Chemical characteristics
The chemical structure and behaviour of the olive oil of Lesvos
Virging Olive Oil of Lesvos
Virgin olive oil is a natural oleaginous substance of a complex structure, an exclusive result of the Mediterranean natural environment. The manner it is produced (crushing the olive fruit and pressing the oil from the olive pulp) allows it to have the name “Olive juice”, as it bears the taste, aroma and composition of the olive. The particular features of the Olive Oil of Lesvos have been officially recognised by the European Union and it has been registered as a product with a Geographical Indication. In a breakdown of the composition of Virgin Olive Oil of Lesvos it is important to make a distinction between macro – ingredients (~99%) and micro – ingredients (~1%). Included in the macro – ingredients are the fatty acids, which are mainly present in the form of triglycerides. Their composition depends on the olive tree variety, the main varieties cultivated in Lesvos being “Kolovi” and “Adramytiani”.
Breakdown of fatty acid percentages and maximum levels:
I.
|
Olive oil from Lesvos, |
II.
|
Greek olive oil, |
III.
|
Range of maximum levels of fatty acid percentages as regulated by the International Council for Olive Oil. (ICOO), |
IV.
|
Sunflower Oil |
Main fatty acids
|
Olive oil from Lesvos*
|
Greek Olive Oil
|
ICOO Range of Maximum levels
|
Sunflower Oil
|
Oleic (monounsaturate) |
74,6
|
75,8
|
55-83
|
14-35
|
Linoleic (polyunsaturate) |
10,8
|
8,8
|
3,5-21
|
55-75
|
Palmitic (saturate) |
9,4
|
10,5
|
7,5-20
|
3-10
|
Stearic (saturate) |
2,7
|
2,5
|
0,5-5
|
1-10
|
Linolenic (polyunsaturate) |
0,8
|
0,6
|
0,0-1,5
|
Over 0,3
|
Palmitic – oleic (monounsaturate) |
0,6
|
0,8
|
0,3-3,5
|
0-1
|
Source: studies made by National Chemistry Laboratory on Greek olive oil 1991-92 and 1993-94.
The micro-ingredients include Vitamin E, phenolic and polyphenolic compounds (colouring substances with intense antioxidizing activity), sterols, alcohols, colouring agents (carotenoid substances, small quantities of chlorophyl), squalene etc. Chemical analyses to certify the quality of the oil are carried out on a regular basis by all the packaging factories on the island, and of course by the State Quality Control Services. Thus, the following macroscopic and organoleptic features are characteristic of Lesvos olive oil:
-
Liquid texture (low glutinocity – smooth taste), due to the relatively high level of unsaturates, as can be seen in its fatty acid composition. The more saturate lipids an oil contains, the thicker it is; while an increase in the degree of unsaturation renders the oil more fluid.
-
Light golden colour due to the low content of chlorophyl (a green colouring agent found in vegetables). It has been established that chlorophyl speeds up the oxidation of olive oil when exposed to light. Low chlorophyl content protects Lesvos olive oil from rancidity.
-
The distinctive aroma and taste of the Aegean olive.
.
This text is an extract from the booklet “The olive oil of Lesvos” of Vassilis Zambounis, that was published by the Hellenic Foreign Trade Board in collaboration with the Chamber of Lesvos.
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