Extra virgin olive oil is one of the most important ingredients in Italian kitchens, used either straight from the bottle or for making sweet and savoury recipes. Everyone uses it and everyone enjoys it, although there are certain erroneous beliefs surrounding it that influence the behaviour of consumers.
“Extra virgin olive oil improves with age”.
Many food products, such as cheese and wine, will improve over time. Extra virgin olive oil, however, declines in quality as it ages. Because this oil is made from fruit straight from the tree, and processed using mechanical methods, it reaches the peak of its quality as soon as the olives are transformed into oil. After that, the distinctive aromas start to diminish and certain quality indicators such as the acidity and peroxide value begin to slowly decline. It is therefore advisable to keep the oil in a cool place away from direct light and to consume it within 18 months of pressing.
“The greener the extra virgin olive oil, the better it is.”
Many people believe that good quality extra virgin olive should be green in colour. In fact, the colour of extra virgin olive oil can vary from straw yellow to bright green, and is not in itself an indicator of quality. In fact, the colour mainly depends on the amount of chlorophyll in the oil, which is in turn dependent on the olive variety (cultivar) being used, and on the ripeness of the fruit: the earlier the harvest, the higher the concentration of chlorophyll.
The colour of the oil can in fact be very persuasive, and professional tasters generally use a dark glass during tasting sessions to avoid being influenced by it in any way.
We should also point out that the chlorophyll degrades over time, so the colour of the oil becomes increasingly yellow.
“If extra virgin olive oil stings your throat, this means that it’s acidic.”
We cannot actually detect the acidity of olive oil, because the taste buds on our tongues are not “tuned” to recognise the presence of the free acids in the oil. The tingling sensation in the throat that we may experience when tasting extra virgin olive oil is largely down to the number of phenolic compounds (polyphenols) in the oil, which depend on the olive variety and on the ripeness of the fruit.
A high concentration of bio-active phenolic compounds, as found in Coratina oil, has an important antioxidant effect on the oil itself, protecting the Low Density Lipoprotein (LDL) cholesterol from oxidative damage.
“Olive oil is not suitable for frying.”
Olive oil is great for frying because it is very resistant to high temperatures and does not undergo oxidative degradation. The temperature at which substances harmful to health start to form (the so-called “smoke point”) is 210°C for olive oil, while for most seed oils it is about 160°C to 190°C.
The “smoke point” of an oil depends mainly on its content of free fatty acids. Unlike seed oils, olive oil abounds in monounsaturated fatty acids, which are very resistant to high temperatures. It is also rich in antioxidants, which counteract the oxidation process triggered by contact between the burning oil and oxygen.
“If it freezes in winter, it’s extra virgin olive oil.”
Just like any other oil, extra-virgin olive oil may freeze if stored at low temperatures, so it does not follow that if an oil freezes it must be extra-virgin. To be described as “extra virgin” an olive oil must meet certain chemical and sensory criteria set out in the regulations, and must undergo laboratory tests and sensory analysis by certified bodies and professionals.
Oils not made from olives can also freeze. Crystallisation (which is reversible once the oil is brought back to room temperature) is related both to the presence of waxes in the oil and to their different content of saturated, mono- and polyunsaturated fatty acids. Saturated fatty acids (present in coconut oil or palm oil) crystallise at temperatures close to room temperature; monounsaturated fatty acids (found in olive oil) crystallise at about 7 to 8 degrees, while polyunsaturated fatty acids (present in the main seed oils) crystallise at lower temperatures.
Ideally, oil should be stored at a constant temperature of 14 to 18°C.
“Unfiltered oil is synonymous with higher quality.”
The thickness of an extra virgin olive oil should not affect your choice of purchase.
Olive oil takes on a cloudy appearance when it is unfiltered and still contains moisture and small particles of pulp. Must oil certainly has a very winning appearance, conveying the idea of a more genuine product than a filtered oil. However, this cloudy extra virgin oil deteriorates much faster, because the suspended particles form a deposit on the bottom, which then turns rancid and degrades the sensory properties of the oil.
“Extra virgin olive oil is hard to digest.”
Extra virgin olive oil is easily digestible; indeed, paediatricians include it in the recommended diet for newly-weaned babies, and doctors advise its consumption to elderly patients with digestive problems.
The highly digestible nature of extra virgin olive oil is due to its content of oleic acid. This stimulates the functioning of the gallbladder, encouraging the release of bile juices and promoting digestion.
Extra virgin olive oil is easier to digest than seed oils, margarine, butter or lard, and also has the advantage of making dishes more appetising without making them heavier, naturally encouraging good digestion in our systems.