Thursday, April 21, 2011

Superfood: Ginger

Ginger is a tuber that is consumed whole as a delicacy, medicine, or spice. It is the rhizome of the plant Zingiber officinale. It lends its name to its genus and family (Zingiberaceae). Other notable members of this plant family are turmeric, cardamom, and galangal.
Ginger cultivation began in South Asia and has since spread to East Africa and the Caribbean. It is sometimes called root ginger to distinguish it from other things that share the name ginger.
The English name ginger comes from French: gingembre, Old English: gingifere, Medieval Latin: ginginer.
The characteristic odor and flavor of ginger is caused by a mixture of zingerone, shogaols and gingerols, volatile oils that compose one to three percent of the weight of fresh ginger. In laboratory animals, the gingerrols increase the motility of the gastrointestinal tract and have analgesic, sedative, antipyretic and antibacterial properties. Ginger oil has been shown to prevent skin cancer in mice and a study at the University of Michigan demonstrated that gingerols can kill ovarian cancer cells.
Ginger contains up to three percent of a fragrant essential oil whose main constituents are sesquiterpenoids, with (-)-zingiberene as the main component. Smaller amounts of other sesquiterpenoids (β-sesquiphellandrene, bisabolene and farnesene) and a small monoterpenoid fraction (β-phelladrene, cineol, and citral) have also been identified.
The pungent taste of ginger is due to nonvolatile phenylpropanoid-derived compounds, particularly gingerols and shogaols, which form from gingerols when ginger is dried or cooked. Zingerone is also produced from gingerols during this process; this compound is less pungent and has a spicy-sweet aroma. Ginger is also a minor chemical irritant, and because of this was used as a horse suppository by pre-World War I mounted regiments for feaguing.
Ginger has a sialagogue action, stimulating the production of saliva, which makes swallowing easier.
Culinary Use
Young ginger rhizomes are juicy and fleshy with a very mild taste. They are often pickled in vinegar or sherry as a snack or just cooked as an ingredient in many dishes. They can also be steeped in boiling water to make ginger tea, to which honey is often added; sliced orange or lemon fruit may also be added. Ginger can also be made into candy.
Mature ginger roots are fibrous and nearly dry. The juice from old ginger roots is extremely potent, and is often used as a spice in Indian recipes, and is a quintessential ingredient of Chinese, Japanese and many South Asian cuisines for flavoring dishes such as seafood or goat meat and vegetarian cuisine. Ginger acts as a useful food preservative.
Fresh ginger can be substituted for ground ginger at a ratio of 6 to 1, although the flavors of fresh and dried ginger are somewhat different. Powdered dry ginger root is typically used as a flavoring for recipes such as gingerbread, cookies, crackers and cakes, ginger ale, and ginger beer. Candied ginger is the root cooked in sugar until soft, and is a type of confectionery.
Fresh ginger may be peeled before eating. For longer-term storage, the ginger can be placed in a plastic bag and refrigerated or frozen.
Regional Use
In India, ginger is called Aadrak. Fresh ginger is one of the main spices used for making pulse and lentil curries and other vegetable preparations. Fresh, as well as dried, ginger is used to spice tea and coffee, especially in winter. Ginger powder is also used in certain food preparations, particularly for pregnant or nursing women, the most popular one being Katlu which is a mixture of gum resin, ghee, nuts, and sugar. Ginger is also consumed in candied and pickled form.
In Bangladesh, ginger is called Aadha and is finely chopped or ground into a paste to use as a base for chicken and meat dishes alongside shallot and garlic.
In the Philippines, ginger is called luya and is used as "candy" when there is sore throat or hoarse voice.
In Burma, ginger is called gyin. It is widely used in cooking and as a main ingredient in traditional medicines. It is also consumed as a salad dish called gyin-thot, which consists of shredded ginger preserved in oil, and a variety of nuts and seeds.
In Indonesia, a beverage called wedang jahe is made from ginger and palm sugar. Indonesians also use ground ginger root, called jahe, as a common ingredient in local recipes.
In Nepal, ginger is called "aduwa" and is widely grown and used throughout the country as a spice for vegetables, used medically to treat cold and also sometimes used to flavor tea.
In Vietnam, the fresh leaves, finely chopped, can also be added to shrimp-and-yam soup as a top garnish and spice to add a much subtler flavor of ginger than the chopped root.
In China, sliced or whole ginger root is often paired with savory dishes such as fish, and chopped ginger root is commonly paired with meat, when it is cooked. However, candied ginger is sometimes a component of Chinese candy boxes, and a herbal tea can also be prepared from ginger.
In Japan, ginger is pickled to make beni shoga and gari or grated and used raw on tofu or noodles. It is also made into a candy called shoga no satozuke.
In the traditional Korean kimchi, ginger is finely minced and added to the ingredients of the spicy paste just before the fermenting process.
In Western cuisine, ginger is traditionally used mainly in sweet foods such as ginger ale, gingerbread, ginger snaps, parkin, ginger biscuits and speculaas. A ginger-flavored liqueur called Canton is produced in Jarnac, France. Green ginger wine is a ginger-flavored wine produced in the United Kingdom, traditionally sold in a green glass bottle. Ginger is also used as a spice added to hot coffee and tea.
In the Caribbean, ginger is a popular spice for cooking, and making drinks such as sorrel, a seasonal drink made during the Christmas season. Jamaicans make ginger beer both as a carbonated beverage and also fresh in their homes. Ginger tea is often made from fresh ginger, as well as the famous regional specialty Jamaican ginger cake.
On the island of Corfu, Greece, a traditional drink called tsitsibira, a type of ginger beer, is made. The people of Corfu and the rest of the Ionian islands adopted the drink from the British, during the period of the United States of the Ionian Islands.
In Arabic, ginger is called zanjabil, and in some parts of the Middle East, ginger powder is used as a spice for coffee and for milk, as well. In Somaliland, ginger is called sinjibil, and is served in coffee shops in Egypt.
In the Ivory Coast, ginger is ground and mixed with orange, pineapple and lemon to produce a juice called nyamanku.
Medicinal use
The medical form of ginger historically was called Jamaica ginger; it was classified as a stimulant and carminative and used frequently for dyspepsia, gastroparesis, slow motility symptoms, constipation, and colic. It was also frequently employed to disguise the taste of medicines. Ginger is on the FDA's "generally recognized as safe" list, though it does interact with some medications, including warfarin. Ginger is contraindicated in people suffering from gallstones as it promotes the production of bile. Ginger may also decrease pain from arthritis, though studies have been inconsistent, and may have blood thinning and cholesterol lowering properties that may make it useful for treating heart disease. An acute overdose of ginger is usually in excess of about 2,000 milligrams per kilogram, dependent on level of ginger tolerance, and can result in a state of central nervous system over-stimulation called ginger intoxication or colloquially the "ginger gitters".
Ginger compounds are active against a form of diarrhea which is the leading cause of infant death in developing countries. Zingerone is likely to be the active constituent against enterotoxigenic Escherichia coli heat-labile enterotoxin-induced diarrhea.
Ginger has been found effective in multiple studies for treating nausea caused by seasickness, morning sickness and chemotherapy, though ginger was not found superior over a placebo for pre-emptively treating post-operative nausea. Ginger is a safe remedy for nausea relief during pregnancy. Ginger as a remedy for motion sickness is still a debated issue. The television program Mythbusters performed an experiment using one of their staff who suffered from severe motion sickness. The staff member was placed in a moving device which, without treatment, produced severe nausea. Multiple treatments were administered. None, with the exception of the ginger and the two most common drugs, were successful. The staff member preferred the ginger due to lack of side effects. Several studies over the last 20 years were inconclusive with some studies in favor of the herb and some not. A common thread in these studies is the lack of sufficient participants to yield statistical significance. Another issue is the lack of a known chemical pathway for the supposed relief.
Folk medicine
A variety of uses are suggested for ginger. Tea brewed from ginger is a folk remedy for colds. Three to four leaves of tulsi taken with a piece of ginger on an empty stomach is considered an effective cure for congestion, cough and cold. Ginger ale and ginger beer have been recommended as stomach settlers for generations in countries where the beverages are made, and ginger water was commonly used to avoid heat cramps in the United States. In China, "ginger eggs" (scrambled eggs with finely diced ginger root) is a common home remedy for coughing. The Chinese also make a kind of dried ginger candy that is fermented in plum juice and sugared, which is also commonly consumed to suppress coughing. Ginger has also been historically used to treat inflammation, which several scientific studies support, though one arthritis trial showed ginger to be no better than a placebo or ibuprofen for treatment of osteoarthritis. Research on rats suggests that ginger may be useful for treating diabetes.
Regional medicinal use
The West, powdered dried ginger root is made into capsules and sold in pharmacies for medicinal use.
  • In Burma, ginger and a local sweetener made from palm tree juice (htan nyat) are boiled together and taken to prevent the flu.
  • In China, ginger is included in several traditional preparations. A drink made with sliced ginger cooked in water with brown sugar or a cola is used as a folk medicine for the common cold.
  • In Congo, ginger is crushed and mixed with mango tree sap to make tangawisi juice, which is considered a panacea.
  • In India, ginger is applied as a paste to the temples to relieve headache, and consumed when suffering from the common cold. Ginger with lemon and black salt is also used for nausea.
  • In Indonesia, ginger ("jahe" in Indonesian) is used as a herbal preparation to reduce fatigue, reducing "winds" in the blood, prevent and cure rheumatism and control poor dietary habits.
  • In the Philippines a traditional health drink called "salabat" is made for breakfast by boiling chopped ginger and adding sugar; it is considered good for a sore throat.
  • In the United States, ginger is used to prevent motion and morning sickness. It is recognized as safe by the Food and Drug Administration and is sold as an unregulated dietary supplement.
  • In Peru, ginger is sliced in hot water as an infusion for stomach aches as "infusión de Kión"
Allergic reactions to ginger generally result in a rash, and although generally recognized as safe, ginger can cause heartburn, bloating, gas, belching and nausea, particularly if taken in powdered form. Un-chewed fresh ginger may result in intestinal blockage, and individuals who have had ulcers, inflammatory bowel disease or blocked intestines may react badly to large quantities of fresh ginger. Ginger can also adversely affect individuals with gallstones. There are also suggestions that ginger may affect blood pressure, clotting, and heart rhythms.


Superfood: Onion

The onion is any of a variety of plants in the genus Allium, specifically Allium cepa. Allium cepa is also known as the "garden onion" or "bulb" onion. Above ground, the onion shows only a single vertical shoot; the bulb grows underground, and is used for energy storage, leading to the possibility of confusion with a tuber, which it is not. It is a close relative to garlic.
Allium cepa is known only 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. vavilovii collections tested represent genuine wild material or only feral derivatives of the crop.”
Onions are found in a large number of recipes and preparations spanning almost the totality of the world's cultures. The whole plant is edible and is used as food in some form or the other. They are now available in fresh, frozen, canned, caramelized, pickled, powdered, chopped, and dehydrated forms. Onions can be used, usually chopped or sliced, in almost every type of food, including cooked foods and fresh salads and as a spicy garnish. In European cultures they are rarely eaten on their own, but usually act as accompaniment to the main course. Depending on the variety, an onion can be sharp, spicy, tangy, and pungent or mild and sweet.
Onions pickled in vinegar are eaten as a snack. These are often served as a side serving in fish and chip shops throughout Australia, often served with cheese in the United Kingdom and are referred to simply as "pickled onions" in Eastern Europe. Onions are widely used in Iran and India and Pakistan, and are essential to daily life in the local cuisine. They are commonly used as a base for curries or made into a paste and eaten as a main course or as a side dish.
Onions are also used as an aromatic in cooking. In the classic mirepoix it is used along with celery and carrots to flavor stocks, soups, stews and sauces.
Onions have particularly large cells that are readily observed at low magnification; consequently, onion tissue is frequently used in science education for demonstrating microscope usage.
Possible medicinal properties and health effects of onions
In many parts of the world, onions are used to heal blisters and boils. A traditional Maltese remedy for sea urchin wounds is to tie half a baked onion to the afflicted area overnight. An application of raw onion is also said to be helpful in reducing swelling from bee stings. In the United States, products that contain onion extract are used in the treatment of topical scars; some studies have found their action to be ineffective, while others found that they may act as an anti-inflammatory or bacteriostatic and can improve collagen organization in rabbits.

Wide-ranging claims have been made for the effectiveness of onions against conditions ranging from the common cold to heart disease, diabetes, osteoporosis, and other diseases. They contain chemical compounds believed to have anti-inflammatory, anticholesterol, anticancer, and antioxidant properties such as quercetin. However, it has not been conclusively demonstrated that increased consumption of onions is directly linked to health benefits. Some studies have shown that increased consumption of onions reduces the risk of head and neck cancers. In India some sects do not eat onion due to its alleged aphrodisiac properties. Many also believe that eating onions can lead to weight loss. However, this claim has never been substantiated.
Onions may be especially beneficial for women, who are at increased risk for osteoporosis as they go through menopause, by destroying osteoclasts so that they do not break down bone.
An American chemist has stated that the pleiomeric chemicals in onions have the potential to alleviate or prevent sore throat. Onion in combination with jaggery has been widely used as a traditional household remedy for sore throat in India.
Shallots have the most phenols, six times the amount found in Vidalia onion, the variety with the lowest phenolic content. Shallots also have the most antioxidant activity, followed by Western Yellow, pungent yellow (New York Bold), Northern Red, Mexico, Empire Sweet, Western White, Peruvian Sweet, Texas 1015, Imperial Valley Sweet, and Vidalia. Western Yellow onions have the most flavonoids, eleven times the amount found in Western White, the variety with the lowest flavonoid content.
For all varieties of onions, the more phenols and flavonoids they contain, the more reputed antioxidant and anti-cancer activity they provide. When tested against liver and colon cancer cells, 'Western Yellow' pungent yellow (New York Bold) and shallots were most effective in inhibiting their growth. The milder-tasting cultivars (i.e., 'Western White,' 'Peruvian Sweet,' 'Empire Sweet,' 'Mexico,' 'Texas 1015,' 'Imperial Valley Sweet,' and 'Vidalia') showed little cancer-fighting ability.
Shallots and ten other onion (Allium cepa L.) varieties commonly available in the United States were evaluated: Western Yellow, Northern Red, pungent yellow (New York Bold), Western White, Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial Valley Sweet, and Vidalia. In general, the most pungent onions delivered many times the benefits of their milder cousins.
3-mercapto-2-methylpentan-1-ol in onion was found to have an antioxidant potent that inhibits peroxynitrite induced diseases.
Eye irritation
As onions are sliced or eaten, cells are broken, allowing enzymes called alliinases to break down amino acid sulphoxides and generate sulphenic acids. A specific sulfenic acid, 1-propenesulfenic acid, formed when onions are cut, is rapidly rearranged by a second enzyme, called the lachrymatory factor synthase or LFS, giving syn-propanethial-S-oxide, a volatile gas known as the onion lachrymatory factor or LF. The LF gas diffuses through the air and eventually reaches the eye, where it activates sensory neurons, creating a stinging sensation. Tear glands produce tears to dilute and flush out the irritant (Chemicals that exhibit such an effect on the eyes are known as lachrymatory agents).
Supplying ample water to the reaction while peeling onions prevents the gas from reaching the eyes. Eye irritation can, therefore, be avoided by cutting onions under running water or submerged in a basin of water. Another way to reduce irritation is by chilling, or by not cutting off the root of the onion (or by doing it last), as the root of the onion has a higher concentration of enzymes. Using a sharp blade to chop onions will limit the cell damage and the release of enzymes that drive the irritation response. Chilling or freezing onions prevents the enzymes from activating, limiting the amount of gas generated. Eye irritation can also be avoided by having a fan blow the gas away from the eyes as the onion is being cut.
It is also possible to avoid eye irritation by wearing goggles or any eye protection that creates a seal around the eye. Contact lens wearers can experience less immediate irritation as a result of the slight protection afforded by the lenses themselves. It may also be that lens wearers are familiar with controlling the more reflexive actions of their eyes with regards to irritation, to prevent blinking, as this is an ability they require when manipulating the lenses.
The amount of sulfenic acids and LF released, and the irritation effect, differs among Allium species. On January 31, 2008, the New Zealand Crop and Food institute created a strain of "no tears" onions by using gene-silencing biotechnology to prevent synthesis by the onions of the lachrymatory factor synthase enzyme.
Green onion and leeks are optimally stored refrigerated. Cooking onions and sweet onions, on the other hand, can be stored at room temperature, optimally in a single layer, in mesh bag in a dry, cool, dark, well ventilated location. In this environment, cooking onions have a shelf life of 3 to 4 weeks, and sweet onions 1 to 2 weeks. Cooking onions will absorb odours from apples and pears. Also, they draw moisture from vegetables they are stored with which may cause them to decay. Sweet onions have a greater water and sugar content than cooking onions. This makes them sweeter and milder tasting, but also reduces their shelf life. Sweet onions can also be stored refrigerated, where they have a shelf life of approximately 1 month, optimally uncovered. Irrespective of type, any cut pieces of onion are optimally tightly wrapped, stored away from other produce, and used within 2 to 3 days.