Olive oil is a fat obtained from the olive (the fruit of Olea europaea; family Oleaceae), 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. It is commonly used in cooking, cosmetics,pharmaceuticals, and soaps and as a fuel for traditional oil lamps. Olive oil is used throughout the world, but especially in the Mediterranean countries and, in particular, in Greece where the largest consumption per person can be found.
Health benefits attributed to fat composition
Evidence from epidemiological studies also suggests that a higher proportion of monounsaturated fats in the diet is linked with a reduction in the risk of coronary heart disease.[56] This is significant because olive oil is considerably rich in monounsaturated fats, most notably oleic acid.
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.
This decision was announced November 1, 2004, by the Food and Drug Administration after application was made to the FDA by producers. Similar labels are permitted for foods rich in omega-3 fatty acids such as walnuts and hemp seed.
There is a large body of clinical data to show that consumption of olive oil can provide heart health benefits such as favourable effects on cholesterol regulation and LDL cholesterol oxidation, and that it exerts antiinflamatory, antithrombotic, antihypertensive as well as vasodilatory effects both in animals and in humans. Additionally, olive oil protects against heart disease as it controls the "bad" levels of LDL cholesterol and raises levels of the "good" cholesterol, HDL
Another health benefit of olive oil seems to be its property to displace omega-6 fatty acids, while not having any impact on omega-3 fatty acids. This is conditional on olive oil displacing foods that are richer in omega-6, which includes most vegetable oils, rather than foods which contain less omega-6, such as butter. This way, olive oil helps to build a more healthy balance between omega-6 fats and omega-3 fats.
Unlike saturated fats, olive oil lowers total cholesterol and LDL levels in the blood. It is also known to lower blood sugar levels and blood pressure.
Olive oil contains the monounsaturated fatty acid oleic acid, antioxidants such as vitamin E and carotenoids, and oleuropein, a chemical that may help prevent the oxidation of LDL particles.
[edit]Health benefits attributed to phenolic composition
Olive oil contains a wide variety of valuable antioxidants that are not found in other oils. Hydroxytyrosol is thought to be the main antioxidant compound in olives, and believed to play a significant role in the many health benefits attributed to olive oil. Epidemiological studies suggest that olive oil has a protective effect against certain malignant tumours 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.
Hydroxytyrosol (2-(3,4-Di-hydroxyphenyl)-ethanol or DHPE) is a phenolic component of extra-virgin olive oil. An olive oil fraction containing DHPE can inhibit platelet aggregation and eicosanoid(thromboxane B2) formation in vitro.
Oleocanthal from olive oil is a non-selective inhibitor of cyclooxygenase (COX) similar to classical NSAIDs like ibuprofen. It has been suggested that long-term consumption of small quantities of this compound from olive oil may be responsible in part for the low incidence of heart disease associated with a Mediterranean diet.
Culinary use
Olive oil is the main cooking oil in countries surrounding the Mediterranean Sea.
Extra virgin olive oil is mostly used as a salad dressing and as an ingredient in salad dressings. It is also used with foods to be eaten cold. If uncompromised by heat, the flavor is stronger. It also can be used for sautéing.
The higher the temperature to which the olive oil is heated, the higher the risk of compromising its taste. When extra virgin olive oil is heated above 210–216 °C (410–421 °F), depending on its free fatty acid content, the unrefined particles within the oil are burned. This leads to deteriorated taste. Also, the pronounced taste of extra virgin olive oil is not a taste most people like to associate with their deep fried foods. Refined olive oils are perfectly suited for deep frying foods and should be replaced after several uses.
Choosing a cold-pressed olive oil can be similar to selecting a wine. The flavour of these oils varies considerably and a particular oil may be more suited for a particular dish. Also, people who like lots of tannins in their red wines might prefer more bitter olive oils.
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 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).
Olive oil has more uses than as food; it also works as a natural and safe lubricant, such as lubricating the machinery that is used within the kitchen (grinders, blenders, cookware, etc.)
| Vegetable oils | |||||||
|---|---|---|---|---|---|---|---|
| Type | Saturated fatty acids[76] | Mono- unsaturated fatty acids[76] | Polyunsaturated fatty acids | Oleic acid (ω-9) | Smoke point | ||
| Total poly[76] | linolenic acid (ω-3) | Linoleic acid (ω-6) | |||||
| Not hydrogenated[77] | |||||||
| Canola (rapeseed) | 7.365 | 63.276 | 28.142 | - | - | - | 400 °F (204 °C)[78] |
| Coconut | 91.00 | 6.000 | 3.000 | - | 2 | 6 | 350 °F (177 °C)[78] |
| Corn | 12.948 | 27.576 | 54.677 | 1 | 58 | 28 | 450 °F (232 °C)[79] |
| Cottonseed | 25.900 | 17.800 | 51.900 | 1 | 54 | 19 | 420 °F (216 °C)[79] |
| Flaxseed/Linseed (European)[80] | 6 - 9 | 10 - 22 | 68 - 89 | 56 - 71 | 12 - 18 | 10 - 22 | 225 °F (107 °C)[81] |
| Olive | 14.00 | 72.00 | 14.00 | - | - | - | 380 °F (193 °C)[78] |
| Palm | 49.300 | 37.000 | 9.300 | - | 10 | 40 | 455 °F (235 °C)[82] |
| Peanut | 16.900 | 46.200 | 32.000 | - | 32 | 48 | 437 °F (225 °C)[79] |
| Safflower (>70% linoleic) | 8.00 | 15.00 | 75.00 | - | - | - | 410 °F (210 °C)\] |
| Safflower (high oleic) | 7.541 | 75.221 | 12.820 | - | - | - | 410 °F (210 °C)] |
| Soybean | 15.650 | 22.783 | 57.740 | 7 | 54 | 24 | 460 °F (238 °C)] |
| Sunflower (<60% linoleic) | 10.100 | 45.400 | 40.100 | 0.200 | 39.800 | 45.300 | 440 °F (227 °C)[] |
| Sunflower (>70% oleic) | 9.859 | 83.689 | 3.798 | - | - | - | 440 °F (227 °C) |
| Fully hydrogenated | |||||||
| Cottonseed (hydrog.) | 93.600 | 1.529 | .587 | .287 | |||
| Palm (hydrogenated) | 47.500 | 40.600 | 7.500 | ||||
| Soybean (hydrogen.) | 21.100 | 73.700 | .400 | .096 | |||
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| Olive tree in Portugal |
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