Olive Tree - Olive Oil

History of Olive Tree

The olive tree first appeared thousands of years ago in the Mediterranean Basin, and from there it spread to all neighbouring countries.

It is believed that ever since the Neolithic Age, collection of both edible and wild olives (Olea europaea oleaster) were practiced in the Aegean area. The oldest samples of olive pollen found so far can be dated to the end of the Neolithic Age and they come from Crete and Boiotia.

50000 years old fossilized leaves of the European Olive Tree were discovered on Nisyros, Cyme and Santorini.

According to Ancient Greek Mythology, the olive tree was a present of goddess Athena to the city of Athens, when a competition between her and god Poseidon took place in order to decide the patron deity of the city. When the competition started, god Poseidon struck the sacred rock of the Acropolis hill with his trident causing a spring of salty water to emerge. This spring was known as the Sea of Erechtheus. Athena, with her turn, struck the rock and an olive tree full of olive fruits sprang, which was regarded as a promise of glory and prosperity for the city.

Τα αρχαιότερα δείγματα συστηματικής ελαιοκαλλιέργειας και παραγωγής λαδιού προέρχονται από την Ανατολική Μεσόγειο και μάλιστα από την Παλαιστίνη.

The stone presses, which were discovered at the area of Haifa in Israel and can be dated to the 5th millennium BC, are related to olive oil production.

In all likelihood, the Phoenicians were the first to distribute the olive tree cultivation to the Mediterranean Basin and also the first to produce olive oil by using the same technique as the Egyptians who extracted oil out of seeds.

The clay tablets found in the Mycenaean palaces of Crete and mainland Greece provide us with information about olive tree cultivation, and olive oil production and distribution. These tablets are written in the first Greek writing, which is a syllabic script conventionally named Linear B.

Η ελιά από αρχαιοτάτων χρόνων εμφανίζεται στους μύθους, στις παραστάσεις και στην ιστορία των λαών στις χώρες που φύεται. Αποτελούσε ανέκαθεν σύμβολο ευημερίας, ειρήνης, γονιμότητας και ευφορίας. Για να καταλάβουμε την κοινωνική σημασία της πρέπει να θυμηθούμε ότι στην αρχαία Ελλάδα οι νικητές των Ολυμπιακών αγώνων στέφονταν με ένα στεφάνι ελιάς και έπαιρναν σαν δώρο ελαιόλαδο.

From an early period, the Greek nation was associated with the olive tree and olive oil. They were both connected with many aspects of life and they were a part of the Greek social, economic and artistic expression. Soon, the Greeks started more and more techniques of usage, and they discovered both the therapeutic and cosmetic properties of olive oil. It is still used even today in many beauty products.

The olive tree is considered a blessed tree and every part of it can be exploited. Today, apart from its fruit, wood and leaves, the olive processing waste can be also used in industry.

Olive groves

The olive is an evergreen and age-old tree. Olive cultivation is limited to the two temperate zones and mainly to the Mediterranean region which has 98% of the world plant potential and production. Crop care is scarce and therefore survives in particularly inaccessible areas.

The European olive tree (this is the olive tree which produces olive oil) has many varieties. There are about 130 varieties of olive trees with 50 of them being the most well known. Some of these varieties are the result of a long developing and adaptation process in the same micro-climates where other species grew due to lab development. Depending on the variety of the plant, olive trees can be categorised as small-fruit, medium-fruit, large-fruit and ornamental (non-fruiting).

Thassos has a Mediterranean climate favoring the cultivation of olive trees, both in flat and mountainous areas, and enabling the production of fruit during the winter. In the area of there are olive trees more than 700 hundred years old.

The dominating variety of olive tree on Thassos is called throubolia or Thassian olive. It is mainly cultivated on Thasos and other areas like Attica, the Aegean Islands (Chios, Samos, Naxos) and on Crete. It belongs to the middle-fruit variety of olive trees and it is suitable for consumption. The fruit is of medium size with an average weight of about 3-5gr, and an oil capacity up to 25% of the highest quality. The Thassian olive (throuba) has the ability to loose its bitterness by itself while maturing on the tree and therefore it is considered a unique delicacy for the Mediterranean table.

Olive Oil & Health

Olive oil is the basis of the Mediterranean food chain, which has proven to be a model of proper and healthy nutrition and a factor of longevity.

The beneficial properties of olive oil, lie in its chemical composition. Olive oil consists of oleic acid, linoleic acid, palmitic and stearic acid and even phytosterols in a very small percentage. Linoleic acid is of great importance for our health, since the lack of it leads to a number of health problems, such as developmental delay, metabolic disorders etc.

Olive oil contains 60-80% monounsaturated fatty acids which are much more resistant to oxidative processes than the polyunsaturated fats contained in seed oils.

Here, at the organic olive mills of Thassos, we produce the Cardiofilo which literally means in Greek “friend of the heart”. Thus, one may understand the beneficial properties of olive oil for the human cardiovascular system.

The nutritional composition of olive oil is excellent because it contains few saturated and plenty monounsaturated and polyunsaturated fatty acids.

Saturated 10-12,5 %
Monounsaturated 72-77%
Polyunsaturated 17,0%

It has been proved that monounsaturated fatty acids, and in particular the oleic acid, protect from coronary heart disease because they reduce the levels of low density lipoproteins or LDL (“bad cholesterol”), and at the same time they can increase the levels of HDL (“good cholesterol”) which protect the human body system from arteriosclerosis.

Olive oil is also a rich source of the fat-soluble vitamins A, D, K and especially vitamin E, which protect our health from several types of cancer (for example colon cancer and breast cancer) and osteoporosis. These vitamins together with the valuable polyphenols of olive oil can be found only in virgin olive oils because in the refined olive oils they are almost completely destroyed. In addition, due to its antioxidant action, olive oil delays cell aging, helps with digestion and calcium absorption and advances skin health.

Studies related to the beneficial properties of olive oil during child growth show that normal amounts of olive oil provide the perfect balanced intake of fatty acids for the natural calcification of the bones. It has also been suggested that low intake of lineloic acid may result in growth delay and cause skin, hepatic and metabolic disorders. In conclusion, it becomes obvious that olive oil, and especially organic olive oil deriving from biologically cultivated olive trees and therefore containing no traces of any chemical substance, forms an integral part of our children’s ideal diet.

Olive oil is preferably consumed raw, so that our body system can absorb all its nutritional substances. But even when frying, olive oil is considered the best oil because of its durability against high temperatures and oxidation.

It is beyond any doubt that olive oil protects human health. In November 2004 an FDA directive (Docket No 2003Q-0559) was published in CFSAN/Office of Nutritional Products, Labeling and Dietary Supplements November 1, 2004, which suggests that 23gr. (two teaspoons) of olive oil protects from coronary diseases, especially if it contains a high percentage of monounsaturated acids. The Forest Preserve of Cook County Illinois suggests that the best salad olive oil is the yellow.

The main types of olive oil

Not all olive oils are the same! There are many types with differences in quality and price.

The basic properties defining a quality olive oil are the following:

Acidity, which is expressed as free oleic acid. Less acidity is better and if the percentage is less than 0.8%, the olive oil is called extra virgin whereas if the percentage is between 0.9% and 2%, it is called just virgin.
Colour, which is related to fat-soluble colouring substances (chlorophylls, xanthophylls, carotenoids). According to the Forest Preserve of Cook County Illinois the best salad olive oil is the yellow.
Based on the oxide determination, the peroxides must be less than or equal to 20.
However, the most basic property of a quality olive oil lies in the organoleptic elements, which need to be those in order to make a proper fruit juice. These are:
- The natural perfume of olive which indicates than no processing for removal of unpleasant smells took place. It also means that the olive harvesting was executed at the right season and that the processing of the fruit was done with the right conditions as described below.
- The bitterness which derives from oleuropein and indicates that the olives were not too ripe when they were harvested for becoming oil.
- The piquant (burning sensation) which derives from the essential oils and other volatile substances of the olive fruit and indicates the appropriate olive oil preservation conditions.

The production of quality olive oil requires a procedure according to specific regulations which are related to:

The olive tree cultivation and especially the tratment of diseases, mainly the Olive Fly. It is self-evident that the olive fruit which has been destroyed by the larva (warm) of the Olive Fly or by other diseases cannot be good. The main problemof an olive fruit infected by the Fly is the relatively high amounts of acidity and bad taste.
Harvesting. The olive fruit harvesting is done from the end of October until the end of January. The best period is considered when the olive fruit is 25% green and 75% dark (not black). The maturation of the olive fruit is accompanied with blackening and simultaneously with reduction of the oleuropein, a substance which gives bitterness to the olive oil and it constitutes one of the qualitative properties of a good olive oil. Harvesting must be done by hand or with mechanically or manually operated toothed devices resembling a comb, in order to avoid bruising the olive fruit, which causes oxidation reactions that undermine the quality of olive oil. The fruits that fell from the tree due to bad weather conditions must not be processed into edible olive oil because they have a problem (they can be rotten, infected by the olive fly etc.)
Transportation and storage. The fruits of the olive tree fall on the olive-sheets, and after removing the branches, they are placed together with their leaves in plastic crates, in order to be well-ventilated. The crates must be placed in a cool place and afterwards they need to be transported to the olive mill for processing. By following this procedure, we shall have healthy fruits for processing. Placing the olive fruits in sacks into the storeroom or storing them in piles is forbidden because the temperature rises (the olive is heating up) and the fermentation process increases.
Processing the olive fruits. This needs to be done at the latest within 3-4 days after harvesting because prolonging time will result to the fruit alteration. The appropriate processing procedure (apart from the processing manner) needs to follow specific rules:
- The fruits are transported via a CONVEYOR BELT made of material suitable for carrying food to the OLIVE REMOVE-LEAF MACHINE, where the leaves and dust can be removed.
- When the olives reach the olive mill, they are placed manually and not mechanically in a stainless steel OLIVE FUNNEL.
- Next, the fruits are transferred to the OLIVE WASHER where they are washed with potable water in order to be clean for processing. Washing the olive fruit is very important, because existing dirt can be transferred to the olive oil where it remains. Afterwards the fruits are weighted on Electronic Scales and then they are placed on the olive loader
- The fruits are now led to the OLIVE GRINDER (it resembles a meat grinder), where they are roughly crushed. Afterwards, they are temporarily stored in the first stage malaxer and then they are transferred to the STONE-MILLS where the olive flesh is further crushed, in order to release the aromatic and other substances such as essential oils. It is common knowledge that olive oil and other substances are found in the flesh of the olive in the form of droplets and that crashing the olives in the GRINDER cannot release these substances. This can be achieved only by using stone mills.
- After pressing, the olive paste is led to the OLIVE MALAXERS by an olive paste loader where it is stirred at a low temperature in order to be ready for
- The 2-phase separation process in the DECANTER which separates the paste into two elements, the olive oil (oil-juice) and the pomace. This method does not need water while processing the fruits and therefore there is no liquid waste (oil-moist or oil-residue) which in fact carries away many useful elements of the oil juice. The process of oil extraction by placing the paste into sacks, and afterwards pressing it, is problematic because it raises questions regarding the sacks’ cleanness. Furthermore, the sacks retain oil which is oxidised and transferred to the produced oil.
- Afterwards, the oil juice is led to the OIL-SEPARATOR for removal of small amounts of water and few solid admixtures (mud). It is important in this stage to wash frequently the separator so to minimize oxidation.
- After this point, the product is weighted and led to the Oil-tanks of the industrial unit which must be stainless and impermeable. The tanks need to be cleaned from all existing residue so to minimize anaerobic oxidation. The oil tanks need to be in a well-ventilated area where the temperature is not too low or too high.
- After remaining there for a month, olive oil is transferred to a paper filter where floating particles and water are retained. Afterwards olive oil bottled bottled in glass bottles or it is placed in metal containers.
- Olive oil must be kept in a dark place because the sunlight accelerates oxidation. The temperature needs to be between 15 and 25 Celsius degrees for the same reasons.

Here, at the ORGANIC OLIVE MILLS of Thassos we follow this procedure, as described above, and we feel that we produce an excellent product.

The main types of olive oil are the following:

Extra virgin olive oil: olive oil whose acidity level expressed as free oleic acid is not more than 0.8%.
Virgin olive oil : olive oil whose acidity level is not more than 2%.
Lampante virgin olive oil : olive oil with bad taste and smell or with the highest acidity level expressed as oleic acid (higher than 3,3g/100g oil). The olive oil of this type is destined for refining or for industrial use
Refined olive oil : olive oil obtained after refining virgin olive oils
Olive oil or pure oil : a blend of edible virgin olive oils and refined olive oils.