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The Onion is a worldwide culinary and therapeutic spice used daily and in nearly every meal across Africa. This spice needs no special introduction as it is one of the most known spices in the world. Unfortunately, a lot of us use without knowing the numerous nutritional benefits of onions. Well, this article is out to address that.
Onion is a common component in many African sauces, and it is mainly grown locally, with Egypt being the continent’s first producer. Onions include phenolic acids, thiosulfinates, and flavonoids, among other biologically active chemicals.
Anticancer, antidiabetic, antibacterial, cardiovascular, antioxidant, and other pharmacological actions of the plant indicate its potential application in the treatment of a number of human disorders. Onion, also known as the bulb onion or common onion is a vegetable. It has narrow, hollow leaves and a base which enlarges to form a bulb. The bulb can be white, yellow, or red and require 80 to 150 days to reach harvest. Its close relatives include garlic, scallion, leek, chive, and Chinese onion.
For at least 7,000 years, the onion plant has been cultivated and selectively bred. Although it is biannual, it is commonly grown as an annual. Modern cultivars usually reach a height of 15 to 45 cm (6 to 18 in). The leaves are yellowish to bluish green and grow in a flattened, fan-shaped swath alternately. They have one flattened side and are soft, hollow, and cylindrical.
They are at their broadest approximately a quarter of the way up, before tapering to a blunt point.
Each leaf’s base is a flattened, typically white sheath that emerges from the bulb’s basal plate. A bundle of fibrous roots extends a short distance into the earth from the plate’s underside. Food reserves begin to develop in the leaf bases as the onion matures, and the onion bulb swells.
The leaves die back in the autumn, and the outer scales of the bulb become dry and brittle, thus the crop is usually harvested then. The growth point in the middle of the bulb begins to develop in the spring if it is left in the soil during the winter.
New leaves emerge, and a tall, sturdy, hollow stem with a bract sheltering a budding inflorescence expands. The inflorescence is a globular umbel of white flowers divided into six segments. The seeds are glossy black in color and triangular in shape. An onion’s pH is usually around 5.5.
History of onions
Because the wild onion is extinct and ancient records of using onions span western and eastern Asia, the geographic origin of the onion is uncertain, although domestication likely took place in Southwest or Central Asia. Onions have been variously described as having originated in Iran, western Pakistan, and Central Asia.
Onions were utilized as far back as 5000 BC, according to traces found in Bronze Age towns in China, not only for their flavor but also for the bulb’s resilience in storage and transportation.
The onion bulb was treasured by ancient Egyptians, who saw its spherical shape and concentric rings as symbols of an endless life.
Onions were utilized in Egyptian funerals, as demonstrated by onion remnants discovered in Ramesses IV’s eye sockets.
Pliny the Elder of the first century AD wrote about the use of onions and cabbage in Pompeii. He detailed Roman believes in the onion’s power to treat anything from mouth ulcers and toothaches to dog bites, lumbago, and even dysentery. Garden like those described in Pliny’s precise tales has been discovered by archaeologists digging Pompeii long after its 79 AD volcanic burial.
Onions were employed in several Roman recipes, according to documents collected in the fifth/sixth centuries AD under the authorial auspices of “Apicius” (supposed to be a gourmet). Onions were brought to North America by the first European settlers during the Age of Discovery, only to discover that the plant was freely available and widely used in Native American cuisine. The bulb onion was one of the earliest crops planted by the Pilgrim fathers, according to diaries written by some of the first English immigrants.
Onion production in Africa
Egypt is the 3rd largest onion producer in the world, producing more than 2.3 million tons per year. According to the Egyptian Ministry of Agriculture and Land Reclamation, onion exports from Egypt increased by about 45 percent in 2019 compared to 2018. On November 27th, onion exports totaled 550 thousand tons, up from 310 thousand tons the previous year.
The major buyer of the crop was Saudi Arabia, but Egypt depended on new markets this season, including India, Pakistan, Bangladesh, and other Asian countries, to dramatically increase exports.
Onions are one of West Africa’s most dynamic regional sectors. Senegal’s production has surged tenfold in ten years, reaching 400,000 tons. Nigeria and Niger are the region’s top producers, producing 600,000 and 500,000 tons respectively.
Nigeria is one of the major producers of onions in the world, producing more than 2 million tonnes yearly. Red onion is the most popular variety in Nigeria and is of immense benefit to commercial onion farmers due to their wide patronage. In Nigeria, onion is grown mostly in Kano, Kaduna, Jigawa, Sokoto, Plateau, Bauchi, and Kebbi States. In 2012 alone, an estimate of about 240,000 tons of green onions and 1,350,000 tons of dry onions were produced in Nigeria.
In Nigeria, Sokoto happens to be the largest producer of onion. From April to August 2020, onions worth four billion were sold despite the fact that Aliero village in Kebbi State, has the biggest onion farm/market in West Africa and buyers come from neighboring countries such as Cotonou, Togo, Ghana, etc to buy.
The people of Aliero pride themselves as the largest onion farming community in West Africa, not just because they get high patronage from other onion traders in the Southern, Eastern and other Northern parts of Nigeria, but also because they export their commodity to neighboring countries such as Benin Republic, Niger, and Cameroon.
Different types of onions
The main differences between onions are determined by the time of year and the location in which they are grown, which might influence their flavor. Spring onions, for example, are grown in warmer areas and have a milder, sweeter flavor.
Here are different types of onions to familiarize yourself with:
1. Red onions
Red onions are cultivars of the onion and have purplish-red skin and white flesh tinged with red. The skin of the red onion has been employed as a dye in the past, but it is most typically used in the culinary arts. These onions are medium to large in size, with a strong flavor and a mouthwatering appearance.
They’re commonly eaten raw (adding color and bite to salads), grilled, or lightly cooked with other meals. Red onions are accessible all year and include a lot of flavonoids and fiber (compared to white and yellow onions). Cut red onion can be soaked in cool water for a short time and then drained, resulting in a reduction in “bite” and pungency.
2. Sweet onions
Sweet onion is a non-pungent kind of onion. When compared to other onion cultivars, its mildness is due to its low sulfur level and high water content. They can range in color from white to yellow and often have a flattened or squashed appearance.
Sweet onions tend to be more perishable and should be stored in the refrigerator. The best way to preserve sweet onions and to prevent bruising is to store them in a cool, dry place and separated from each other. Always handle sweet onions carefully. Wrap sweet onions separately in paper towels or newspaper and store them in the refrigerator.
Whole raw sweet onions will last for 1 to 2 months in a cool (45-55° F; warmer than the refrigerator, but colder than normal room temperature) dark area. If a cool, dark area is not available, then sweet onions should be refrigerated to ensure maximum shelf life.
3. Green onion (Scallions)
Green onions (mostly known as scallions, spring onions, or sibies) are vegetables that come from the Allium genus. The flavor of scallions is milder than that of most onions. Garlic, shallot, leek, chive, and Chinese onions are close relatives.
These onions are frequently plucked before they reach full maturity. Both in appearance and flavor, these baby or immature onions differ from bulbing onions. Green onions have long green tips and a sleek linear shape with white or pale-green bulbs. The bulb and stem are both tasty.
Types of green onions
Although the bulbs of many Allium species are eaten, spring onion species are distinguished by the absence of a completely grown bulb. Spring onions are Allium species with hollow, tubular green leaves that sprout directly from the bulb. These leaves are eaten raw or cooked and are used as a vegetable. The leaves are frequently sliced into other recipes in the same way that onions or garlic are chopped into other cuisines.
Chives are a little green herb with a slight onion flavor. They belong to the Allium genus, which contains garlic, onions, and leeks, among others. For millennia, people have grown allium vegetables for their distinctive pungent aromas in culinary and medicinal benefits.
Allium schoenoprasum, or chives, provide elements that are beneficial to sleep and bone health. Chemicals found in chives and other allium plants have also been related to anticancer properties in some studies.
Leeks are a member of the onion family, native to the eastern Mediterranean and the Middle East—the biggest producers are Indonesia, Turkey, France, Republic of Korea, and Belgium. Leeks look like scallions (or green onions), but they’re a lot larger. And their mild flavor and ease of preparation make the vegetable a favorite addition to soups, casseroles, and white meat entrées, as well as a simple side dish when gently sautéed. Look for the best leeks of the year starting in autumn and enjoy them all the way through spring.
4. Pearl onion
White Pearl onions are globular in shape with slightly pointed ends and are tiny in size, usually 1-4 cm in diameter. The tiny bulb is wrapped in a thin, papery layer of white parchment that easily peels away when touched. A white sheath, similar to garlic, lies beneath the papery epidermis, and the flesh is white, nearly translucent, with layers of thin rings. It has a firm, juicy, and crisp texture. When cooked, white pearl onions become crunchy and mild, with a savory, sweet, and slightly less pungent flavor than full-sized onions.
5. Egyptian onion
Tree onions, also known as topsetting onions, walking onions, or Egyptian onions, are identical to common onions (Allium cepa) but feature a cluster of bulblets instead of blooms. They are a hybrid of the common onion and the Welsh onion, according to genomic data (A. fistulosum). Some sources, however, continue to refer to the tree onion as A. cepa var. proliferum or A. cepa Proliferum Group. While still attached to the parent stalk, tree onion bulblets will sprout and grow. The name “walking onion” comes from the fact that they may bend down under the weight of new growth and take root at a distance from the parent plant.
It has been postulated that the name “Egyptian onion” derived from Romani people bringing tree onions to Europe from the Indian subcontinent.
Shallots, like garlic, grow in clusters of offsets with a head made up of many cloves. Shallots’ skin can be golden brown, gray, or rose red, and its off-white flesh is generally colored with green or magenta.
Shallots are a type of onion that is used in cooking. It’s possible that they’ll be pickled. In Asian cuisine, finely sliced deep-fried shallots are commonly served with porridge as a condiment. Shallots, as a species of Allium, have a flavor similar to that of a regular onion, but with a milder flavor. When raw shallots are sliced, they release chemicals that irritate the human eye, causing tears to be produced.
7. Yellow onion
The brown onion or yellow onion (Allium cepa L.) is a variety of dry onions with a strong flavor. They have a greenish-white, light yellow, or white inside; their layers of papery skin have a yellow-brown or pale golden color.
It is higher in sulfur content than the white onion which gives it a stronger, more complex flavor.
A dozen varieties of yellow onion are grown, following the time of year. They vary in nutritional content, but they do contain quercetin (a flavanol).
Fun facts about onions
- Onions have been a part of the human diet for more than 7,000 years. Archeologists have discovered traces of onions dating back to 5000 B.C., found alongside stones from figs and dates in settlements from the Bronze Age.
- On almost every continent, wild onions can be found. Because onions are one of the few vegetables that can be easily kept for the winter, their popularity expanded along with them all over the world.
- In ancient Egypt, onions were worshiped. It was believed by ancient Egyptians that concentric rings and the spherical shape of the onions were symbols of eternity.
- Onions were used as gifts and even payment during the Middle Ages. Onions were once used to pay for services, commodities, and even rent.
- The sulfuric acid created in our eyes causes a stinging sensation, prompting the brain to react. Our brain, in a defensive attitude, causes our eyes to generate tears, which wash away the acid. Crying while cutting onions is what we call it.
- The Guinness Book of World Records lists the largest onion ever grown as a whopping 10 pound, 14-ounce onion!
- Did you know that Libyans are known for their onion consumption? Libyans consume a remarkable 66.8 pounds of onions per year per capita.
Nutritional values of onions
Raw onions have a low-calorie content, with only 40 calories per 3.5 ounces (100 grams). They are 89 percent water, 9 percent carbohydrates, and 1.7 percent fiber by fresh weight, with trace amounts of protein and fat.
The main nutrients in 3.5 ounces (100 grams) of raw onions are:
- Calories: 40
- Water: 89%
- Protein: 1 gram
- Carbs: 3 grams
- Sugar: 2 grams
- Fiber: 7 grams
- Fat: 1 gram
Carbohydrates account for 9–10% of raw and cooked onions, respectively. Simple sugars like glucose, fructose, and sucrose, as well as fiber, make up the majority of their composition. The total digestible carb value of a 3.5-ounce (100-gram) piece is 7.6 grams, including 9.3 grams of carbs and 1.7 grams of fiber.
Onions are a good source of fiber, accounting for approximately 0.9–2.6 percent of the fresh weight depending on the variety. They’re high in fructans, which are beneficial soluble fibers. Onions are one of the most common sources of fructans in the diet. Fructans are prebiotic fibers that nourish the good microorganisms in your intestine. Short-chain fatty acids (SCFAs), such as butyrate, are formed as a result of this, which may improve colon health, reduce inflammation, and lower your risk of colon cancer.
FODMAPs, on the other hand, are fructans, which can induce unpleasant digestive symptoms in people who are sensitive to them, such as those who have irritable bowel syndrome (IBS).
Onions contain decent amounts of several vitamins and minerals, including:
- Vitamin C: An antioxidant, this vitamin is needed for immune function and maintenance of skin and hair.
- Folate (B9): A water-soluble B vitamin, folate is essential for cell growth and metabolism and especially important for pregnant women.
- Vitamin B6: Found in most foods, this vitamin is involved in the formation of red blood cells.
- Potassium: This essential mineral can have blood-pressure-lowering effects and is important for heart health.
Eating onions raw vs cooked
Onions have vital therapeutic and nutritional properties, and they were even utilized in ancient times to combat cholera and the plague. Natural sugar, vitamins A, B6, C, and E, sodium, potassium, iron, dietary fiber, and folic acid are all found in onions. However, heat destroys some of these health benefits, so if you want to get the most out of your onion, you’ll have to consume it raw.
Health benefits of onions
1. Lowers risk of heart diseases and stroke:
Organic sulfur compounds can be found in onions. These chemicals are responsible for onions’ harsh, pungent flavor and odor. Organic sulfur compounds lower the risk of heart disease and stroke by decreasing cholesterol levels in your body and maybe breaking down blood clots. To acquire the most sulfur compounds from onions, eat them raw rather than cooked.
2. Improves the body’s immunity:
These days, everything revolves around immunity. Onions include antioxidants that can help you strengthen this as well. According to a study published in the journal Mediators of Inflammation, the chemical makeup of onions is so powerful that it aids in immunological boosting and also has anti-cancer capabilities.
3. Onions can be great for the eyes:
The selenium in onion helps in the production of vitamin E, which in turn keeps this painful eye problem at bay. In fact, some natural eye drops also contain extracts of onion juice.
4. It contains cancer-fighting compounds:
Garlic and onions, which belong to the Allium genus, have been related to a lower risk of some malignancies, particularly stomach and colorectal cancers. Studies have shown that people who consume higher amounts of allium vegetables are 22% less likely to be diagnosed with stomach cancer than those who consume less amount.
5. It improves libido in men
If your boyfriend suffers from erectile dysfunction, force him to consume onions, which, according to a study published in the journal Biomolecules, can help to alleviate the problem. According to the study, it also aids in the increase of testosterone levels in men.
6. It lowers the risk of Alzheimer’s disease:
Flavonoids are plant-derived compounds that are abundant in onions. According to one study, those who eat a high-flavonoid diet for a long time have a lower risk of Alzheimer’s disease.
7. It is good for bone health:
Incorporating onions into one’s diet has been linked to increased bone density. This could be due to their antioxidant qualities, which help to prevent oxidative stress and bone loss. According to a study including peri- and postmenopausal women, frequent onion eating reduced the incidence of hip fracture. Another study on middle-aged women found that drinking onion juice decreased bone loss and increased bone density.
8. It may support gut health:
Onions are high in fiber, especially non-digestible fiber, which is important for intestinal health. Although we cannot digest prebiotic fiber, the bacteria that live in our gut can, and they use it as fuel to help them grow and create short-chain fatty acids as by-products (SCFAs). These SCFAs are vital for gut health and integrity, as well as aiding our immune and digestion, according to research.
9. It helps in the control and management of diabetes:
Both the quercetin and organic sulfur compounds found in onions are known to promote insulin production, making them a helpful vegetable choice for those with diabetes.
10. It helps relieve cough and cold:
Onions are used in folk medicine to treat coughs, colds, and catarrh, and studies show that they have antibacterial properties against bacteria like E. coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Furthermore, it appears that older, preserved onions are the most effective. Quercetin appears to be useful here once again, as it inhibits the growth of Helicobacter pylori and Methicillin-resistant Staphylococcus aureus (MRSA).