , is a distilled beverage. It is composed primarily of water and ethanol with traces of impurities and flavorings. Vodka is made by the distillation of fermented substances such as grains, potatoes, or sometimes fruits....

-based.

Hazelnut-flavoured coffee seems (to many users) to be slightly sweetened and less acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

ic, even though the nut is low in natural saccharides. The reason for such perception is not yet understood.

In Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, over 2,000 tonnes are imported annually, mostly to supply the demand from the Cadbury company. Hazelnut oil, pressed from hazelnuts, is strongly flavoured and used as a cooking
Cooking
Cooking is the process of preparing food by use of heat. Cooking techniques and ingredients vary widely across the world, reflecting unique environmental, economic, and cultural traditions. Cooks themselves also vary widely in skill and training...

 oil. Hazelnuts are also grown extensively in Australia, in orchards growing varieties mostly imported from Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. It is also grown in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 and Chile.

Common hazel is used by a number of species of Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

 as a food plant.

Cancer medication


Recently a group of Italian researchers in the Department of Translational Oncology, National Institute for Cancer Research, IST, Genova with the collaboration of the University of Genova, Italy, has confirmed the presence of taxane
Taxane
The taxanes are diterpenes produced by the plants of the genus Taxus . As their name suggests, they were first derived from natural sources, but some have been synthesized artificially. Taxanes include paclitaxel and docetaxel . Paclitaxel was originally derived from the Pacific yew tree.Taxanes...

s in the shells and leaves of hazel plants, including paclitaxel
Paclitaxel
Paclitaxel is a mitotic inhibitor used in cancer chemotherapy. It was discovered in a U.S. National Cancer Institute program at the Research Triangle Institute in 1967 when Monroe E. Wall and Mansukh C. Wani isolated it from the bark of the Pacific yew tree, Taxus brevifolia and named it taxol...

, 10-deacetylbaccatin III, baccatin III, paclitaxel C, and 7-epipaclitaxel. The finding of these compounds in shells, which are considered discarded material and are mass produced by many food industries, is of interest for the future availability of paclitaxel (Taxol).

Health benefits



Hazelnuts have a significant place among the types of dried nuts in terms of nutrition and health because of the special composition of fats (primarily oleic acid
Oleic acid
Oleic acid is a monounsaturated omega-9 fatty acid found in various animal and vegetable fats. It has the formula CH37CH=CH7COOH. It is an odorless, colourless oil, although commercial samples may be yellowish. The trans isomer of oleic acid is called elaidic acid...

), protein, carbohydrates, vitamins (vitamin E), minerals, dietary fibres, phytosterol
Phytosterol
Phytosterols, which encompass plant sterols and stanols, are steroid compounds similar to cholesterol which occur in plants and vary only in carbon side chains and/or presence or absence of a double bond. Stanols are saturated sterols, having no double bonds in the sterol ring structure. More than...

 (beta-cytosterol) and antioxidant phenolics such as flavan-3-ol
Flavan-3-ol
Flavan-3-ols are a class of flavonoids that use the 2-phenyl-3,4-dihydro-2H-chromen-3-ol skeleton. These compounds include the catechins and the catechin gallates....

s.