The better an agricultural product is beneficial used, the more its production increases.

Olive oil, which has a higher value compared to other vegetable oils, has superior organoleptic, physical and chemical properties. These superior qualities must be preserved in the process of obtaining olive oil.

Production of good quality olive oil is possible by fully complying with the conditions stipulated by the technique in processing stages . In the production of oil, even in the most primitive form of processing, the olive goes through various stages until it is processed. And each stage has an effect on the quality of the oil.

Therefore, even processing olives from the same genotype and the same region into olive oil with different processing techniques can cause significant variations in the qualitative properties of the oil produced.

Olive oil processing systems, which have been in continuous development since ancient times, are still changing and developing today. But there is a common point in all of them that the oil is extracted using only mechanical or physical methods.

Olive oil is one of the rare oils that are consumed as virgin without being refined. Details of traditional olive oil processing technologies can be found in the literature. Processing techniques currently in use will be examined in detail.

Harvest period and harvesting style of olives are factors that significantly affect the quality of the final product. For the fruit, the "Maturity Index" is calculated and the harvest time is decided. Harvesting can be done on the tree, by hand stripping, mechanical harvesting and ground picking. It is very important that the "bottom olives" collected from the ground are not mixed with the actual harvest (top olive).

They should be transported and kept during and after harvest. The olives should be preserved very well until they begin to be processed, protected against mechanical damage, overheating and microbial spoilage.

 

The main processes applied in obtaining olive oil can be summarized as follows:

1.     Acceptance to the facility: Olive purchase is made through cooperative organizations in some European countries. Acceptance to the facility  is made according to the maturity and durability criteria of the olive. With the determination of these, olive oil suitable for the desired quality will be processed with the raw material available.

The importance of the purchasing process becomes apparent, especially considering the difference between the bottom olives falling from the tree.The oils obtained from the olives collected from the branch.

2.     Leaf separation and washing: The processing of olives into oil at the facility begins with leaf separation and washing. After harvest, foreign materials such as leaves, stones and soil are carried by olives. Olives must be cleaned from these foreign substances in order to obtain good quality oil and to eliminate any malfunctions that may occur in the machines.

In order to wash 100 kg of olives, 10 to 100 kg of water is spent depending on the condition of the raw material.

3.     Crushing - Grinding process: The crushing process is important both physically and chemically. Because the extraction of olive oil from the olive tissue starts crushing and grinding of the olives. The aim is to break down the fruit flesh cells to remove the oil from the intracellular spaces.

Stone mills and metal crushers are used in crushing and grinding processes. Stone mills are a crushing and grinding method that has been used for many years.

4.     Kneading (Malaxation): After the olive is crushed, it must be kneaded, especially when metal mills are used. This process is important in separating the solid / liquid phases and preparing the dough. The purpose of kneading is to help the oil droplets to become larger drops in a continuous phase and increase the free oil percentage by breaking the oil / water emulsion.

5.     Separation of phases: Various methods are used to separate the liquid phases (oil and black water) from the olive paste from the solid phase:

a. pressing with strong pressure, b. centrifugation, c. system based on surface tension difference (percolation) and d. natural resting (decantation) process.

5 systems are used in olive oil production:

a. Classic System - Dry System (super press)

b. Classic System - Water System (hydraulic press)

c. Modern System - Continuous Centrifuging System

d. Modern System - 3 Phase Continuous Centrifuging System

e. Modern System - 2 Phase Dry System (super press)

f. Modern System - Double Extraction (Sinolea ) System

Although a wide variety of technologies have been developed today, even the oldest systems are revised and used in order to meet different consumer expectations.

The facilities that adopt the ancient pressing system as a principle, and have improved their machinery and equipment with stainless steel. Materials deemed appropriate by good food practices, based on today's quality food processing rules, primarily work on the principle of "not getting tired" of olive oil.

Oil is tried to be obtained in its most natural form without exposing it to any accelerating phase. Olives are collected by hand as much as possible, generally based on early harvest.

In facilities, only crushing, kneading for a short time, pressing and natural decantation (phase separation) stages with the principle of density difference. There is no heat reinforcement at any stage. In this way, olive oil is almost obtained by the ancient method and it can be preferred by the consumers of trends such as healthy nutrition, organic products, boutique products.