Years 6 | n. 52 | 24 April 2014
Technical Area > Olive & Oil

Filtered or unfiltered olive oil?

There is too much confusion about extra virgin olive oils around. Everybody pontificate about every aspect of oil production or quality. This is even worst when the issue is a technical aspect such as the oil clearness

by Luigi Caricato

How much is the clearness important? This is something that the consumers like a lot, since it is typically associated with cleanness. As a matter of fact, just after pressing the oil shows intrusions of water and solid particles: all these should be removed by proper decantation. This should be done before bottling the new oil. Nowadays a more practical approach is the oil filtering.

Even if traditionalists donít like this, filtering is nowadays a necessity for producers that what to sell their products on the market in bottles. This operation was absolutely normal and necessary in the past, since one of the main targets of the producers was to grant the oil of a long shelf life.

On the other side, when the oil was sold on tap, i.e. when it was still possible to sell oils in unlabelled and unsealed bottles, oil was naturally decanted, without any active filtration. Nowadays, even the smallest farms sell their oils packaged, hence nobody disdains filtration. This is just to be safer. Clean oil lasts longer.

The detractors of this practice, in particular in the last years, claim that it impoverish oils of its most noble components. E.g. biophenols. This class of molecules, poorly known by the public, are a vast class of molecules that, given their antioxidant properties, make extra virgin olive oil a very healthy and tasty product, for the nose and the mouth.

This is true, of course. But after filtration, oil biophenols do not disappear completely. As a matter of fact, just the 20% of them is lost by filtration. According to the detractors of this technique loosing these composts is pointless: their point of view cannot be underestimated. At this regard, there are different schools. However, it is fair to recognize that at this regard the world of research wasnít immobile and they experimented different possible solutions to this problem. Their work was aimed at minimizing the lost of these active and precious compounds, and nowadays some interesting alternatives to traditional filtration procedures are available.

It is not worth here describing the technicalities of the process, but it is important here to stress that is now possible to filtrate oil with inert gases. This innovation preserves the quality of the product. This is a technology developed in Italy by the Department of food Science of the University of Bologna. The results are surprisingly good, since not only this kind of filtration preserves oil from loosing biophenols, but it also protect the product from oxidation.

Then do not hesitate about new technologies. Letís get rid of old fears. It is important to look ahead since quality is in continuous evolution. Most of the oxygen dissolved in oil is now substituted by inert gases. Hence, oil we can buy nowadays is endowed with a longer life expectation. There is no reason now to refuse oil filtration anymore. History of oil goes on, everyday.

Tradition, without innovation in useless. It is pointless to keep an old idea claiming that in the deposit of the bottle there is a plethora of different particles. Oil filtration is good for the final product.

by Luigi Caricato
05 March 2012 Teatro Naturale International n. 3 Year 4