Did you notice how many different shades of oil colors exist since green deep passing through the yellow sometimes arriving at a color so light that it almost seems transparent . The oil does not have a single color and above all the color does not determine the goodness of the product. If anything, it identifies the taste difference and the type of cultivar, the origin, the quantity of chlorophyll, the level of carotenes, the soil on which the olives were grown and their state of ripeness.
Believing that the more or less intense color of the oil determines the quality of the oil itself is therefore a false belief. To confirm how much color can be irrelevant in this sense, think that during the panel tests the oil is placed in dark glasses so that the shade does not determine its evaluation.
Rather, turbidity And clarity are elements to be taken into consideration when it comes to the quality and color of the oil. Features that in addition to determining one darker or brighter shade , identify whether or not there was the filtration of the product. Again, consumers are used to thinking that cloudy oil is more genuine and less refined. This is partly true, but as long as you meet certain conditions. One among all, the retention time . This is because the crude oil , if not consumed in a short period, it could give rise to the formation of deposits on the bottom and therefore to the fermentation of the same. Circumstance to be avoided. The reason is related to the amount of acids present in the oil. For example, the Mediterranean oils and especially the Italian ones, have a high concentration of monounsaturated acids that allow the water microparticles to remain in suspension for longer, resulting in fewer unwanted formations. Contrary situation for Tunisian oils.
Now let's see what the different ones are elements that help define the colors of the oil.
Carotene and chlorophyll
I'm natural substances that color the olive oil during processing. The first ones turn from yellow tol red / orange , while the latter have a coloring green . In addition to determining its color, these pigments are useful for preserving the oil and for their antioxidant action.
Often both are used strategically by producers to make the oil more attractive to consumers. We speak above all of the synthetic chlorophyll , added during the pressing of the olive to ensure that the oil acquires a bright green color. Another practice implemented to achieve the same color is the use of olive leaves (which contain chlorophyll) in the pressing. The result is a captivating nuance at the expense of the taste that remains much more bitter.
Carotenes And chlorophylls they are also directly linked to the state of ripening of the olives that are used. We find high levels of chlorophyll in underripe olives. The young oil is therefore very green. However, this color varies with the passage of time due to the deterioration of the chlorophyll itself. The upper hand is thus taken by the carotenes which fade to yellow and of gold the oil.
Cultivar
Also there agricultural variety affects coloring. In Italy alone there are more than 500 different cultivars. Depending on the type of olive, the pressing takes place at different stages of maturation.
Two typical types Apulian I'm there Coratina and the Ogliarola . The first, being squeezed at the beginning of maturation (where the chlorophyll level is higher), gives an intense green oil. Ogliarola, on the other hand, has a golden yellow color with light green shades.
In central Italy, more precisely in Tuscany and Umbria, the most widespread cultivar is that of Moragliolo . The color of the oil deriving from these olives is green with varying degrees of intensity.
The olive Taggiasca , typical Ligurian, is harvested during its full maturation so the resulting oil tends to pale yellow.
As a rule, the young olive returns a greener oil than a mature olive, which instead gives life to a more yellow oil. This is because the color of the not yet ripe fruit is usually green.
Geographical area: climate and terrain
The cultivar type is also related to the ground and al climate of geographic area where olives are grown. Humidity, rain, temperatures and soil particularly affect the shades of the oil.
The mild climate of the north it gives rise to cultivars for oils with a yellowish color. The center Italy welcomes the cultivation of olives on the hills and at the foot of the mountains surrounded by a temperate climate and mitigated by the sea from which a greener oil is derived. The south Italy has a dry and warm climate with clayey and calcareous soils, which are also excellent for green-colored oils.
Processing
The first important distinction is found between refined oil and unrefined oil. Artificial, too bright or too dull shades are a first clue. Through the high temperatures of refining, the oil loses its classic color turning towards a lighter shade, sometimes tending to transparent . Often this operation is also carried out to obtain a greater volume of product. Obviously the quality is lower than unrefined oils.
As we said earlier, even the degree of ripeness affects color. Ripe olives yellow oil, unripe olives green oil. Often, however, the olives are pressed when they are completely ripe, even if they lose some of their organoleptic properties, because the yield of unripe olives can be less than 50%.
storage
We have already talked about how conservation can change the appearance of the oil in terms of turbidity and residues. But not only. The color is also affected by the ways in which oil is preserved. Have you ever wondered why the bottles of oil they are dark in color To protect the contents from sun exposure. Sun and heat , Besides nightfall the color of the oil, affect the chemical composition causing a oxidative rancidity .
On the contrary, too much cold it may cause color spots White . In this case the product does not suffer damage with respect to quality. The white traces are due to the triglycerides that make up the oil (specifically palmitic and stearic acid). By bringing the oil back to room temperature, the white dots will tend to disappear.
The Advice is therefore to consume the oil within 12/18 months of extraction, away from the sun and sources of heat, at a temperature between 13 and 17.°.
Source:oilevo.eu
