Allium cepa, commonly known as the onion, belongs to the Alliaceae family along with shallots, chives, and garlic. It was previously classified incorrectly and grouped in the Amaryllidaceae family, whose members include daffodils, amaryllis and various other plants with bulbs. The onion plant is made up of superficial roots attached to a bulb, and has green tube-like leaves extending out of the bulb. The bulb is composed of numerous concentricleaves that act as storage for food. The bulbs come in many shapes and colours. As the onion plant becomes mature, it generates a seed stalk at the end from where bluish or white flowers grow in a circular cluster known as the umbel. Some varieties or onions also produce tiny bulblike formations referred to as the bulbils.
White, Spanish (yellow), and red are the three main varieties of onions cultivated. These varieties vary in shape, size, colour, and pungency. Numerous new hybrid variations have been developed with reduced amounts of the sulphuric compounds. It is the sulphuric compounds that are responsible for giving onions their sharp flavour and making the eyes sting. The sharp tasting varieties lose their flavour upon cooking as the sulphuric compounds are broken down. Cooked onions may actually end up tasting sweeter than the new sweet varieties developed for raw consumption.
Green onions are called scallions or spring onions and differ from regular onions only at the time in which they are harvested. Green onions are picked when their tops are still green and the bulbs are less than 13 mm in diameter. They have a milder flavour and the whole plant, including the top, bulb, and stem, are all edible. Normally, spring onions are used as a garnish, raw in salads or sauces, and for seasoning purposes in prepared dishes. Onions can be purchased in a number of different forms including pickled, boiled, frozen, and dried.
History of the Onion
Origin of the onion is disputed as it does not preserve too well for archaeological objectives. Some historians argue they first appeared in central Asia while others assert that they first appeared further west in what is today Iran and Pakistan. What can be stated with certainty is that they showed up in the Mediterranean area as far back as 5000 years ago, as records of the onion exist in the earliest recorded books of the Bible. In all probability, the name onion is derived from the Latin unus, translating to “one”.
Due to its structure of “circle-within-a-circle” and the spherical bulbs, onions represented the universe and eternal life in Egyptian culture. They were used to fill the eye sockets of Pharaoh Ramses IV when his body was mummified. Onions were also placed in the pyramids with kings like Tutankhamen, to be carried into the after-life as gifts with spiritual meaning. The workers building the pyramids were paid in onions. Indians first hinted at the medicinal value of onions in the sixth century BC, claiming they had diuretic properties and were good for digestion, heart, joints, and eyes. The Romans carried onions on their journeys and introduced them to Britain. In the Middle Ages they were used to treat snakebites and as payment for rent. The Pilgrims carted onions to the Americas only to discover that they already had their own wild varieties. American Indians used onions in their stews. Christopher Columbus presented the onion to the West Indies from where their cultivation proliferated. Now India, China, the US, Russia, and Spain, are the world’s major onion producers.
Onions hold a special place in folklore and magic. As a protective shield, onions grown in pots and gardens are said to guard against evil. When carried on person, they keep venomous creatures at bay, and when placed in charms they keep children protected against ghosts. Onions are long believed to have healing powers. A cut-up onion distributed around the house is said to absorb evil and disease. To treat warts, just rub with an onion, and then discard over the right shoulder and walk off without turning back. New England settlers placed strings of onions on entrances to shield against infections, and an onion strategically placed under a sink serves the same purpose. Red onions tied to bed posts offer protection against sickness. In times of tough decisions, placing an onion under the pillow is said to generate prophetic dreams.
Health Benefits of the Onion
Onions have been in existence for thousands of years, and the list of time-tested benefits of this simple vegetable have only grown. Onions are frequently used to avert tooth decay and oral infections. Chewing a raw onion for a few minutes potentially kills harmful germs in the mouth, throat, and around lips. Alternatively, the consumption of equal parts of onion juice and honey can aid in the relief of sore throats and coughing. Additionally, the consumption of onion helps to decrease the pain linked with inflammatory conditions such as gout and arthritis. Onions are well recognised for their anti-inflammatory properties. A mixture of onion juice and olive oil, or honey, applied to the face, is said to be a good treatment for acne, and cuts down on swelling associated with acne. Onions contain compounds called saponins which are anti-spasmodic; making them useful for relieving an upset stomach.
The phytochemicals in onions stimulate vitamin C within the body which in turn heightens the immune system to protect against toxins and other foreign substances that may cause illness. Onions also act as anticoagulants, meaning they behave as blood thinners. The ability to prevent clots from forming leads to improved cardiovascular health.
Onions contain the compound chromium, a mineral which is hardly ever found occurring naturally in food items. Chromium ensures the slow release of glucose to body cells and muscles. Eating onions helps to moderate blood sugar levels, which is of critical importance to diabetics.
The pain from bee stings can be reduced by applying onion juice to the affected area, and is also effective against scorpion stings and various other types of insect bites. The rather sharp smell of onion causes insects to take flight, which makes this vegetable a good insect repellent. A few drops of onion juice can provide relief from acute earache and potentially eliminate ringing sounds in the ear.
Onions are loaded with quercetin, an antioxidant that is linked with inhabitation and development of cancer cells. Vitamin C, another antioxidant found in abundance in onions, cuts down on the impact of free radicals in the body. Free radicals are products of cell metabolism that can turn healthy cells into cancerous ones. All antioxidant rich foods neutralize free radicals. Studies show that that the protective effect of onions is related to any cancer cells in the body and are not linked to any specific tissue like breast or lung.
A newly identified compound in onions is said to inhibit bone loss in menopausal women, and rival Fosamax, the prescription drug. Onions are also rich in sulphuric compounds that prevent formations of biochemical chains. It is believed that these chains may lead to asthmatic conditions. These sulphuric compounds also aid in the melting of phlegm in patients with severe coughing.
Being a member of the Allium family, onions are rich in sulphur compounds. In addition to giving them the pungent odour, these compounds also provide them with their health promoting properties. Onions possess a wide variety of allyl sulphides, including the four most important ones and a wide array of sulfoxides. Additionally, onions are a good source of polyphenols, which include flavonoid polyphenols. The flavonoid quercetin is found in particularly large quantities. Generally speaking, the red onions have a much higher total value of the flavonoids compared to white onions, with the yellow falling somewhere in the middle. Onions are also a good source of vitamin C, enzyme initiating manganese, along with molybdenum, chromium, B6, fibre, folate and potassium.
How to Use Onions
Onions are used in an endless variety of ways within different cultures. The most common use is to add it raw in salads or as garnish. However, some people find them to be a bit too pungent for their tastes. One way to lessen the onion's bite is to cut them up according to needs. That might be slicing, mincing, or chopping. Then just rinse the pieces under cold water for roughly one minute, and for onions with stronger bite, let them sit in cold water for a few minutes. Then spread the washed onion on a paper towel and pat dry. The rinsing or soaking removes most of the pungency released when the onion is cut. The final raw product will be significantly sweeter too.
Caramelising onions is another way to remove the pungency and bring out the natural flavour. All varieties of onions can be caramelised, although some will caramelise faster than others. The time needed to caramelise is determined by the amount of sugars in the onions. To caramelise an onion, cut one medium sized vegetable into long thin slices and put aside. Heat a few teaspoons of oil or butter, depending on taste, and bring to a medium-high temperature. The oil is sufficiently hot when it begins to ripple. Add the onion and stir until all the pieces are lined with the oil. Add a pinch of salt, as it will help to season the onion and speed up the caramelising process. This is because the salt draws out all the moisture from the onion thus allowing it to evaporate. If desired, add some black pepper at this point to further season the onion. Once the onions turn lightly red remove them from heat. The caramelised onions can now be used in sandwiches, salads, salsas, as side dishes with omelette, sauces, and in many other of different ways.
Many independent studies and trials have been conducted to understand the effects that onions have on different illnesses. One study, using data from southern European population, found a definite reduction in the risks of a number of common cancers with an increased use of onions. Another study investigated the clinical hypoglycaemic effects of onions on diabetic patients. It was found that the consumption of just 100 grams of raw onions helped to reduce the level of sugar in blood considerably. In a third study, Allium plants, like onion, showed antibiotic action against gram-positive and gram-negative bacteria.