STABILITY OF THE SENSORY QUALITY OF VIRGIN OLIVE OIL DURING STORAGE: AN OVERVIEW

The storage conditions of bottled or tank-stored virgin olive oil, as well as all the agronomical and technological variables of the processing stages, are particularly relevant for preserving the highly valued organoleptic quality of this product. All the efforts made in the olive grove and in the oil mill to produce virgin olive oil with good sensory characteristics can be undermined if improper storage conditions are used. In particular, it is necessary to protect the oil against lipid oxidation which can have many deleterious effects on the quality of virgin olive oil, including the formation of unpleasant organoleptic characteristics, the drastic reduction of the bouquet and taste notes as well as the reduction of naturally-occurring antioxidant compounds and therefore shortening of its the shelf life. The oxidation process during storage is known and involves changes to both the major and minor components of virgin olive oil. To slow down the oxidation rate during storage, certain factors such as the presence of oxygen and traces of metals, exposure to light and the binomial storage time/temperature, must be kept under control. This overview will present the importance of reducing these pro-oxidizing effects, as well as the main changes which may occur during the storage of virgin olive oil at the expense of the minor constituents that are more relevant for the olfactive and gustative characteristics and its impact on the aroma and taste of the oil, particularly the phenolic and volatile compounds.