Nuts from A to Z, everything you always wanted to know about nuts.
In this article we tried to summarize the main features of all the types of nuts available on Nuturally: their botanical peculiarities, their origin, their history and some curiosities that true nuts lovers must know.
Are you ready to dive into the incredible nuts world?
Shelled giant almonds and peeled giant almonds
Almonds are harvested from the Prunus Amygdalus. California is the world leading producer of almonds, followed by Spain and Italy. In Italy today the crop is popular in the southern regions, in particular in Puglia and Sicily, even though some crops are present with lower levels of business interest in other regions, too. On the market it is possible to find almonds in shell, already shelled and peeled (these being available also as slices, flour or chopped): peeled almonds are nothing more than shelled almonds from which not only the woody shell, but also the tegument or skin (episperma) has been removed. From a nutritional point of view it would be advisable to consume shelled almonds with their cuticle, as it is a source of fibre and vitamin E, which contributes to the reduction of oxidative stress and plays a fundamental role in the protection of the body.
Almonds indicated for human consumption are commonly called "sweet almonds", but it may happen that within the same package there are also some "bitter almonds". Why is that possible? The reason for this lies in the fact that such almonds grow in small quantities directly on the sweet almonds, the same plant therefore produces both sweet and bitter almonds. This happens because in order to obtain more resistant and productive plants almond trees are "grafted" on older plants, the so-called wild almond or bitter almond. It may happen that the original plant manages to produce some fruit which, being morphologically indistinguishable from other almonds, is harvested together with sweet almonds and then ends up on the market.
Despite bitter almonds being considered toxic as they contain amygdalin that decomposes during the process of digestion giving rise to hydrocyanic acid, there is no need to worry, because bitter poisoning in adults occurs after the ingestion of 50-60 pieces, i.e. a very high quantity.
Bertholletia excelsa, generally known as Brazil nut or Amazon nut, is obtained from the fruits of a large tree belonging to the Lecythidaceae family, widespread in all tropical regions even if most of the species are present in the Amazon basin. The Brazil nuts tree can measure over 50 meters in height, has a trunk that reaches 2 meters in diameter and is therefore one of those trees defined as “emerging”.
The Brazil walnut tree can measure more than 50 meters in height, has a trunk that reaches two meters in diameter and is therefore one of those trees defined as "emerging" in the tropical forest: in fact the large foliage dominates most of trees in the forest. It can reach even 500-800 years of life!
A peculiarity of the Brazil nut concerns the fruit: these are in fact large wooden fruits of the size of a coconut (10-15 cm in diameter), reaching weights of even more than two kg. Each “coconut” contains on average between 12 and 20 wedge-shaped seeds that are also protected by a thick woody shell. Since the shell is rather thick and difficult to break, the shelling is usually done by hand by using shell-breaking machines that open the nuts one by one.
The cultivation is rather difficult due to the slow growth and the pollination of the flowers which, due to the characteristic morphology of the flowers themselves, requires a particular kind of bee. This is the reason why the Brazil nut remains linked to the forest and to the local populations whose main sustenance is represented by the cultivation of Brazil nuts. Besides Brazil, this type of walnut grows spontaneously also in Venezuela, Ecuador, Colombia, Guyana, Bolivia and Peru. Within the world market of dried fruit, Brazil nut is the only species whose production is obtained exclusively from natural areas, by manual harvesting the fruit.
The remarkable nutritional properties of this type of nuts combine with its pleasantness of taste. In fact, Brazil nuts are particularly rich in protein, are a source of essential amino acids and vitamins and, unlike all other types of dried fruit, have a high concentration of selenium.
The genus Anacardium comprehends eight species of tropical trees, even though the most widely consumed is the fruit of the species Anacardium occidentale, an evergreen plant which is native to the Amazon basin in north-eastern Brazil but is widely grown in the tropical regions of the world. The cashew plant provides two types of fruit:
- the “false fruit”, i.e. the cashew apple, that may take on a variable colour between yellow and red and a vaguely heart-shaped appearance, hence the name of the plant. The cashew apple is mainly consumed in the producing land as fresh fruit or it can be used for the preparation of jams or juices (Brazil cajuado);
- the “true fruit”, namely the cashew nut, a kidney-shaped nut covered by a thick woody shell, difficult to remove, which grows in the lower outer part of the apple. It is the case of a “real fruit” because it is on this side of the fruit that the new plant will originate. The dried fruit, once shelled and peeled, is generally of a beautiful ivory colour and is mainly exported from the producing countries to be consumed as a natural fruit, toasted or fried.
Shelled hazelnuts and roasted, peeled hazelnuts
The hazelnut, also known under its scientific name Corylus avellana, is a plant that has its natural habitat in Europe and North America. It was already present in the Mediterranean area over 10,000 years ago. It spread spontaneously until man began to cultivate it by refining the techniques as early as the 4th century BC. From the early years of the 20th century intensive production started being an option. The name of the species Corylus avellana comes from the places of major cultivation: Avellino in Italy and Abella in Turkey. The hazelnuts can be found on the market in different ways: in shell, shelled or shelled and peeled (these last ones also chopped or as flour). In order for the external cuticle to be removed, the hazelnuts undergo a roasting process that gives the fruit its characteristic toasted aroma, which is very much appreciated by consumers and is found in many confectionery preparations, such as spreadable creams.
Italy’s most valuable and appreciated varieties are the Tonda di Giffoni in Campania, the Tonda Gentile Romana in Lazio and the Piedmont hazelnut (or Tonda Gentile delle Langhe). These hazelnuts have well-defined characteristics and are considered a territorial speciality of the regions where they are grown, which is why the Tonda Gentile Romana enjoys PGI (Protected Geographical Indication) and PDO (Protected Designation of Origin) certifications.
In ancient times the hazelnut gained a place of honour not only for its nutritional properties that were already known in Greek and Roman times and praised by poets such as Virgil. In fact, the plant was associated with magical qualities, beneficial not only for man, but also able to allow a sort of dialogue with the environment. This is the case of dowsing, for which hazel branches are preferred when looking for water underground, or when identifying the strands of precious metals.
The name of the genus Macadamia is a tribute to the famous Australian scientist John McAdam, colleague of the British botanist Ferdinand von Mueller. Together with Walter Hill (director of the Brisbane Botanical Garden) he was the first to describe this plant native to Australia. Macadamia trees are very long-lived plants that can survive for more than 100 years: in the Brisbane Botanical Garden it is possible to admire a specimen planted in 1858.
Two species of Macadamia are the most common: the smooth-shelled Macadamia integrifolia and the rough-shelled Macadamia tetraphylla. There are more than ten species of Macadamia and the classification cannot yet be said to be complete, but these two are the only ones to produce fruit of commercial importance and among these Macadamia integrifolia is certainly the most widespread.
All species classified to date are native to Eastern Australia with the exception of Macadamia hildebrandii which is native to Indonesia. It is said that long before Australia was discovered by European explorers, the indigenous peoples of the eastern coasts consumed, during their banquets, the delicious seed of an evergreen plant they called "Kindal Kindal".
The main producing and exporting countries for what concerns macadamia nuts are Australia and Hawaii, followed by Brazil, USA (California), Israel, Kenya, Bolivia, New Zealand, South Africa and Malawi.
Macadamia nuts have a high energetic value, approx. 225 kcal per 30 g (that usually correspond to about 10-15 nuts according to the dimensions). The content of monounsaturated fats amounts to about 78% and is very remarkable, since it represents the highest value compared to any other natural oil, including olive oil.
Natural shelled peanuts, natural peeled peanuts and roasted peanuts in shell
Despite being classified as nuts due to their nutritional and morphologic features, peanuts actually belong to the Leguminosae family: after fertilization the flowers are buried in order to give rise to the fruit we all know. The predominant characteristic of the peanut consists in its high protein quality: in fact, today peanuts and peanut butter are the two foods that cover 10% of the recommended dietary allowance (RDA) of protein in the USA.
The most known species, and also the only one to be cultivated due to commercial interest, is the Arachis hypogaea. The main peanut producing countries are: China, India, USA, Nigeria, Sudan, Myanmar, Argentina, Tanzania, Senegal and Chad. Once harvested, peanuts are transported to the processing plants where they are cleaned. If the moisture content of the legume is too high, the peanuts can undergo a drying phase using hot air. The subsequent stages of the processing differ according to the commercial destinations of the peanut. Among these are:
- peanuts in shell: calibration stage by means of rotating cylinders, which also allow the removal of individual legumes and the elimination of stalks;
- shelled peanuts or peeled peanuts: removal of the shell, calibration, possible removal of the cuticle, i.e. peeling that can be done dry, using water, by rotation or chemically, and finally sorting.
Finally, it is the roasting that provides peanuts in shell their typical taste. When roasting, moisture is removed, and both the outer shell and the inner seed take on their characteristic colour. After roasting, the product is ready for further processing or packaging.
Pecans in shell and shelled pecan halves
The plant, which belongs to the Carya genus and according to its botanical classification is known under the scientific name of Carya illinoinensis, may reach a remarkable age and height, up to 30 meters in height. The fruit is a nut enshrined in a thick green cuticle (hull) that divides into 4 parts when ripe.
The pecan, native to the eastern regions of North America on the border with Mexico, is now widespread in all countries with a mild climate, including Israel, Brazil, Australia and, limited to some areas of the southern peninsula, also in Italy. On the market they are mainly to be found shelled, but it is not that rare to find them also in their characteristic elongated smooth shell. The kernel resembles that of common walnuts, but is darker and has a softer, buttery taste, probably also due to its higher fat content.
Thanks to its constituents, the consumption of pecans brings along several benefits to health. First and foremost, they represent a good source of unsaturated fats, including omega-6 fatty acids. These constituents help maintaining LDL cholesterol (known as bad cholesterol) at low levels in the bloodstream, while raising HDL cholesterol levels (good cholesterol), with associated protective function against atherosclerosis and heart disease. Clinical research, published in the Journal of Nutrition in September 2001, found that consuming a handful of pecans a day can help lower cholesterol levels. Other components of this food are phenolic compounds with high antioxidant capacity: this indicates that pecans can be considered an important source of antioxidants.
Pecan nuts are the basis of the recipe for pecan pie, a famous American cake. The origins of this cake are not very clear but it is said that it was French cooks settled in New Orleans who, after meeting the native populations, began to associate pecans with short pastry and maple syrup, in fact this cake resembles a pie made of dried fruit and is usually accompanied with a some ice cream or whipped cream. The pecan pie is prepared and consumed mainly during the holidays, the festive days from Thanksgiving to Christmas.
Pine nuts are the seeds of Pinus pinea, the scientific name of the stone pine. They have been known and used primarily in the Mediterranean region as food for over 2000 years. In fact the first traces of their use date back to 79 BC among the ruins of Pompeii, where they were considered a noble food to the point that they were remembered in mythology as a seed loved by Bacchus. The Pinus pinea, also called stone pine, pine or Italian pine, is native to the Mediterranean coasts and can be found today in almost all of Europe, from Spain to Cyprus, reaching as far as the southern coast of the Black Sea. Pine cones are the fruits of the Pinus pinea, which open when ripe, releasing the seeds, i.e. the so-called pine nuts.
Symbol of death and resurrection, the pine tree was considered a tree of divine references. Starting from its pine cones, whose shape refers to the egg, which is associated with birth and fertility, the tree was celebrated by the populations of the Mediterranean area, including Etruscans, Greeks, Celts and Romans. Famous in ancient Rome was also the ritual belonging to the feast of Arbor Intrat, in which the consecration of the pine tree took place following the myth of Atys. It is said that Atys, a young inhabitant of Phrygia, was so beautiful that he conquered the goddess Cybele herself, becoming her passionate lover. The King of Pessinunte was convinced that the boy had been subjugated and decided thus to separate him from the goddess by offering him his daughter in marriage, thus angering Cybele who manifested herself during the wedding by playing a Pan flute. The sound of the flute drove all guests mad, including Atys himself who mortally mutilated himself with a knife. Zeus, moved to pity for the story, wanted to turn him into an evergreen pine tree, gifting him eternity.
Pine nuts are among the most expensive types of nuts on the market and their harvest is still made today in the traditional way: the workers climb the trees by means of crampons after being tied with safety ropes. Pine cones can reach 15-20 meters in height and cause the ripe pine cones to fall with the help of hooked poles that serve to sever the attachment between the pine cone and the wood. On the ground, other workers collect the fallen pine cones. The manual harvesting of pine cones is a rather dangerous job, very hard, and it is increasingly difficult to find qualified personnel willing to take on this risk. For this reason, some producing countries have introduced automated harvesting systems, especially in low-density pine forests, where the passage of machines, called “shakers” and similar to those used for olive harvesting, is possible.
On the market several varieties of pine nuts may be found with prices and qualities that are different among them. Only one of the varieties belongs to the Pinus pinea and it is the Mediterranean pine nuts, famous for their use in the recipes of various countries, in particular in the production of the pesto. Mediterranean pine nuts certainly rank among the most sought-after pine nuts, but there are also pine nuts of Chinese origin (Pinus koraiensis), shorter and triangular in shape. In fact, China represents one of the main producing and exporting countries of pine nuts. Siberian pine nuts (Pinus sibirica) are instead small and rounded and are produced in rather small quantities in central-southern Siberia and in the far east of Russia where they are considered a food with great nutritional properties. It can be thus said that pine nuts are now known and cultivated in all countries of the world, with qualities that significantly vary according to the climate.
Shelled pistachios, organic giant pistachios in shell and pistachios in shell
The cultivation of pistachios dates back to ancient times: some archaeological findings have shown its use since the 7th millennium BC in Turkey. The plant is native to Syria, but according to some studies the area of its initial cultivation also includes Minor Asia, Palestine and Turkmenistan.
The word “pistachios” comes from the Persian pesteh and the Arabic fustaq: both words are onomatopoeic and resemble the sound that is produced by the shell as it opens when the pistachio is fully ripe.
Pistachio is mentioned in the Bible when it is said that Jacob sent several fruits in homage to the Pharaoh, including pistachios. It was brought to Rome in 30 AC and later spread to Spain. The spread of the pistachio has gradually included China, Caucasian Russia and, for about a century, the United States of America.
The harvest of pistachios is still carried out manually in the Middle East, while in California the harvesting is mechanized, as it uses special shakers that make the fruit fall.
Pistachios are still harvested mainly by hand in the Middle East, while in California the harvesting is mechanized through the use of special shakers that make the fruit fall. The shell of the ripe pistachio opens in a natural way and by compressing the two halves of the shell it is no longer possible to close it because the seed inside has swollen until break. The pistachios harvested when not completely ripe, and therefore still "closed", are opened through immersion in water using two methods: a rapid immersion (2-3 hours) followed by opening with a nutcracker, while the other involves a 12-hour immersion which favours sprouting. The pistachios are then dried with hot air and then open automatically.
Pistachios can be sold in shell, usually roasted and with the addition of salt, or shelled, with the latest being also available as chopped pistachios.
The major producing country is Iran, followed by the USA, Turkey, China, Syria, Greece, Italy, Afghanistan, Pakistan and India. Iran alone fulfils half of the world production, while California covers 20% of it. The Italian production in concentrated in Sicily: the most suitable areas are those in the surroundings of Catania, Agrigento, and Caltanissetta. The plant has its ideal climate in the Etna area, but unfortunately the type of lava soil has always prevented the introduction of any type of mechanization, thus not allowing the reduction of high production costs.
Walnuts in shell and shelled walnuts
The agronomic interest for the walnut is essentially referred to Juglans regia (common walnut), which is the most widespread and best known species of the whole botanical family of Juglandaceae. The walnut tree's bearing is majestic: it can reach a height of 25-30 metres and an age of over 100 years. The walnut is considered as one of the most established expressions of nuts. In the Italian language, the word corresponding to "walnut" indicates both the fruit of the Juglans regia and the botanical combination of hard and woody nuts, protecting a seed.
Native to the Central Asian mountain ranges, the walnut spread all over the world. China is the world's leading producing country, followed by the USA, where production is mainly concentrated in California, and South America, especially Chile and Argentina. The walnuts that are imported to Italy come mainly from California and the nearest France. During the ‘60s Italy was among the main producing countries, then the spread of walnuts has gradually decreased and Italy has become an importing country. Traditionally, the Italian region most linked to the production of walnuts is Campania. There are many cultivars of walnuts that are distributed in different areas of the world, but one of the most famous and commercially appreciated is certainly the Chandler walnut that was patented in California but is currently one of the most cultivated species in the world. Among the Italian varieties, the most famous and prized is the Sorrento walnut, derived from a mutation of the common walnut that occurred in the Sorrento peninsula.
Walnuts are available on the market in different forms: in shell, shelled halves, shelled quarters and other formats depending on the level of breakage of the kernels, as well as chopped and flours.
The classification of shelled walnuts therefore depends on the size of the kernels:
- when most of the kernels are separated into two more or less equal and intact parts, we speak of "shelled walnut halves";
- when most of the kernels are separated longitudinally into four more or less equal pieces, we speak of "shelled walnut quarters".
Importance to the plant is given by the rich mythological, religious and historical literature that involves it. The name of the genus Juglans comes from the Latin Iovis glans meaning "Jupiter's acorn", i.e. a tree that was excluded from Eden and under which witches gather for their rituals. Thanks to its nutritional virtues the walnut also plays a leading role in nutrition and the similarity of the seed with the human brain was celebrated for its health-giving features even before real chemical and scientific evidence was available.
Sources:
Nuts Book – Nuts for life
www.consumer.bz.it/it/le-mandorle-amare-sono-tossiche
https://americanfoodshop.it/blog/pecan-pie-ricetta-originale-americane-della-torta-alle-noci-pecan/
www.nuturally.com/magazine/en/much-nuts-and-dried-fruit-should-be-eaten-day/