Olive oil is a fat obtained from the olive, a traditional tree crop of the Mediterranean Basin. The oil is produced by grinding whole olives and extracting the oil by mechanical or chemical means. Olive oils are commonly used in cooking, cosmetics, pharmaceuticals and soaps and as fuel for traditional oil lamps. Most heavily used in the Mediterranean, near its origin, the largest consumption of olive oil per person can still be found in Greece. Although currently, Spain produces 43.8% of the world production of olive oil, with Italy coming in second at 21.5% of the world’s olive oil production; Greece now accounts for only 12.1% of world production.
We’ve all heard olive oil referred to as ‘Virgin’ or ‘Extra Virgin’, but what exactly do these terms mean? They refer to the different commercial grades of the Oil extracted from the olive fruit which is classified as: Virgin, which means the oil was produced by the use of physical means and no chemical treatment. The term virgin oil referring to production is different from Virgin Oil on a retail label (see next section.) Refined, which means that the oil has been chemically treated to neutralize strong tastes (characterized as defects) and neutralize the acid content (free fatty acids.) Refined oil is commonly regarded as lower quality than virgin oil; oils with the retail labels extra-virgin olive oil and virgin olive oil cannot contain any refined oil. Olive pomace oil, which means oil extracted from the pomace using solvents, mostly hexane, and by heat.
These commercial grades do differ slightly to the retail grades which members of the International Olive Council adhere to. Then there is the U.S.’s own set of standards, set by the U.S.D.A. The U.S. Department of Agriculture has a four-part grading of olive oil based on acidity, absence of defects, odor and flavor. They are: U.S. Extra Virgin Olive Oil for oil with excellent flavor and odor and free fatty acid content of not more than 0.8g per 100g (0.8%); U.S. Virgin Olive Oil for oil with reasonably good flavor and odor and free fatty acid content of not more than 2g per 100g (2%); U.S. Virgin Olive Oil Not Fit For Human Consumption Without Further Processing is a virgin oil of poor flavor and odor; U.S. Olive Oil is an oil mix of both virgin and refined oils; U.S. Refined Olive Oil is an oil made from refined oils with some restrictions on the processing. Note these grades are voluntary for U.S. retail labels. Certification is available from the USDA on a fee-for-service basis.
There are many health benefits of olive oil. Evidence suggests that a higher proportion of monounsaturated fats in the diet is linked with a reduction in the risk of coronary heart disease. This is significant because olive oil is considerably rich in monounsaturated fats. In fact, in the United States, producers of olive oil may place the following health claim on product labels:
Limited and not conclusive scientific evidence suggests that eating about 2 tbsp. (23 g) of olive oil daily may reduce the risk of coronary heart disease due to the monounsaturated fat in olive oil. To achieve this possible benefit, olive oil is to replace a similar amount of saturated fat and not increase the total number of calories you eat in a day.
Further, Olive oil contains a wide variety of valuable antioxidants that are not found in other oils. Studies suggest that olive oil has a protective effect against certain malignant tumors in the breast, prostate, endometrium and digestive tract. Research has revealed that the type rather than the quantity of fat seems to have more implications for cancer incidence Even newer research suggested that a substance in Olive Oil called oleocanthal, has effects that protect nerve cells from the kind of damage that occurs in Alzheimer's Disease.
Cooking with Olive Oil
Choosing a cold-pressed olive oil can be similar to selecting a wine; the flavors of olive oils vary considerably and particular oil may be more suited for a particular dish.
An important issue often not realized in countries that do not produce olive oil is that the freshness makes a big difference. A very fresh oil, as available in an oil producing region, tastes noticeably different from the older oils available elsewhere. In time, oils deteriorate and become stale. One-year old oil may be still pleasant to the taste, but it is surely less fragrant than fresh oil. After the first year, olive oil should be used for cooking, not for foods to be eaten cold, like salads.
The taste of the olive oil is further influenced by the varietals used to produce the oil from and by the moment when the olives are harvested and ground (less ripe olives give more bitter and spicy flavors, which is a positive attribute – riper olives give a sweeter sensation in the oil.)
Not only can you cook just about anything with olive oil, due to all the health benefits of olive oil you should cook just about everything with it instead of using less healthy fats or butter. Due to the range of flavors amongst grades of olive oils, there is an oil for every food you are preparing. Use very high quality extra virgin oil as a finish and/or condiment poured over salad, rices, potatoes, vegetables, poultry and more. Robust extra virgin oils are perfect for cooking seafood, to make marinades, or on strongly flavored ingredients such as peppers or garlic. A medium intensity oil is delicious with mozzarella and for dipping bread, for frying and sautéing. More mild olive oils work well when used in baking. As it’s all about what you think tastes good, you should have several different kinds on hand and experiment pairing oils with your dishes. Since high quality Olive Oils have a higher smoke point than other oils (the temperature at which the oil begins to break down and smoke) olive oil is perfect for frying foods as well.
In order to maintain optimal flavor and freshness, be sure to store it in a cool, dry place away from heat, light and air. When the oils are exposed to heat, light and air the valuable nutrients begin to oxidize and lose flavor. Take care not to store olive oil in plastic containers since the oils can leach harmful substances out of the plastic…glass is best. Lastly, olive oil should be consumed within two years of pressing, before flavors begin to deteriorate.