We consume every year 600 thousand tons of olive oil and 700 thousand of that of seeds (data from Unaprol, the olive oil consortium of the country). «Most of the products have interesting nutritional properties, but none can compete with the extra virgin», Says Dr. Giulia Sturabotti, a physician expert in nutrition, hygiene and preventive medicine in Rome.
With its help we explain what they are the characteristics of each type and how to best use it in the kitchen.
Focus on cold-pressed ones
Regardless of the type, the best oil is "cold pressed" (or extracted with mechanical procedures), which maintains its nutritional characteristics unaltered and has no traces of chemical substances used for refining.
How to orient yourself, however, to understand where the raw material comes from? "The label of extra virgin olive oil must indicate the country or area of origin of the olives (EU or non-EU). Those of the country are a guarantee of absolute quality: if you bet on oils a European Dop trademark (Protected Designation of Origin) or Igp (Protected Geographical Indication), you are assured of an excellent level product, obtained by respecting very strict rules ”, explains Dr. Giulia Sturabotti.
«The identity card of seed oils, on the other hand, is much less complete. In fact, it is not yet mandatory to declare the provenance of the raw material. Only for products made in the country and intended for retail sale in our country it is essential to indicate the location of the production or packaging plant ".
At the restaurant he refuses the oil jug
For a few years in the restaurants of the village it is compulsory to bring only to the tables olive oil bottles with anti-topping cap. «The law was made necessary to counteract the bad habit of pouring“ new ”oil into containers, a procedure that can favor rapid rancidity.
With the topping upFurthermore, the consumer cannot know with certainty the origin and characteristics of the product. For example, instead of extra virgin olive oil, the restaurateur could add peanut oil, putting the health of the people at risk. allergic.
Unfortunately, however, not all the places comply with the legislation and there are even those who, instead of bottles, continue to use old cruets or ampoules "of the grandmother", banned since 2006.
The advice is to protect yourself by claiming only bottles in accordance with law. An empirical check can then help to understand if the anti-topping cap has been tampered with: when the bottle shows traces of oil on the outside, it is likely that this has happened ”, warns Dr. Giulia Sturabotti.
Extra virgin olive oil
He is the undisputed protagonist of the Mediterranean diet: «The merit is above all of the quality of its lipids, mainly monounsaturated and, in particular, of the oleic acid.
A research from the Country Society of Diabetology, published in Diabetes Care, clarified that, thanks to the combination of these fats with antioxidants belonging to the class of polyphenols, extra virgin olive oil is able to reduce spikes in blood sugar after meals, helping to prevent type 2 diabetes and the complications of type 1 diabetes », observes Dr. Sturabotti.
Not only that, because this oil also has an optimal ratio between essential polyunsaturated fatty acids Omega 3 and 6: «So it keeps the cardiovascular system in good health and fights inflammations of the whole body.
Numerous studies, then, have shown that it defends us from neurodegenerative diseases: an authoritative American survey published in Chemical Neuroscience has revealed that, due to the content of a substance called oleocanthal, it can reduce the risk of getting Alzheimer's. Finally, it is very rich in antioxidants, including carotenoids and vitamin E, with anticancer properties ».
So that it can boast of the wording extra virgin, as well as being extracted only with mechanical procedures and having a maximum acidity of 0,8%, (i.e. 0,8 g of oleic acid per 100 g), the oil must be free of taste imperfections and possess particular characteristics of aroma and flavor (rich, intense, spicy) evaluated by a committee of experts and not found through the chemical examination. «This is established by the commercial classification of oils envisaged by EEC Reg. 2568/91 and by subsequent additions.
Virgin olive oilon the other hand, also obtained only with mechanical procedures, it has a maximum acidity of 2% and small organoleptic and taste imperfections.
Finally, there is the olive oil, consisting of variable percentages of refined and virgin olive oils, with a content of acidity not exceeding 1% (the law does not establish a minimum quantity of virgin oil for the blend) », explains Giulia Sturabotti.
In the kitchen
Due to its sensory characteristics, extra virgin olive oil is excellent used raw: «In this way the nutritional properties are also kept intact. However it is also ideal in cooking and even for to fry, since its smoke point, that is the temperature above which toxic compounds can form, is very high (about 210 ° C) », explains the expert.
More corn, peanuts, sunflowers
Most people use them for frying (and it is a mistake, because many varieties are altered with heat), but there are many who also use them raw instead of olive oil, thinking that they are lighter.
"In reality they have the same caloric content, in addition to the fact that most of those on the market are refined and, therefore, depleted in essential nutrients. However, in the negozi bio and in some supermarkets, you can also find cold-pressed seed oils: in this case it is worth alternating them with extra virgin olive oil, because they provide excellent doses of polyunsaturated fatty acids, in particular of Omega 6, of which the olive one is lacking.
An American research published in the Journal of Nutrition and Dietetics has shown that, thanks to the presence of these lipids, seed oils are particularly effective for fight cardiovascular diseases. In fact, linoleic acid promotes the metabolism of fats and prevents the formation of cholesterol deposits on the walls of the arteries.
Better, anyway, avoid exceeding the quantities: at high dosages, Omega 6s can in fact have a pro-inflammatory action », warns Dr. Giulia Sturabotti.
In the kitchen
Sunflower oil it is used by the food industry above all for the production of sauces such as mayonnaise: "It is thermolabile (smoke point at 130 ° C), therefore it should preferably be used raw, unless you opt for the "high oleic" type, which has a composition similar to that of olive oil, therefore a much higher content of monounsaturated fats and greater resistance to high temperatures (225 ° C).
Sunflower oil has high amounts of Vitamin E and it is made up of over 50% polyunsaturated acids (in some cases up to 75%) », notes the expert. Not good for frying even corn, which is also present in many industrial products: «It has a composition similar to sunflower oil, in fact it is very rich in linoleic acid and vitamin E, and a smoke point around 160 ° C.
Different is the case ofpeanut oil: monounsaturated fats are prevalent (52%) and their characteristic is precisely that of resist heat well, so it's ok for frying as well (smoke point: 180 ° C if unrefined, 230 ° C if refined). This oil is also very useful for regulating the levels of cholesterol, thanks to the particular lipid composition ».
Hemp, flax, soy...
... and again of sesame and pumpkin: for some time at supermarket you can find new, delicious and tasty oils. But are they also good? “They have several properties. The top is that of flax, very rich in alpha-linolenic acid, precursor of Omega 3 (53,36 g out of 67,85 g total polyunsaturated, compared to just 0,7 g in extra virgin olive oil), therefore ideal for stocking up on these fats, especially in fish allergic.
Soybean oil it has many proteins, vitamins and folic acid and an optimal ratio between Omega 3 and 6: it is very nourishing and has anti-inflammatory properties. That of sesame satisfies and helps to keep pressure and cholesterol under control, due to its content in phytoestrogens.
The oil of hemp seeds it is a source of vitamins, including A and some of the B group, and has a good balance between Omega 3 and 6: stimulates the immune system and defends against cardiovascular diseases. That of pumpkin seeds, which contains many unsaturated fatty acids, it is particularly beneficial for the heart.
In general, unless they are enriched with vitamin E, which protects polyunsaturated acids from oxidation, they are very sensitive to heat and it is good to use them raw or for quick and not overly aggressive cooking », explains the expert.
They are ordered online, on the sites of the stores that sell foreign products, because we can hardly find them, except in some discount stores with foreign brands and wholesale outlets reserved for catering.
The food industry uses them, especially for the preparation of sauces and baked goods, but they are certainly not up to par with other oils because they are very rich in saturated fats.
«Some time ago the fashion of'coconut oil, widely used in Asia: it was believed that its medium-chain triglycerides were able to stimulate metabolism without increasing bad cholesterol.
But this is true only for the virgin product, very difficult to find: almost all of what you find on the market is refined oil in which the quality of the lipids is decidedly low. Not to mention the other tropical oils, like palm and palm kernel, also full of saturated fats », concludes Dr. Sturabotti.
The palm tree is bad for the planet
To plant oil palms, the equivalent of 300 football fields are deforested every hour in Southeast Asia alone. For years, in defense of the environment and the rights of local workers, the non-profit organization operates Roundtable on Sustainable Palm Oil (Rspo), which promotes a type of cultivation that is not harmful to the planet.
“Importers can expect to buy sustainable palm oil. The problem, however, is that at the moment only 18% of world production is RSPO certified ", says Dr. Giorgio Donegani, food technologist