Botanical name: Allium cepa
The onion is one of those vegetables that no garden should be without: it is versatile, almost indispensable in the kitchen and keeps various plant parasites away, also contributing to a better growth of other plant species, for which intercropping is recommended. Onion has numerous properties useful for health: it helps regulate blood pressure and promotes diuresis. The consumption of this vegetable is also recommended in diets because it has a low calorie content but is rich in minerals. Growing the onion requires little effort, the plant and the umbrella buds have a pleasant appearance and you can choose from a large number of varieties and uses in the kitchen.
As for all bulbous plants, also for Onions, and especially for certain varieties, it is possible to use "Bulbilli" instead of seeds, ie those Bulbs, obtained from seeds on spring crops specially sown dense.
These Bulbs, uprooted when they have a diameter of just under 2 cm, ventilated at an appropriate temperature (4 - 8° C) so that they do not germinate, they are planted (in the same way as for transplanting seedlings in seedbeds) by October to March, to obtain an early production.
Origins and history
Consumed and widespread all over the world, traces of the onion (probably related to a species of wild onion) have been found in the region between Lebanon and Jordan dating back to 5,000 B.C.. The actual cultivation of onion however began - together with that of garlic and leek - around 3,000 B.C. in Egypt, from where migrations and trade have spread it to the rest of Europe.
In America this bulbous of the Liliaceae - the most recent classification attributes it to the Amaryllidaceae - was introduced by Christopher Columbus in 1493. The popularity of the onion has always been very great, due to the yield in cultivation, the multiplicity of uses and the ease of transport; Greeks and Romans consumed it in abundance, while Charlemagne in his "Capitulare de villis" - a decree which regulated agricultural activities among other things - recommended its cultivation.
Among the Egyptians it was believed that its pungent smell could make the dead breathe, while the spherical shape of the bulbs and the internal concentric layers were seen as symbols of eternal life.
Nutritional and beneficial properties of the onion
Very low in calories (20-26 per 100 grams), onion is rich in water, vitamins (A, B, C, E) and mineral salts, among which potassium (which helps against rheumatism) and silicon, a mineral that stimulates calcium to stick to the bones.
Also contains quercetin, an antioxidant that helps fight inflammation. Its ability to assist in diuresis, protect the prostate and decrease the risk of infections has also been demonstrated.
The only negative note of the onion is the characteristic strong smell, due to the sulfur compounds contained in the plant, elements that make the eyes water when it is cut. However, it is sufficient to pass it under water to eliminate most of the sulfur compounds.
Onion use in cooking and benefits
The infinite qualities of this vegetable vary in color (white onions, yellow onions or red onions), shape, size, flavor and its use in cooking. For example, the so-called sweet onion is milky white, much less acrid than other types thanks to a lower sulfur content and a greater quantity of water, suitable for delicate or canned creams. The common golden type - with a not too marked taste - is perfect for sautéed, while the red onion is excellent raw in salads with tomatoes or beans.
In addition to being a base for the mince, the onion can also be used as the main ingredient of the typical French soup, au gratin and served with croutons. The golden or white onions are finely sliced and cooked very slowly in the beef broth, until the soup gives its sweetness and gives it its characteristic brown color. The dish is served by pouring the soup over slices of rustic bread on top of which gruyere is browned.
Another unusual and interesting recipe that uses onion is that of jam, to be served with boiled or roasted meats and aged cheeses, for a surprising and tasty contrast. It is preferably prepared with red Tropea onions, sugar, a little vinegar and salt and one or two bay leaves per jar. Onions can be used to fill a savory pie with shortcrust pastry or phyllo dough, for example together with cherry tomatoes, olives and aromatic herbs.
Curiosities about onions
Scientific nomenclature calls the onion "Allium cepa", and the word "cepa" meant "onion" in Latin, but it is also possible that the term derives from the ancient Celtic "head". China, India and the United States are the largest onion producers in the world and a form of divination performed using this bulb was once practiced - especially in rural areas and almost everywhere in Europe.