What is Olive Oil?
“Olive oil” is how we refer to the oil obtained from the fruit of olive trees. People have been eating olive oil for thousands of years and it is now more popular than ever, thanks to its many proven health benefits and its culinary usefulness.
Virgin Olive Oil is obtained from the fruit of the olive tree, solely by mechanical or other physical means under condition, particularly thermal conditions, that do not lead to alterations in the oil, and which has not undergone any treatment other than washing, decantation, centrifugation and filtration, to the exclusion of oils obtained by solvent or re-esterification processes and any mixture with oils of other kinds.
How Olive Oil is made?
After olives are picked and washed, they’re crushed – sometimes between two big stones, but now more commonly by steel blades.
The resulting paste is stirred to release the oil droplets in a process called maceration, before being spun in a centrifuge to pull out the oil and water. After the water is removed, what is left is olive oil.
Why Cold Pressed?
Cold Extracted or Cold Pressed indicates that milling temperatures were kept below 30oC, preventing the destruction of the temperature sensitive vitamins, antioxidants and flavor compounds.
The Antioxidant Properties of Olive oil
What are Antioxidants and Oxidative Stress?
Oxidation is a process that occurs not only when oil is being produced, but also inside our own bodies. Reactions occur continually inside the body, giving rise to the formation of free radicals (peroxidants). As a rule, free radicals do not cause severe damage thanks to the protection provided by antioxidants, which help to keep a balance up to a point. If the balance is spoiled, however, "oxidative stress" occurs, leading to the deterioration of normal cell functions and even cell death.
Oxidation is a complex, fundamental phenomenon in the process of cell aging. Lipid or fat peroxidation tends to be proportional to the number of double bonds in a compound, explaining why oleic acid shows little susceptibility to oxidation.
Cell membranes contain a large amount of fat and cholesterol and their composition depends on diet. When the diet contains a lot of olive oil, the cells are more resistant to oxidation, they do not deteriorate as much and aging is slower.
Approximately 1.5% of olive oil is made up of the unsaponifiable fraction, which contains antioxidants. Virgin olive oil contains the largest quantities of these substances and other minor components.
Antioxidants in Olive Oil
Vitamin E (alpha-tocopherol), carotenoids and phenolic compounds (simple phenols such as hydroxytyrosol and complex phenols such as oleuropein) are all antioxidants whose activity has been demonstrated in vitro and recently in vivo, revealing further advantages in the prevention of certain diseases and also of aging.
The phenolic content of olive oils varies according to the climatic conditions in the producing area, when the olives are harvested and how ripe they are when picked. Oil production and storage methods also have an influence. Phenols have countless biological properties, for instance, hydroxytyrosol inhibits platelet aggregation and it is anti-inflammatory and oleuropein encourages the formation of nitric acid, which is a powerful vasodilator and exerts a strong anti-bacterial effect.
Oxidized LDLs are known to be atherogenic, which is where olive oil steps in because it has a beneficial, protective effect against LDL oxidation. Moreover, it also strengthens other cells in the body against the toxic effects of oxidants.
The high antioxidant content of the Mediterranean Diet appears to contribute significantly to its effect on longevity.
These antioxidants are found in fresh fruit and vegetables. Because it is the only oil to be obtained from a fruit, olive oil retains a host of substances, antioxidants and vitamins that give it added nutritional value.
The explanation behind this high content of antioxidants is probably that because the olive is a fruit that is exposed to the air, it has to defend itself from oxygen. It, therefore, synthesizes a larger amount of antioxidants, which pass through to the oil.
Virgin olive oil, i.e. olive oil that has not been refined or industrially treated, is particularly rich in these substances and it has a strong antioxidant effect, protecting against damage from free radicals (scavenger activity) and against the formation of cancer.
The Categories of Olive Oil
Not all Olive Oils are the same and you have to check always the product label before buying one.
There are many misconceptions and misunderstandings regarding Olive Oil. The different grades of Olive Oil and associated standards are defined by the International Olive Council.
In summary, there are five different types of Olive Oil:
1. Extra Virgin Olive Oil
2. Virgin Olive Oil
3. Refined Olive Oil
4. Olive Pomace Oil
5. Lampante Oil
1. Extra Virgin Olive Oil - This is the best Olive Oil you can offer yourself.
The definition of Extra Virgin Olive Oil is very precise in regard to production methods, taste, and chemical composition. To be certified for the “Extra Virgin” label, an olive oil:
Must come from the first pressing of fresh olives, normally within 24 hours of harvesting.
Must be extracted by non-chemical, mechanical means, and without the use of excessive heat, specifically below 28C (cold-pressed).
The free fatty acid or acidity level must be less than 0.8%.
Must be defect-free – having a perfect taste and aroma (organoleptic evaluation is necessary).
Extra Virgin is the highest grade and best tasting Olive Oil.
2. Virgin Olive Oil
Virgin Olive Oil also comes from the first pressing and must have an acidity level of less than 2%, therefore, it is of inferior quality to Extra Virgin Olive Oil. Its flavor intensity can vary and its taste is milder than Extra Virgin Olive Oil.
3. Refined Olive Oil
These are Olive Oils that have been refined by using agents such as acids, alkalis, and heat to extract as much oil as possible from the olive pulp that remains after the first pressing. The result is a fattier and more acidic oil that lacks taste, aroma and natural antioxidants. This is why producers need to add unrefined Extra Virgin or Virgin Olive Oil to impart some flavor, color and aroma into the blend.
Terms such as “pure” or “100% pure” or “Light” or “Premium” are made up terms used by large producers and supermarkets. If the label states “pure” or “100% pure” or “Light” then the Olive Oil is a refined oil lacking the taste, aroma and quality of Extra Virgin Olive Oil.
4. Olive – Pomace Oil
The lowest grade of olive oil made from the by-products of extra virgin olive oil production. Olive skins, seeds and pulp are heated and the remaining oil is extracted using hexane, a solvent. The result, pomace oil, is then put through the refining process, similar to pure or light olive oil. Pomace olive oil is bland and extremely low in antioxidants.
5. Lampante Oil
Oil with severe defects, usually from bad fruit or poor processing practices. It is not fit for human consumption until it has been refined. Oil with severe defects, usually from bad fruit or poor processing practices. It is not fit for human consumption until it has been refined.
How to Store Olive Oil
Due to olive oil's high monounsaturated fat content, it can be stored longer than most other oils as long as it's stored properly. Oils are fragile and need to be treated gently to preserve their healthful properties and to keep them from becoming a health hazard full of free radicals.
When choosing your storage location, remember that heat, air, and light are the enemies of oil. These elements help create free radicals, which eventually lead to excessive oxidation and rancidity in the oil that will leave a bad taste in your mouth. Even worse, oxidation and free radicals contribute to heart disease and cancer.
Rancidity can set in long before you can taste it or smell it. Even though rancid oil doesn't pose a food-safety type of health risk, the less you consume, the better.
The best storage containers for olive oil are made of either tinted glass (to keep out light) or a non-reactive metal, such as stainless steel. Avoid metal containers made of iron or copper because the chemical reactions between the olive oil and those metals create toxic compounds. Avoid most plastic, too; oil can absorb noxious substances such as polyvinyl chlorides (PVCs) out of the plastic. Containers also need a tight cap or lid to keep out the unwanted air.
Unlike wine, oil does not improve with age. As olive oil gets older, it gradually breaks down, more free oleic acid is formed, the acidity level rises, and flavor weakens. Extra-virgin oils keep better because they have a low acidity level to start with, but you should use lower-quality oils within months because they start out with higher acidity levels. As oil sits on your shelf, its acidity level rises daily, and soon it is not palatable.
You'll get the best quality and flavor from your olive oil if you use it within a year of pressing. Olive oil remains at its peak for about two or three months after pressing, but unfortunately, few labels carry bottling dates or "use by" dates, let alone pressing dates.
More is at issue than flavor, however. Research shows the nutrients in olive oil degrade over time.
In a study that appeared in the May 2004 issue of the Journal of Agriculture and Food Chemistry, Spanish researchers tested virgin olive oil that had been stored for 12 months under perfect conditions.
What they found was quite surprising: After 12 months, many of the oil's prime healing substances had practically vanished. All the vitamin E was gone, as much as 30 percent of the chlorophyll had deteriorated, and 40 percent of the beta-carotene had disintegrated. Phenol levels had dropped dramatically, too.