Fats and Oils - Olive Oil
Olive oil is approximately 77 per cent monounsaturated fat, and is an excellent source of Vitamin E. Studies have shown that the use of olive oil increases the absorption of the fat soluble vitamins, A, D, E and K, and has the added benefit of contributing dozens of valuable antioxidants.
The oil pressed from the pulp of the ripe fruit of the olive tree, Olea Europaea.
Origin and History
Cultivation of the olive tree appears to have originated about 6000 years ago in the eastern Mediterranean region, although it grew wild before that time. Olive oil was a major export product of Greece as far back as 2500 B.C. The olive tree was developed by the Syrians and Palestinians into a compact, oil-rich variety which is now grown along the entire shores of the Mediterranean and wherever a Mediterranean-type climate prevails. The largest producers of olive oil today are Spain and Italy. Unlike most other vegetable oils, good virgin grades of olive oil are consumed as a food without refining or other processing.
Buying and Storage
Olive oils have a wide variety of flavors ranging from light and buttery to very fruity. The color also varies from yellow to green, depending on the region in which the fruit is grown and from pale to dark, depending on the type of oil. Virgin oil has a stronger flavor and color than refined or pure oil. The flavor and color of the pure oils also vary, depending on the relative amounts of virgin and refined oils blended together.
Olive oil is more stable to oxidation than most liquid oils owing to its low content of polyunsaturated fats. Store in a sealed container at room temperature, out of direct light.
Preparation and Use
The virgin and pure oils are used chiefly as salad and cooking oils. For those interested in reducing their cholesterol, olive oil or extra-virgin olive oil may be used as a substitute for butter in baking. The International Olive Oil Council advises that 20 g butter can be replaced by 2 ¼ teaspoons extra-virgin olive oil, 55 g butter by ¼ cup oil, and 220 g butter by ¾ cup oil. The Council also says that 'olive oil has a small fat crystal which yields even, fine-textured baked goods, and cakes have a moist and tender crumb'. Olive oil is unsuitable for deep frying as it cannot tolerate high frying temperatures.
Residue oil, if refined, may be included in edible products such as blended vegetable oils, but may not legally be sold as 'olive' oil. The inedible residue oil (also known as sulphur oil or olive kernel oil) is widely used in soap-making.
Once it was common to refer to 'cold-pressed' and 'first-pressed' olive oils. Technology has advanced and these terms are largely meaningless today. Most olive oil is now produced with only one pressing, but more powerful presses are used. The final acidity of the oil varies from year to year and crop to crop. It is this measurement that distinguishes an oil that may be sold as extra-virgin and one that may be sold as virgin olive oil.
Extra-virgin olive oil is a virgin olive oil of outstanding flavor, color and aroma that has a maximum acidity of no more than 1 per cent. Virgin olive oil indicates a good but slightly subdued 'fruity' flavor; the acidity may not exceed 1.5 per cent. Olive oil is blended from refined, lesser-quality virgin olive oil and unrefined virgin olive oil for extra flavor.