Onions come from the alliaceae family and are cultivated all over the world.
They are one of the oldest and most aromatic foods that we can cook with and they
are full of therapeutic properties. The onion plant is a herbaceous plant that
naturally grows every 2 years but it is usually cultivated and thus produces bulbs
annually. The ground these plants grow in is normally fertile but the climate
is not such an important factor, although the optimum climate is fairly cold.
The part of the plant that we eat is the central bulb and it can be eaten raw
or cooked. The way to recognise if an onion is good and fresh is to check the
form, which should be compact, firm and without any marks or mould.
Onions have a very particular taste which provides dishes with an enjoyable flavour and, because of this taste, onions are usually used as the base of minestrones, risottos, meat dishes and sauces. However, this is not all as there are many other dishes that contain onions: French onion soup is a very popular dish, as well as stuffed onions, raw onions in salad and cheese and onion omelettes. The flavour is definitely particular but liked by most people as it gives that extra touch to many meals.
The many varieties and species
The many different varieties can be distinguished by shape, colour and flavour. Another distinction is by usage, that is if the onion is consumed raw or cooked. If you want to consume fresh onions, the best time buy them is in the Spring, but if you want to preserve them, to use in oils or vinegars, the best time to purchase them is in the Summer. There are many different types of onions but it must be said that the most well-known type is the red onion from Tropea, followed by the white onion and then shallots. Red onions usually contain the most aromatic substances but, from a nutritional point of view, there is not much difference between the different types.
Nutritious values and therapeutic properties
100g of fresh onion contains 26Kcal, whereas 100g of dried onion contains 24Kcal. Onions also contain a lot of vitamins (vitamins A, B, E and especially vitamin C), as well as enzymes that help digestion and stimulate the metabolism. Furthermore, they also contain essential minerals such as sulphur, iron, potassium, magnesium, fluoride, calcium, manganese and phosphorus. There are also flavonoids present in onions, that have a diuretic effect, and glucokinin, which is an anti-diabetic plant hormone. However, this plant also has numerous therapeutic uses: in dermatology it can be used as an antibiotic and antibacterial simply by applying the juice to the infected area. It is also an effective expectorant when added to honey and it can even unblock the nostrils. Gargling onion juice is recommended for those with tonsillitis and onions are also advised for those who suffer from thrombosis as the fludifying property they have helps blood circulation. In addition, onions are beneficial for those with bad digestion but it is best to eat cooked onions in this case because, even though they contain less nutrients when cooked, they are more tolerable. Finally, these ‘beneficial bulbs’ act as hypoglycemics, lowering the blood sugar level and allowing diabetics to reduce their insulin doses.
Onions also have homeopathic benefits and, in fact, onions are recommended when we have a cold as they work against the nasal secretion and tearing that comes with a cold.
Consumption and preservation
Onions should be stored at room temperature (and not in the fridge) in a cool, dry place, where they can stay for up to 3 weeks without changing their firmness or colour and where they will not grow shoots. There are no ‘wrong’ ways to consume onion but the only way that could provoke some unpleasant effects is if it is eaten raw as it can cause bad breath. This can be set right, however, by chewing on some cloves.
Onion in phytotherapy and cosmetics
Onion, which, as mentioned, is rich in essential oils and minerals, is used a lot as a remedy in phytotherapy, especially in cases of abscesses or perniosis. Thanks to the presence of essential oils, substances that contain sulphur (which create the typical flavour), vitamin C and minerals, these vegetables are often used in the form of easy to make decoctions: remove the outer skin of the onion, wash the bulb and then slice it with the inner peel still attached. Boil these slices in a pan of water for about 15 minutes and then filter the liquid. After filtration, it is ready to be applied to the necessary area by dabbing it on with some cotton wool.
This onion decoction is also good for beauty, especially for dry or damaged skin, and it can even revitalise hair follicles, thus delaying hair loss.
Onion infusions for various uses
Onion is the principle ingredient in some teas, which are mainly used medicinally. How to make a good infusion? All you need to do is slice up 500g of onion and leave it to soak for 3 days in 1L of dry white wine. The recommended dose is 1 tea, between meals, 3 times a day. This particular drink, which is rich in vitamin C and diuretic salts, is very good for those who suffer from bladder infections, but it is also good for diabetics since, as mentioned, it is a hypoglycaemic.