Olive oil is a common cooking oil obtained from olives used all over the world, especially in the Mediterranean. The taste varies by region, altitude, time of harvest, process of extraction and other factors.
Vegetable oils can be edible or non-edible. The ones used for cooking are mostly derived from one particular plant source or may be a blend of two or more oils.
Source and Producers
Olive oil is extracted from olives (Olea europaea; family Oleaceae), a traditional crop of the Mediterranean region. Major producers of olive oil include countries in Southern Europe, North Africa and Near East. In Europe, the main producers of olive oil include Spain, Italy, Portugal and Greece.
The source of vegetable oil varies according to the type of oil or crop, and sources include the seed of a fruit and nuts.
Calories and Fat Composition
Olive oil contains 14% of saturated fat and 73% of monosaturated fat and considered the healthiest of all oils for cooking. One tablespoon of olive oil contains 120 calories.
Different vegetable oils have different percentages of saturated, monosaturated and polysaturated fat. Coconut oil has the highest amount of saturated fat (92%) and mainly used in desserts, and as shortening. Canola and sunflower oil have the least amount of saturated fats (6% and 9%, respectively), and contain a higher percentage of monosaturated fat (62% and 82% respectively), and is a preferred choice, only second to olive oil. One tablespoon of regular vegetable oil contains 120 calories.
These numbers are approximate; there is a slight variation depending upon the source of data.
Olive oil is used for cooking, is good for the skin, and has some uses for medicinal purposes as well, such as being used as a laxative or in the preparation of some medications. In some religions like Christianity and Judaism, olive oil is used as a symbol for healing.
Though vegetable oils are used for cooking, other uses include fuel, cosmetics and medicinal and other industrial purposes.
The three types of olive oil are extra virgin, virgin and pure olive. Extra virgin oil is the most expensive. This type comes from the first cold press, and has the lowest acidity levels (less than 1%) of the three types. Because of its perfect balance in taste aroma and color, it is used in dressings and also served with bread. Its taste and aroma is typical to the region it comes from. Virgin olive oil is also obtained from the first pressing of olives, but its acidity level is higher (up to 3.3%) than that of extra virgin. Pure olive oil is a term given to a blend of virgin and refined olive oil. Due to the blended nature of this type, it is less expensive and used in cooking involving high temperatures. Refined and lite olive oils undergo chemical reining methods, and are as healthy compared to the other types of olive oil.
The different types of vegetable oils include palm oil, soya bean oil, canola oil, pumpkin seed oil, corn oil, sunflower oil, safflower oil, peanut oil, grape seed oil, sesame oil, argan oil, rice bran oil and some others. These types can be broadly categorized into nut oils (cashew oil and hazelnut oil), oils from seeds (sunflower seed oil), and other sources.
The smoke point of oil is the temperature at which it starts burning. The use of light oils is recommended when cooking at high temperatures. The smoke point of olive oil is lower than regular vegetable oil and varies from 215° to 242° (extra virgin having a lower smoke point than the lighter version). The smoke point of vegetable oils vary and are higher for oils used for frying, like canola oil (smoke point 242°), and safflower oil (smoke point 265°).
Olive is known to be rich in vitamins and minerals due to its non-chemical mode of extraction. It is believed to decrease in the rate of heart disease due to its high content of monosaturated fatty acids such s oleic acids. This helps lower LDL and raise HDL levels, and makes the arterial walls more elastic. Its anti-oxidative properties (contributed by presence of polyphenols in the oil) also help lower the cholesterol level in the blood.
Vegetable oils like canola oil contain lower amount of saturated fat, and are less expensive compared to olive oil. Other highly flavorful oils such as sesame and coconut oils are used to impart flavor to special dishes.
All oils are best stored in cool and dry place, far from areas exposed to sunlight. Some oils must be used within 6 months after opening whereas others like olive oil last longer from 9 months up to 2-3 years. Oils like sesame and other unrefined ones should be stored preferably in cold storage, whereas saturated oils like coconut and palm oil can be stored at room temperature.