Onions and garlic have been valued for thousands of years for culinary, medicinal and other uses. Some facts and folklore about the onions and garlic.
The onion (Allium cepa), which is also known as the bulb onion, common onion is the most widely cultivated species of the genus Allium. The genus Allium also contains a number of other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion (A. fistulosum), Egyptian onion (A. ×proliferum), and Canada onion (A. canadense). The name “wild onion” is applied to a number of Allium species. Onion is most frequently a biennial, although it can also be a triennial or a perennial. The vast majority of cultivars of A. cepa belong to the “common onion group” (A. cepa var. cepa) and are usually referred to simply as “onions”. The Aggregatum Group of cultivars (A. cepa var. aggregatum) includes both shallots and potato onions.
Allium cepa is known exclusively in cultivation, but related wild species occur in Central Asia. The most closely related species include Allium vavilovii(Popov & Vved.) and Allium asarense (R.M. Fritsch & Matin) from Iran. However, Zohary and Hopf warn that “there are doubts whether the A. vaviloviicollections tested represent genuine wild material or only feral derivatives of the crop.”
The common onion is part of the Allium or lily plant family, which includes garlic, chives, leeks and shallots. The onion gets its name from the Latin word uniowhich means ‘one’ or ‘single’, as onions are different than garlic, which produces many small bulbs while the onion produces only one. Traces of onions have been found in Bronze Age settlements dating back to 5000 B.C.E. Alexander the Great fed his army onions with the belief that if they ate strong foods, they themselves would become stronger. Onions have strong antiseptic qualities, and their juice has been used for cleansing and healing wounds for centuries, all the way up to the American Civil War. When The Plague infected Europe, some believed it was caused by evil spirits. Some would wear strings of onions around their necks to try and protect themselves.
Onions have also been used for other varieties of ailments through the centuries. In ancient India they were used as a diuretic, in China they were used for many things like liver disease, constipation and wound healing. In Colonial America eating a raw wild onion was thought to cure measles. There is medical research that proves onions are indeed a healthy vegetable. They can lower blood glucose, lower blood pressure, lower overall cholesterol, dissolve blood clots and help prevent cancer. There are two general categories of onions. Fresh spring/summer onions and storage onions. Fresh onions can be any color, some have their green stems attached. They are generally milder than storage onions. Storage onions can be red, yellow or white. They can range in flavor from mild to really strong, but most storage onions sweeten up and become mild when cooked.
Onions are often chopped and used as an ingredient in various hearty warm dishes, and may also used as a main ingredient in their own right, for example in French onion soup or onion chutney. They are also used raw in cold salads. Onions are also used as a thickening agent for curries providing a bulk of the base. Onions pickled in vinegar are eaten as a snack. These are often served as a side serving in fish and chip shops throughout theUnited Kingdom and Australia, often served with cheese in the United Kingdom, and as “pickled onions” in Eastern Europe. Fresh onion has a pungent, persistent, even irritating taste, but when sautéed, onion becomes sweet and much less pungent. Everybody who has ever had to cut up a lot of strong onions knows what happens. It is literally a job that makes all of us cry. That is because onions contain sulfur, and when you cut the onion sulfur is released into the air. This air-borne sulfur reacts with the moisture in your eyes and creates a mild form of sulfuric acid! Your eyes tear up to flush this substance from your eyes.
Common onions are normally available in three colours: yellow, red, and white. Yellow onions, also called brown onions, are full-flavoured and are a reliable standby for cooking almost anything. Yellow onions turn a rich, dark brown when cooked and give French onion soup its tangy sweet flavour. The red onion is a good choice for fresh uses or in grilling and char-broiling. White onions are the traditional onion used in classic Mexican cuisine. They have a golden colour and sweet flavour when sautéed. While the large mature onion bulb is the onion most often eaten, onions can be eaten at immature stages. Young plants may be harvested before bulbing occurs and used whole as scallions. When an onion is harvested after bulbing has begun but the onion is not yet mature, the plants are sometimes referred to as summer onions. Additionally, onions may be bred and grown to mature at smaller sizes. Depending on the mature size and the purpose for which the onion is used, these may be referred to as pearl, boiler, or pickler onions. (However, true pearl onions are a different species.) Pearl and boiler onions may be cooked as a vegetable rather than an ingredient. Pickler onions are, unsurprisingly, often pickled.
Onion seed may be “sprouted”, and the resulting sprouts used in salads, sandwiches, and other dishes. (See sprouting.) Onions are available in fresh, frozen, canned, caramelized, pickled, powdered, chopped, and dehydrated forms. Onion powder is a spice used for seasoning in cooking. It is made from finely ground, dehydrated onions, mainly the pungent varieties of bulb onions, which causes the powder to have a very strong odour. Onion powder comes in a few varieties: white, yellow, red and toasted.
Allium sativum, commonly known as garlic, is a species in the onion genus, Allium. Its close relatives include the onion, shallot, leek, chive, andrakkyo. With a history of human use of over 7,000 years, garlic is native to central Asia, and has long been a staple in the Mediterranean region, as well as a frequent seasoning in Asia, Africa, and Europe. It was known to Ancient Egyptians, and has been used for both culinary and medicina purposes. Allium sativum is a bulb. It grows up to 0.5 m (2ft) in height. Its hardiness is USDA Zone 8. It produces hermaphrodite flowers. Pollination occurs by insects and bees.
- Allium sativum var. ophioscorodon (Link) Döll, called Ophioscorodon, or hard necked garlic, includes porcelain garlics, rocambole garlic, and purple stripe garlics. It is sometimes considered to be a separate species, Allium ophioscorodon G.Don.
- Allium sativum var. sativum, or soft-necked garlic, includes artichoke garlic, silverskin garlic, and creole garlic.
Bulb garlic is available in many forms, including fresh, frozen, dried, fermented (black garlic) and shelf stable products (in tubes or jars). In addition, see Culinary uses for other edible parts of the garlic plant.
Garlic is easy to grow and can be grown year-round in mild climates. While sexual propagation of garlic is indeed possible, nearly all of the garlic in cultivation is propagated asexually, by planting individual cloves in the ground. In cold climates, cloves are planted in the fall, about six weeks before the soil freezes, and harvested in late spring. Garlic plants are usually very hardy, and are not attacked by many pests or diseases. Garlic plants are said to repel rabbits and moles. Two of the major pathogens that attack garlic are nematodes and white rot disease, which remain in the soil indefinitely after the ground has become infected. Garlic also can suffer from pink root, a typically nonfatal disease that stunts the roots and turns them pink or red.
Garlic is widely used around the world for its pungent flavor as a seasoning or condiment.
The garlic plant’s bulb is the most commonly used part of the plant. With the exception of the single clove types, garlic bulbs are normally divided into numerous fleshy sections called cloves. Garlic cloves are used for consumption (raw or cooked) or for medicinal purposes. They have a characteristic pungent, spicy flavor that mellows and sweetens considerably with cooking.
Other parts of the garlic plant are also edible. The leaves and flowers (bulbils) on the head (spathe) are sometimes eaten. They are milder in flavor than the bulbs, and are most often consumed while immature and still tender. Immature garlic is sometimes pulled, rather like a scallion, and sold as “green garlic”. When green garlic is allowed to grow past the “scallion” stage, but not permitted to fully mature, it may produce a garlic “round”, a bulb like a boiling onion, but not separated into cloves like a mature bulb. Additionally, the immature flower stalks (scapes) of the hardneck and elephant types are sometimes marketed for uses similar to asparagus in stir-fries.
Inedible or rarely eaten parts of the garlic plant include the “skin” and root cluster. The papery, protective layers of “skin” over various parts of the plant are generally discarded during preparation for most culinary uses, though in Korea immature whole heads are sometimes prepared with the tender skins intact. The root cluster attached to the basal plate of the bulb is the only part not typically considered palatable in any form.
Garlic is a fundamental component in many or most dishes of various regions, including eastern Asia, South Asia, Southeast Asia, the Middle East, northern Africa, southern Europe, and parts of South and Central America. The flavour varies in intensity and aroma with the different cooking methods. It is often paired with onion, tomato, or ginger. The parchment-like skin is much like the skin of an onion, and is typically removed before using in raw or cooked form. An alternative is to cut the top off the bulb, coat the cloves by dribbling olive oil (or other oil-based seasoning) over them, and roast them in an oven. Garlic softens and can be extracted from the cloves by squeezing the (root) end of the bulb, or individually by squeezing one end of the clove. In Korea, heads of garlic are fermented at high temperature; the resulting product, called black garlic, is sweet and syrupy, and is now being sold in theUnited States, United Kingdom and Australia.
Garlic may be applied to different kinds of bread to create a variety of classic dishes, such as garlic bread, garlic toast, bruschetta, crostini and canapé. Oils can be flavored with garlic cloves. These infused oils are used to season all categories of vegetables, meats, breads and pasta. In some cuisines, the young bulbs are pickled for three to six weeks in a mixture of sugar, salt, and spices. In eastern Europe, the shoots are pickled and eaten as an appetizer.
Immature scapes are tender and edible. They are also known as “garlic spears”, “stems”, or “tops”. Scapes generally have a milder taste than the cloves. They are often used in stir frying or braised like asparagus. Garlic leaves are a popular vegetable in many parts of Asia. The leaves are cut, cleaned, and then stir-fried with eggs, meat, or vegetables.
Mixing garlic with egg yolks and olive oil produces aioli. Garlic, oil, and a chunky base produce skordalia. Blending garlic, almond, oil, and soaked bread produces ajoblanco. Garlic powder has a different taste from fresh garlic. If used as a substitute for fresh garlic, 1/8 teaspoon of garlic powder is equivalent to one clove of garlic.
Garlic plants can be grown closely together, leaving enough space for the bulbs to mature, and are easily grown in containers of sufficient depth. When selecting garlic for planting, it is important to pick large heads from which to separate cloves. Large cloves, along with proper spacing in the planting bed, will also improve head size. Garlic plants prefer to grow in a soil with a high organic material content, but are capable of growing in a wide range of soil conditions and pH levels.
There are different types or subspecies of garlic, most notably hardneck garlic and softneck garlic. The latitude where the garlic is grown affects the choice of type as garlic can be day-length sensitive. Hardneck garlic is generally grown in cooler climates; softneck garlic is generally grown closer to the equator. Garlic scapes are removed to focus all the garlic’s energy into bulb growth. The scapes can be eaten raw or cooked.
Garlic has been used as both food and medicine in many cultures for thousands of years, dating at least as far back as when the Giza pyramids were built. Garlic is still grown in Egypt, but the Syrian variety is the kind most esteemed now (see Rawlinson‘s Herodotus, 2.125). Hippocrates, Galen, Pliny the Elder, and Dioscorides all mention the use of garlic for many conditions, including parasites, respiratory problems, poor digestion, and low energy. Its use in China dates back to 2000 BCE. It was consumed by ancient Greek and Roman soldiers, sailors, and rural classes (Virgil, Ecologues ii. 11), and, according to Pliny the Elder (Natural History xix. 32), by the African peasantry. Galen eulogizes it as the “rustic’s theriac” (cure-all) (see F. Adams’ Paulus Aegineta, p. 99), and Alexander Neckam, a writer of the 12th century (see Wright’s edition of his works, p. 473, 1863), recommends it as a palliative for the heat of the sun in field labor.
In the account of Korea’s establishment as a nation, a tiger and a bear prayed to Hwanung that they may become human. Upon hearing their prayers, Hwanung gave them 20 cloves of garlic and a bundle of mugwort, ordering them to eat only this sacred food and remain out of the sunlight for 100 days. The tiger gave up after about twenty days and left the cave. However, the bear remained and was transformed into a woman.
In in vitro studies, garlic has been found to have antibacterial, antiviral, and antifungal activity. However, these actions are less clear in vivo. Garlic is also claimed to help prevent heart disease (includingatherosclerosis, high cholesterol, and high blood pressure) and cancer. Garlic is used to prevent certain types of cancer, including stomach and colon cancers. Animal studies, and some early research studies in humans, have suggested possible cardiovascular benefits of garlic. A Czech study found garlic supplementation reduced accumulation of cholesterol on the vascular walls of animals. Another study had similar results, with garlic supplementation significantly reducing aortic plaque deposits of cholesterol-fed rabbits. Another study showed supplementation with garlic extract inhibited vascular calcification in human patients with high blood cholesterol.