Shelf life and quality of olive oil filtered without vertical centrifugation

This study evaluates the effect of filter press filtration on the shelf life of extra virgin olive oil (EVOO). Olives were harvested and processed on the same day by a continuous industrial plant equipped with a hammer crusher, a vertical malaxator, and a decanter. One part of the oil obtained was bottled (cloudy oil). The other part was filtered (using a filter press) directly after decanting and manually bottled using the same procedure (filtered oil). All samples were stored in a purpose-built chamber and periodically analyzed. The results show a less degraded phenolic fraction in the filtered olive oils. In fact, compounds such as Tyrosol and Hydroxytyrosol, which are the final product of hydrolysis of secoiridoids, remain stable in filtered oils and increase in cloudy. Moreover, filtered olive oils have a better sensory profile than the cloudy along the shelf life. These data are confirmed by the GC-MS analysis. The results confirm that filtration is essential in order to maintain the nutritional characteristics of the oil, and slow the onset of the main defects.