Edible vegetable oils
Every day we use them in the kitchen, or we eat food preparations that contain them, but do we really know where they come from? Apart from olive oil, which in Italy is one of the most used oils, the result of millennia of agricultural and industrial tradition, there are many other vegetable oils used as food; and their use steadily increases, thanks to their healthiness, compared above all to animal fats.
Fats are made up of lipids, usually oil, butter, lard, margarine, contain more than 90% of lipids; lipids are made up of fatty acids, and are called saturated or unsaturated (polyunsaturated or monounsaturated). Saturated fats, usually solid at room temperature, are usually those of animal origin, and are not very healthy for the body; for this reason it is good to consume them sparingly. The fats that make up vegetable oils are instead mainly composed of polyunsaturated or monounsaturated fatty acids, and are among the healthiest fats for our body.
But since they are very caloric, and some of them are not entirely healthy, why do we continue to eat them?
Yes, fats are very caloric, with about nine calories per gram of product; but they are a fundamental part of the cells of our body; in addition to this some mineral salts and vitamins dissolve only in fats, and therefore if one day we decide to stop eating any type of fat we would face serious nutritional deficiencies.
In addition to this, a part of the cholesterol (which is made up of fats), the one called good, helps us keep the arteries clean, and is therefore necessary for our health. Fatty acids, such as the famous Omega-3 also serve for the correct functioning of the nervous system and the immune system, as well as for the cardiovascular system.
Some further information
Among the best vegetable edible oils olive oil certainly stands out, which contains a large amount of monounsaturated fatty acids, the best from the nutritional point of view and also the most stable, which make it an excellent oil for frying; it also contains numerous polyphenols and other beneficial substances, which make extra virgin olive oil a sort of panacea, to be used in the kitchen for any dish, sweet or savory, but also in herbal medicine and cosmetics.
In the Mediterranean area traditionally olive oil is the most widespread edible oil; apart in Morocco, where the most used oil is the excellent Argan oil. In other populations of the earth, food oils are used that are very different from those we are used to finding at the supermarket; for example, in some areas of Japan and China the oil of the camellia seeds is used a lot, also very rich in monounsaturated fatty acids; also the grapeseed oil is used as edible oil, in some areas where the grape is very cultivated. On a nutritional level, grapeseed oil is very similar to olive oil and camellia oil.
Other oils, more or less used, are almonds or walnuts, and sesame oil, which are decidedly very aromatic oils, whose taste is very particular when used in the kitchen.
Rapeseed oil, which is toxic and unpleasant if not refined, is also widespread in Asia and North America; Italian legislation prohibited its use for food purposes. In Europe, rapeseed is not used to extract oil, but only as forage, or to produce biodiesel.
Main food vegetable fatsCorn oil
Maize is a large herbaceous grass, native to Central and North America, now grown all over the globe; maize plants produce large panicles of hard seeds, of various colors, from pure white to golden yellow, from orange to blue. In fact, the most commonly cultivated varieties in Italy have golden yellow grains, apart from some micro-cultivations, such as the famous Storo red wheat, cultivated in Trentino.
The cultivation is annual, it begins in spring and ends in full summer. From the corn grains you get a flour, used to make polenta, animal feed, sugar syrup and oil. Among the seed oils, it is among the richest in polyunsaturated fats, which make it excellent to use raw, but not very interesting as a frying oil.
Soy, a botanical name glycine max, is a herbaceous plant native to Asia, a legume, cultivated to use its seeds, which are produced in late summer or early autumn, in long pods. Soybean plants are small roundish shrubs, about 45-50 cm high, which dry up as the fruit ripens. Soybeans are used to produce flours, but also to be eaten cooked, such as beans or peas, both fresh and dry. Soybean oil is obtained by chemical means, and the oil obtained contains about 50% of polyunsaturated oils; it is not very suitable for frying, and should preferably be used raw, and kept away from sunlight, because it tends to oxidize easily. It is an oil almost completely devoid of flavor.
Sunflower is an annual plant, belonging to the asteraceae family; millennia of cultivation, and therefore of hybridizations and conservation of particular cultivars, have made the head of the huge sunflower, with a stem up to two meters high and a floral disk up to 45-50 cm wide (let's try to imagine a daisy of such dimensions), to ensure that every single plant produces the greatest possible quantity of seeds. Each flower head is made up of thousands of small dark tubular flowers, with flowers on the edge of the flower heads that carry one or more long and large golden yellow petals; only one large seed is produced from each flower. Sunflower oil is similar to corn oil, from an organoleptic point of view; it is a vegetable oil to be used raw, because if heated it tends to produce unhealthy compounds, as happens with many of the most common seed oils.
The peanut, Arachis hypogea, is a small annual herbaceous plant, native to South America; it produces small plants, little more than fifty centimeters high, with thin stems that bear pinnate leaflets, and yellow flowers. After pollination, the flowers turn downwards, and the ovary makes its way into the ground, where the fruit thickens. Peanuts therefore grow underground, despite being fruits and not tubers; inside each small pod there are some oily seeds. It is a good vegetable oil that contains about 50% of monounsaturated fatty acids; It is a stable oil, suitable for hot use, even for frying.
Vegetable food oils: Margarine
Margarine is a buttery substance, based on saturated vegetable fats, therefore it has all the disadvantages of butter or lard, despite being of vegetable origin; in addition to this, many margarines are chemically refined, or hardened through the hydrogenation of fats. Hydrogenated fats are among the most harmful to our health, as they are difficult to metabolize, and help to form plaques on the arteries. In Italy margarine is little used, as butter or extra virgin olive oil is preferred. On the market there are also margarines of excellent quality, which do not have hydrogenated vegetable oils; however, it remains a poor quality fat, which it would not be recommended to use for food.