This article was written by Big Les & was originally published in The MuscleTalker May 2011 edition
Olive oil extraction goes back over 5000 years to 2600-2240 BC, which is a long time, as with pretty much every food that has enjoyed centuries of consumption, olives and olive oil is a food packed with nutritional goodness.
Consumption of olive oil has spread massively from the Mediterranean, which still leads the world in consumption per head, to be a worldwide habit, and with increasing interest in health and longevity olive oil consumption has continued to rise.
Olive oil has a reputation as a good health oil, so let's look a little more closely. Chemically speaking olive oil is triacylglycerols, free fatty acids, glycerol, phosphatides, pigments, sterols and bits of olive (and sometimes olive leaf). The main triacyglycerol is oleic acid, a monosaturated omega-9 fatty acid, 55-83% of the total, linoleic acid, a polyunsaturated omega-6 fatty acid, which is 3.5-21%, palmitic acid, a saturated fatty acid, 7.5-20%, stearic acid, a saturated fatty acid, 0.5-5%, alpha-linolenic acid, a polyunsaturated omega-3 fatty acid for 0-1.5% of the olive oil. Olive oil has no trans fatty acids present, and to be classified as olive oil by the International Olive Oil Council, the linolenic acid content has to be lower than 0.9% of the total.
When talking about the health benefits of olive oil a lot of focus has been on the presence of omega-6 and omega-9 fatty acids. However, the benefits of olive oil run deeper than just its favorable fatty acid profile. Olive oil is also a rich source of polyphenols: up to 5mg per 10g grams, where many other nut and seed oils contain no polyphenols. Our understanding of the health benefits of polyphenols is still in its infancy, but we know these compounds when consumed as food bring many health benefits, from lowering the risk of heart disease cancers to healthy skin and eyes. The main phenol compounds in olive oil are hydroxytyrosol and tryrosol.
The colour of olive oil comes from pigments such as chlorophyll, pheophytin and various carotenoids. And we know that carotenoids act as antioxidants, an arsenal that is added to by vitamin E. Olive oil is also a rich source of vitamin K, found in green leafy veggies and essential for healthy blood coagulation.
Convinced that olive oil is more than just health fats in a tasty liquid, here's more about the International Olive Oil Council (IOOC) based in Madrid. The IOOC regulates around 95% of the world's production via its 23 member states, although the USA is not a member, and it is their classification of olive oils that is used in the UK.
Extra-virgin olive oil is produced only from virgin oil production and refers to oil that has both less than 0.8% acidity and is judged to have a superior taste. Virgin olive oil is from virgin oil production where the oil is produced via only physical production methods and has an acidity of less than 2%; it is judged to have good taste. Pure olive oil is usually a blend of refined and virgin oil production.
Refined olive oil is obtained from virgin oils where refining does not alter the chemical structure of the fatty acids and has a free acidity of not more than 0.3%, and has characteristics fixed by the IOOC. Much of the olive oil produced in the Mediterranean is too highly acidic or other wise poor in quality that it needs to be refined to produce an edible product.
Olive oil is great for you but you need to treat it carefully, especially it needs to be kept in a dark and preferably cool place. Strong light, artificial or natural causes photo-oxidation which makes for rancid olive oil. Olive oil will slowly oxidise over time naturally. However, photo-oxidation can occur at up to 30,000 times that which occurs naturally in the oil itself. When oxidized fatty acids such as linoleic and linolenic acid are destroyed, the oil itself will have an unpleasant flavour and odour - often bitter due to the presence of peroxides.
Extra virgin oil and even virgin olive oils are best used cold because heating burns the unrefined particles, while cheaper refined olive oils are better for cooking because they retain their characteristics. Also the strong taste of extra virgin oils can easily overpower a dish while the more subtle taste of refined oil complements it.