Olive oil is a liquid fat derived from olives (Olea europaea fruit; family Oleaceae), a common Mediterranean Basin tree crop. The oil is produced when the whole olives are pressed. It is widely used in cooking, frying food or as a dressing for salads. This is also used as a solvent for the traditional oil lamps in cosmetics, pharmaceuticals, and soaps, and has additional uses in some religions. There is limited evidence of its potential benefits to safety. In Mediterranean cuisine, the olive is one of three main food plants; the other two are wheat and grapes. Since the 8th century, BC olive trees have been planted around the Mediterranean.
Today, Spain is the largest olive oil producer followed by Italy and Greece. Regional consumption per capita is, however, the largest in Greece, followed by Spain, Italy, and Tunisia. Consumption is much lower in South Asia, North America, and Northern Europe but steadily rising.
The composition of the olive oil varies with the cultivar, altitude, harvest time and method of extraction. This mainly consists of oleic acid (up to 83%), with smaller amounts of other fatty acids including linoleic acid (up to 21%) and palmitic acid (up to 20%). Extra virgin olive oil is expected to have a free acidity of no more than 0.8 percent and is considered to have desirable flavor.
The modern olive tree most likely originated in ancient Persia and Mesopotamia, spreading in the Mediterranean Basin to Syria and Palestine, where it was cultivated and later introduced to North Africa. Several scholars concluded that olive growth originated from the Ancient Egyptians. Olive trees were introduced to the Americas in the 15th century AD when cultivation began in areas that enjoyed a Mediterranean-like climate such as Chile,
Argentina, and California.
How Olive Oil is made?
The olives were pressed by early oil producers by crushing them between huge cone-shaped stones as they slowly turned on a granite foundation. Most factories today use hydraulic presses which exert hundreds of tons of pressure to separate the oil from the olive paste. Spain and Italy are the main commercial olive and olive oil producers. Behind them, Greece is nearby. However, California, Australia, and South Africa are emerging as leaders in the industry. Many wineries cultivate olives to compensate for bad wine harvests. Ironically, missionaries planted olive trees in California in the 1800s which developed an excellent grade of olive oil by the turn of the century. The market demand, however, was low, so the trees were uprooted, and grapevines were planted instead.
The focus on good nutrition and a fascination with the so-called Mediterranean diet in the late twentieth century has resulted in a revival in the olive oil trade. Olive oil is said to be monounsaturated and more suitable for human consumption than maize and vegetable oils. When mixing with beeswax, the oil is also marketed as a dandruff reliever and a homemade lip balm. The US and Canada consumed 147,600 tons (150,000 metric tons) of olive oil a year in the late 1990s. Demand still exceeds supply, and prices rose sharply in the 1990s.
Olive oil is the primary ingredient in oil that is derived from ripe olives. On the olive trees, small flowers appear in the late spring. Wind pollination allows the olives to blossom, which hit their peak oil content about six months later. Workers have knocked the fruit from the trees with long-handled poles since ancient times. Over the years, the mechanism hasn’t changed significantly. Traditional poles are comparable to rakes. The nets were initially placed beneath the tree to capture the dropping olives. Most producers now use plastic coverings to cushion the fall and allow for easier, cleaner collection. One quarter (0.95 l) of the highest quality extra virgin olive oil needs 2000 olives. The only ingredient applied to extra virgin olive oil in the warm water used to flush away the bitterness of the olive, caused by oleuropein.
Olive oil extra virgin contains no more than 1 percent oleic acid. Pure olive oil is often mixed with extra virgin olive oil which results from the second pressing. Commercial grades, or non-edible grades, are placed through a cycle of grinding that may leave traces of soda solutions and bleach carbons.
The Manufacturing Process
Collecting and grading of the olives
After the mature olives have been peeled from the trees, they are picked by hand for weeding out unhealthy olives. The olives are divided into categories by plumpness, ripeness, and quality. The olives are then taken to the press and processed for a short period of time, from a few hours up to a few days.
Wash and Cook the Olives
The olives are rinsed in cold water and moved between rollers or continuous hammers along a conveyor belt. Also named the olive crusher, this device breaks down the cells and de-stones the olives. It may be necessary to pass the fruit through the mill a second time depending on the durability of the skin of the olives and the stage of maturation.
Creation of an olive paste by malaxing
In ancient times, a simple mortar and pestle pounded the olives into a paste. The idea was applied until the stone mortars were large enough to require slaves or packing animals for their service. The milled olives migrate from the mill into vats in the modern method, in which slowly turning blades churn the olives into a homogenized paste.
Cold-press the olive paste for oil extraction
- Through placing the paste in a hydraulic press, the oil is removed. The olive paste is spread evenly over hemp pressing bags or disks covered with synthetic fibers. Approximately 9-13 lb (4-6 kg) of paste is contained in each bag or disk. Between 25 and 50 bags or disks are placed on a plate for pressing. Plate guides are inserted in five to six sacs at intervals. The plates serve to keep the stack balance and to evenly distribute the weight. A piston pushes up against the plate, and the oil gradually flows into tubes that are inserted through the pressing sacs. Inside the pressing sacs remains the solid material.
- The word cold-pressing refers to the fact that the oil is extracted without heating the paste and the purity of the oil is further ensured. The oil represented is a reddish mixture of the oil and the vegetable water found therein. This is the oil that gets the name “extra-virgin” olive oil. The paste is stripped from the containers, going through several more presses to collect the remaining lesser grades of crude.
Separating the oil from the vegetable water
The oil and water mixture was initially held in vats until the oil rose to the top and was skimmed off. Some fermentation was inevitable, influencing the olive oil’s taste and odour. Today the separation is done quickly by pumping the mixture into a centrifuge. The centrifuge consists of a revolving drum and an auger, which is rotated at great speed on the same axis. Thanks to the varying densities of the oil and vegetable water, the centrifuge push them apart and into different receptacles.
Storing and packaging the oil
- The oil is stored in subterranean vats until it is fit for shipping. On an assembly line, the oil will then be canned or bottled. Cans or dark-tinted bottles should retain the olive oil deep-green color intact. Oil placed in clear-glass bottles will fade to a yellowish-green. However, the flavor is not affected.
- In many instances, the olive oil distributors buy and rebottle the olive from the farmers. Packaging has become more ornate as the olive oil has grown in popularity. Buying olive oil in unusually shaped bottles overlapped with netting or rope is not unusual. In addition, some packagers hire professional artists to design their labels.
Types of Olive Oil
Extra Virgin Olive Oil
Extra Virgin Olive Oil is the best olive oil quality with a maximum acidity of 1%. It has a full-bodied flavor of olive fruit and a nice, spicy characteristic typical of freshly pressed olive oil from ripe olives harvested.
Virgin Olive Oil
Virgin olive oil is typically slightly darker in color and has a higher level of acidity ranging from 1 to 4%. Because of the pressing of some over-ripe or bruised olives in the extraction mix, it is a lesser quality oil.
Pure Olive Oil
100% or Pure Olive Oil is olive oil that has undergone heat and chemical refining to remove impurities and then blended with Virgin Olive Oil to add some olive color and mild flavor.
Pomace Olive Oil
Olive Pomace Oil is made from the refining of the depleted olive paste left from the process of extraction. This refined oil is then combined with Virgin Olive Oil to give some olive flavor back.
Olive Oil Health Benefits
1. Olive Oil is Rich in Healthy Monounsaturated Fats
Olive oil has a high content of monounsaturated oleic acid. It is known that this fatty acid has many beneficial effects, and is a healthy choice to cook.
2. Olive Oil Contains Large Amounts of Antioxidants
Antioxidants are filled with extra virgin olive oil, some of which have strong biological effects.
3. Olive Oil Has Strong Anti-Inflammatory Properties
Olive oil provides inflammation-fighting nutrients. These include both oleic acid, and oleocanthal antioxidants.
4. Olive Oil May Help Prevent Strokes
Several major studies show that people who eat olive oil have a significantly lower risk of stroke, the second-largest killer in developed countries.
5. Olive Oil Is Protective Against Heart Disease
The extra virgin olive oil has many heart health benefits. This lowers blood pressure, protects “poor” LDL cholesterol particles from oxidation and increases blood vessel function.
6. Weight gain and obesity are not associated with olive oil
Olive oil use doesn’t seem to increase the likelihood of weight gain. Moderate intake could even help weight loss.
7. Olive oil can fight the disease of Alzheimer’s
Some studies suggest that olive oil may combat Alzheimer’s disease, but more research is needed.
8. Olive oil may reduce the risk of type 2 diabetes
All observational studies and clinical trials show that olive oil will reduce your risk of type 2 diabetes combined with a Mediterranean diet.
9. The Olive Oil Antioxidants have anti-cancer properties
Preliminary evidence indicates that olive oil may lower the risk of cancer but further studies are needed.
10. Olive Oil Can Help Treat Rheumatoid Arthritis
Olive oil can help to reduce rheumatoid arthritis pain and swelling in the joint. Once combined with fish oil, the beneficial effects are considerably enhanced.
11. Antibacterial properties of olive oil
Extra virgin olive oil has antibacterial properties and is known to be especially effective against Helicobacter pylori, a form of bacterium that can cause ulcers of the stomach and cancer of the stomach.
The difference between filtered and unfiltered oils
Extra virgin olive oil may be consumed either in filtered or unfiltered form. Filtration is the process of removing small bits of olive fruit from the oil. Unfiltered oil gets dusty until it settles down. Many find unfiltered oil to be better because of the fruit’s added flavor while others claim it shortens the shelf life of the oil. It is, in the end, a matter of personal preference.
Olive Oil Quality
The popular health benefits and olive oil flavor depend on many factors, and if you’re interested in the quality of olive oil, there’s a lot to learn. Sadly, what the bottle says you can’t trust, and the only way to learn good olive oil from poor is to know what to look for and learn how to taste it.
How To Taste Olive Oil
The best way to judge its consistency is to degust olive oil straight. Pour a little into a small glass, fill the bottle with one hand, and cover with the other. Now put your nose in the glass to taste the flavors. It will hopefully remind you of things such as new olives, trees, bananas and apples. Hay, straw, vinegar, mud and mustiness are some of the aromas that suggest an olive oil has gone bad.