Did you know that in Italy, large producers organize olive oil tastings similar to wine tastings?
Or that, in Egypt, sometimes people eat only flatbread accompanied by the same olive oil, which is also a vibrant green, very aromatic, with the same slightly bitter and slightly peppery taste?
Indeed, even oils can be categorized as either basic or top-class, some having an extremely delicate, fruity-floral taste, with aromas of freshly mown grass, and an almost fluorescent green color.
Here, cold-pressed oils (especially sunflower oil) started appearing timidly on shelves after the ’90s, and gradually, people began to develop a taste for them.
In the meantime, the market opened up, and the famous olive oil began to come in, followed by all sorts of rarities, such as sesame oil, for example.
It’s true that, in our country, oils used for tastings haven’t really made their way in yet, except perhaps in high-end restaurants, but we still have a wide variety of oils.
What are cold-pressed oils?
Cold-pressed oil is oil that has been obtained through a production technology that involves using a low thermal regime.
This is because, when higher temperatures are used during the pressing process, it helps to fluidize the oil and get a higher yield from the same amount of raw material, thus a better efficiency. True. However, under the action of heat, the oil’s aroma and color will degrade, along with a decrease in its nutritional value.
For this reason, cold-pressed oil tends to be more expensive than regular commercial oil (which, in addition to pressing, can also be extracted using hydrocarbons, followed by various refining processes like decolorization, deodorization, etc., to make it suitable for consumption). Although cold-pressed oil is more expensive, it is also of much higher quality.
The term “cold-pressed oil” is subject to different regulations depending on its origin, meaning in which part of the world it was made.
In the European Union, for example, oil labeled as cold-pressed must be produced in an environment that never exceeds a certain temperature. The temperature varies depending on the oil, but it is generally around 27°C.
On the other hand, in the United States, the labeling of oil is not regulated, so “cold-pressed oil” may actually be oil obtained under conditions other than cold pressing. Consumers are required to rely on sight, smell, or taste to determine whether the oil is truly cold-pressed.
Obtaining cold-pressed oil.
To obtain the oil, the raw material (nuts, seeds, fruits, etc.) is transformed into a paste.
The paste undergoes a malaxation process, which involves slow agitation that encourages the oil to gather.
To extract the oil, pressure is applied to the paste, forcing the oil out of it.
In the case of hot pressing, heating the paste will change the viscosity of the oil, allowing it to flow more easily, thus increasing oil production. Some producers mix the paste with warm water or heat the paste before pressing.
True cold-pressed oil (the so-called extra virgin) is obtained only from the first pressing of the paste.
Once the oil is produced, it is filtered to remove any impurities and then bottled.
Some companies produce a cheaper oil, which is actually obtained from the oil cake (the so-called “olio di sansa di oliva” – in the case of olives) produced in a high-pressure environment. It is also sometimes called oil obtained from the second pressing.
High pressure is necessary for certain raw materials, such as nuts or some seeds, which create a thick cake, and this has the drawback of raising the temperature due to the friction of the seeds.
Some oils obtained in this way can still be labeled as cold-pressed, as the increase in temperature is not significant.
Therefore, companies must label these oils correctly, using formulations like “oil from cold-pressed oil cake.”
Due to the small amount of oil left in this “cake” that is extracted and for economic reasons, it is often mixed with virgin oil for better flavor, resulting in various “varieties” on the market (for example, 20% virgin and the rest from the cake, etc.).
Traditionally, oils have been extracted worldwide from oilseeds such as soy, sunflower, and other sources like olives and corn. Other plants were used mainly for technical purposes, such as rapeseed or flax.
Recently, due to research, it has been found that oil can be extracted from almost any plant, especially from its seeds, which naturally concentrate the highest amount of fats.
Thus, flax, which was once used in the paint industry, has now found therapeutic uses, while grape seeds, which were previously considered waste, have become highly sought after, as have cereals, which are not used for the grains themselves but for their germ, which has a high lipid content. And the list can continue.
Additionally, because these new sources of oils are not produced in industrial quantities like traditional sources, and the extraction process is more difficult due to a lower fat content than in traditional sources, these oils are usually packaged in smaller quantities and their price is much higher than that of any regular cooking oil.
The use of cold-pressed oils.
Many top chefs consider cold-pressed oil to have a superior flavor and use it predominantly in their specialties. For dressings and dishes where the oil’s flavor will play an important role, cold-pressed oil is generally superior to other types of oil, and that’s why it’s preferred.
However, when the oil is used for heating while cooking, consumers should be more concerned with the smoke point or burning point of the oil they are using. Generally, the smoke point is higher the more refined the oil is (it has fewer substances that can burn).
To begin, let’s define a few terms related to this topic:
Smoke Point (Burning Point)
The burning point of an oil is the temperature at which it begins to smoke, irreversibly altering its qualities, decomposing into glycerol and free fatty acids. The glycerol, due to the burning process, transforms into acrolein, a toxic substance that can cause serious damage to the human body over time.
Although refined oils have higher burning points than cold-pressed oils, through refinement, they can reach temperatures that exceed their smoke points, and they are processed both chemically and physically, making them much more toxic than a cold-pressed oil that has simply reached its smoke point.
Saturated Fats
Saturated fats, with hydrogen atoms, are considered “bad,” responsible for increasing total cholesterol levels in the blood, especially the “bad” LDL cholesterol, raising the risk of cardiovascular diseases. However, some studies have proven that certain types of saturated fats are metabolized very quickly and are immediately transformed into energy, never being stored.
Foods rich in saturated fats remain solid at room temperature.
Unsaturated Fats
These are the so-called “good” fats, healthy fats that the body needs for vital functions and for the absorption of fat-soluble vitamins A, D, and E.
They have a soft or even liquid consistency at low temperatures, such as those in the fridge.
Depending on the number of double bonds they contain, they can be monounsaturated (with one double bond) or polyunsaturated (with multiple double bonds).
Monounsaturated Fats
These are rich in monounsaturated fatty acids. They increase the “good” cholesterol levels and decrease the “bad” cholesterol levels.
This group includes oleic acid, the most commonly found in nature, which is the basis for the formation of omega-9 fatty acids, naturally produced by the body and used in place of omega-3 and omega-6 when these are insufficient in the diet.
Polyunsaturated Fats
These are rich in polyunsaturated fatty acids, which are essential for the body but cannot be produced by it, being synthesized only by plants.
Polyunsaturated fatty acids, also known as essential fatty acids (EFA), omega-3 (alpha-linolenic acid), and omega-6 (linoleic acid), play a crucial role in brain function and normal growth and development. They help reduce skin and joint inflammation, support arterial flexibility, and help thin the blood. Omega-3 EFAs also affect blood pressure.
Optimal Fatty Acid Ratio
For EFAs, the general recommendation is a daily intake ratio of 1:1:1 (saturated:monounsaturated:polyunsaturated), and a ratio of 5:1 for omega-6:omega-3 (about 2 grams of omega-3 per day for men and slightly less for women).
Trans Fatty Acids
Trans fats (TFA) are isomers of unsaturated fatty acids and occur under chemical or physical factors, less frequently enzymatic ones, especially during hydrogenation.
Although most TFAs are harmful to health, there are also some particularly beneficial forms, such as conjugated linoleic acid.