The hazels belong to the genus Corylus which are deciduous (shedding leaves every year) trees as well as huge shrubs that are indigenous to the temperate regions of the Northern Hemisphere. This genus is generally classified as a member of the birch family Betulaceae, while a number of botanists divide the hazels (alongside the hornbeams as well as related genera) into an individual family called Corylaceae.
The hazel trees bear uncomplicated, curved leaves having double-indented borders. The flowers of hazels blossom especially early in the spring, prior to the emergence of the leaves, and are monoecious (having a single-sex catkin). While the male catkins have a light yellow hue and are about 5 cm to 12 cm in length, the female catkins are extremely diminutive and mostly hidden within the buds. Only the vivid red styles of the female catkins, which grow to a length of 1 mm to 3 mm, are detectable. The seeds of this tree are actually nuts that measure 1 cm to 2.5 cm in length and about 1 cm to 2 cm across. These seeds or nuts are enclosed by husks (involucres) that include the nuts either partially or completely.
The form as well as the makeup of the husk, in addition to its growth pattern (irrespective of being a suckering shrub or tree) is actually significant in identifying the various hazel species.
It may be noted that the nuts or seeds of all hazel species can be eaten. In fact, the species called common hazel is cultivated extensively for its nuts. Besides, filbert is possibly the second most widely grown hazel variety. Although nuts are also collected from the other hazel species, besides those collected from filbert, the nuts of other hazel species do not have much commercial value.
The Celts were of the view that people consuming hazelnuts were provided with knowledge and motivation. In fact, there are several deviations of a very old saga which says that as many as nine hazel trees grew surrounding a holy pool, throwing down nuts into the water that were consumed by salmon (the fish that was blessed to the Druids), which assimilated knowledge and wisdom. It was also believed that the number of spots on the body of the salmon indicated the number of nuts they had consumed.
There is also another tale which says that in his effort to become sagacious, a Druid teacher caught one such exceptional salmon and instructed one of his pupils to cook the fish for him, but not eat it himself. While the student was cooking the fish, boiling liquid from the fish splattered on the thumb of the student, who naturally sucked his thumb to cool it, and, in the process, absorbed all the wisdom. This student was named Fionn Mac Cumhail or Fin McCool and later became one of the greatest gallant leaders in Gaelic folklore.
Nuts, leaves, bark, leafy cover of the hazelnut, hard shell.
Hazelnuts have a number of uses, including therapeutic and culinary. They contain high levels of energy and are packed with several nutrients that are beneficial for our health as well as necessary for the best possible health. It may be noted that 100 grams of hazelnut supply our body with 628 calories. Hazelnuts also have a rich content of mono-unsaturated fatty acids, such as oleic acid, in addition to essential fatty acid - linoleic acid - which is useful in lowering the levels of LDL cholesterol or 'bad cholesterol' and augmenting the levels of HDL cholesterol or 'good cholesterol' in the bloodstream. Findings of several scientific studies hint that Mediterranean diet contains a high amount of mono-unsaturated fatty acids and, thereby, assists in averting strokes and coronary artery disease by means of supporting a hale and hearty blood lipid profile.
Besides mono-unsaturated fatty acids, hazelnuts also have a rich vitamin, dietary fiber and mineral content. In addition, they are loaded with phytochemicals that are beneficial for our health. In general, hazelnuts facilitate in protecting us from ailments and many types of cancers.
Hazelnuts offer us several other health benefits; they have very high folate content. In effect, this is a unique characteristic of these nuts. For instance, 100 grams of fresh hazelnuts enclose 113µg of folate. It may be noted that folate is a significant vitamin that facilitates in preventing megaloblastic anemia and most notably, defects of neural tube in the newborn.
These nuts are also a wonderful resource for vitamin E and enclose approximately 15 grams of this nutrient in every 100 gram providing the complete RDA. It may be noted that vitamin E is a potent antioxidant soluble in lipids and it is necessary for sustaining the integration of the cell coatings of the skin and mucous membranes by means of shielding them from detrimental oxygen free radicals.
Similar to almonds, hazelnuts also do not contain gluten and, hence, are a safe substitute for food sources that may be employed in preparing food formulas that are free from gluten for patients who are allergic to wheat, gluten sensitive and enduring celiac disease. Hazelnuts are loaded with several vital B-complex vitamins, for instance, niacin, riboflavin, folate, thiamine, pyridoxine (vitamin B6) as well as pantothenic acid.
Hazelnuts are also a copious source of several vital minerals, such as potassium, manganese, iron, copper, zinc, magnesium, phosphorus and the trace mineral selenium. It may be worth mentioning that manganese and copper are the indispensable co-factors for the antioxidant enzyme called superoxide dismutase. On the other hand, iron aids in preventing the developing microcytic-anemia. Phosphorus and magnesium are two vital constituents of bone metabolism.
The oil extracted from hazelnut has a nut-like fragrance and also possesses a wonderful astringent attribute. This oil is effective in protecting the skin well from aridity. In addition, hazelnut oil has also been employed for culinary purposes as well as in the form of a 'courier' or base oil in conventional medications for aromatherapy, message therapy, in addition to the cosmetic and pharmaceutical industries.
You may consume hazelnuts as they are or eat them after roasting, sweetening or salting. In addition to hazels, filberts are nutty, but still have a pleasing sweet flavour.
Hazelnuts are extensively employed in confectionery products in the form of an addition to biscuits, cakes, sweets and chocolates. Apart from this, the nuts are also used in making hazelnut butter, which is a well-accepted food among people who suffer from allergic reactions from consuming peanuts. Hazelnut butter is also popular owing to its flavour, which is less salty. Nevertheless, compared to soy or peanut butter, it contains more fat.
Normally, the hazelnut grows in the form of a small tree having numerous stems or a bush and is found growing naturally in the southern regions of Europe as well as in Turkey. In the United States, the hazelnut trees are cultivated in the form of trees having a solitary trunk that are able to grow up to a height of 5 meters or ever higher. Every species of hazelnut needs cross-pollination with a view to produce nuts. Therefore, every planting needs either two or even more species in the same area.
If you are growing hazelnuts, you should ensure that the soil is well-rained and the orchards are not located in any place where the soil is shallow, poor drainage or extremely light or heavy. In most cases, the roots of the hazelnut trees or shrubs exist just in the depth of one meter under the soil. Nevertheless, it is important for the soils to be adequately deep to permit the active root systems of the plant to go in up to two to three meters underneath them. It may be noted that the penetration of the roots may, however, be prevented by an absence of aeration, rock or elevated water tables. It may be worth mentioning that hazelnut trees pull moisture from the upper soil layer. In effect, no solitary direction of incline is more improved compared to the other, barring to the extent that it has an effect on the depth of the soil as well as retention of moisture.
In effect, 60 cm of the soil on top may possibly become arid by the time it is the middle of summer, while the soil deeper down is unlikely to become arid till the summer end. Therefore, in this instance irritation will be required to prevail over the condition. The maximum advantage of irrigation when you are trying to establish an orchard is to get large trees more quickly.
The most suitable soil for growth of the hazelnuts ought to be in the range of somewhat acidic to neutral. Hence, it is most important to have a soil test done prior to planting the trees.
Several cultivars of the common hazel (botanical name Corylus avellana) as well as filbert are cultivated in the form of ornamental plants in the gardens, counting the forms having contorted or buckled stems (such as C. avellana 'Contorta', well known as 'Harry Lauder's walking stick' from the plant's mutilated look); plants having weeping boughs (C. avellana 'Pendula) as well as hazel plants having purple colored leaves, such as C. maxima "Purpurea".
Before concluding discussion on this topic, it needs to be noted that hazels are also employed in the form of food plants by the larvae of an assortment of Lepidoptera species.
Chemical analysis of hazel fruit has revealed that it encloses sugar, starch, oil, carbon hydrates, beta-carotene, iron, calcium, protein fats, phosphorus, sulfur, zinc, selenium and other substances. The bark as well as the leaves of hazelnut trees enclose ethereal oil, tannin and quercetin. The fruits of hazelnut trees enclose nearly 70 per cent of the fatty substances and about 20 per cent of nitrate matter.
The infusion prepared from the leaves of hazel trees/ shrubs acts as a blood purifier. On the other hand, the pollens of hazel flowers are being effectively used to treat epilepsy. The decoction prepared from the bark of the hazel tree is employed externally for treating varicose veins as well as different other dermatological and also muscle conditions.
People who are using or intend to use hazelnut especially for therapeutic purposes ought to be aware of the potential side effects of this product. It may be noted that the allergy caused by consumption of hazelnut or products containing it is known as type-I (Ig-E mediated) hypersensitivity response. This occurs to some people who use foods containing hazelnuts. Overall, the allergic reaction caused by hazelnut may possibly be hastened following exposure to the pollen of the hazel tree.
The allergic symptoms caused owing to consumption of hazelnuts or food substances containing them is called 'oral allergy syndrome' and may possibly include irritation or itching in the region of the lips, tongue and the throat with subsequent distension of the lips and throat resulting in breathing troubles. Very often, cross-reaction to specific other seeds, nuts, vegetables and fruits are also widespread. Hence, it is advisable that people who having allergic reactions to hazelnuts ought to keep away from all food preparations containing any hazel product.
It is possible to consume the hazel fruits directly after removing the hull/ husk. In addition, they can also be pulverized and blended with honey for consumption. Different parts of the hazel tree, including the leaves, buds and bark, have dissimilar applications and some of them are discussed briefly below.