Olive oil
Olive oil, with the simplest definition, is the separation of the water and solid components of the olive fruit.
Olive oil, which does not cause any change in the oil content of the olive and is obtained only by mechanical and physical applications, is a freshly squeezed fruit oil, its natural triglyceride structure has not changed, it is raw, natural and pure.
It is liquid at room temperature (20-25°C), its color can vary from clear green to yellow, it has a unique taste and odour.
An average of 70% of the oil in the olive is found in the fleshy part of the fruit and the remaining in the kernel. The peel does not contain oil.
For ages, it has been the only source of vegetable oil in the nutrition of the people living in the Mediterranean basin. Natural olive oil (unrefined, extra virgin) has become the symbol of the "Mediterranean diet" or "Mediterranean Cuisine", together with wine, and is now a sought-after oil in different cuisines of the world. Studies in the peoples of the Mediterranean basin have shown that the consumption of natural olive oil reduces the likelihood of health problems such as hypertension, coronary heart disease, cancer, and age-related cognitive impairment. Longevity has been found to be associated with olive oil consumption. Regular consumption of olive oil throughout life is thought to have multiple beneficial effects on human health. It is one of the most researched oils in recent years, it is accepted as a functional food. Evidence-based research and inquiries on the phytochemical components and their bio-benefits continue.
Olive Oil Production - Separation of Oil from Olives
In the olive fruit, water and oil are in the state of emulsion (two liquids that are insoluble in each other as a mixture). Therefore, in order to obtain oil from olives, the oil must be separated from water and other solid components. The aim in the production of natural olive oil is to obtain an oil that can be consumed as food in its natural state without refining.
Other vegetable oils, most of which are produced from oilseeds, have to undergo a refining process. In order to make such oils consumable, the unwanted substances in the composition of the oil (stone, soil, dust, large molecules, oil-soluble and non-saponifiable parts of the oil, etc.) are removed by the refining process and the oil is tried to be purified, but without sacrificing the naturalness of the oil. this operation is not possible.
The process of separating the oil components in olives from the solid and water components consists of more than one step. In today's conditions, this action is carried out with the use of technological methods. The first step of the process is squeezing and blasting the olive together with its core by mechanical force. With this step, “olive dough” consisting of solids and fluids emerges, and the dough is kneaded for a while. In the next steps, only physical methods (pressing, centrifugation or cold percolation/selective filtration) are used to separate the oil from water and solid components.
During the whole process, there is no refining application in any of the steps. It does not contain any chemical intervention. When the oil separation process is completed, a refined vegetable oil -exposed to thermal and chemical treatments-like other vegetable-derived oils obtained from seeds, does not emerge.
At the end of the process, the oil separated into its visible solid components is turbid. This is because it still contains solid components, although it cannot be discerned by the naked eye. The oil is kept in steel tanks and under suitable conditions for a while, so that the particles that cause turbidity are allowed to settle to the bottom.
Classification of Olive Oil
1.Natural Olive Oil: It is the oil that can be consumed as food in its natural state, with a clear color that can change from green to yellow, with a unique taste and odor, obtained by applying only mechanical or physical processes at a temperature that will not cause any change in the natural qualities of olives. No food additives are added to natural olive oils.Natural olive oils are also divided into two parts as "suitable for direct consumption" and "not suitable for direct consumption".
Natural olive oils "suitable for direct consumption" are grouped under three categories:
Natural Extra Virgin Olive Oil: They are oils that do not have any defects in odor and taste, and the free fatty acidity -as oleic acid- is not more than 0.8 grams per 100 grams (maximum 0.8%).
Natural First Olive Oil: They are oils that may have very slight defects in odor or taste, and the free fatty acidity -as oleic acid- is not more than 2.0 grams per 100 grams (maximum 2%).
Natural Second Olive Oil: They are oils with tolerable defects in odor or taste, with free fatty acidity -as oleic acid - not more than 3.3 grams per 100 grams (3.3% maximum).
Natural olive oil "not suitable for direct consumption" is called "crude olive oil" or "lampant". Its free fatty acidity is over 3.3% in terms of oleic acid and/or it does not have the characteristics of natural olive oil in terms of sensory and characteristic features. It is an olive oil suitable for refining or technical use. It is not used as food.
2. Refined Olive Oil: It is obtained by refining -by heat and chemical treatment- of crude olive oil, which is not suitable for direct consumption, by methods that do not cause any change in the natural triglyceride structure, has a color in different shades of yellow, has a unique taste and odor, free fatty acidity in terms of oleic acid is 0 per 100 grams. Fats not more than .3 grams.
3. Riviera Olive Oil: These are oils that consist of a mixture of refined olive oil and natural olive oils that can be consumed directly as food, with a color varying from green to yellow, with a unique taste and smell, free fatty acid in terms of oleic acid, which is not more than 1.0 grams per 100 grams.
4. Flavored Olive Oil: These are oils obtained by diversifying olive oils by adding different spices, fruits and vegetables or substances containing their natural flavors, and the free fatty acidity (0.8% maximum) is not more than 0.8 grams per 100 grams in terms of oleic acid. The quality and purity criteria of flavored olive oils must comply with the criteria given for extra virgin olive oil.
Compiled by: Uğur Saraçoğlu (ugisaracoglu@yahoo.com.tr)
Resources:
1. World Olive Encyclopedia; International Olive Council; Fausso Luchetti, 1997.
2. Olive oil; Fahrettin Göğüş, Mücahit Taha Özkaya, Semih Ötleş, Eflatun Publishing House, 2009.
3rd Izmir Olive Symposium; In Search of the Immortal Tree/Don't Touch My Olive, 2-3 September 2015.