ANALYTICAL DEFINITION OF THE QUALITY OF EXTRA-VIRGIN OLIVE OIL STORED IN POLYETHYLENE TEREPHTHALATE BOTTLES

To assess the role of the container material on the quality of olive oil, 16 samples of selected extra-virgin olive oils (obtained in dark-green glass bottles as soon as they were produced) were stored in colorless polyethylene terephthalate (PET) bottles and in dark-green glass bottles for 2 months. For the very first time, room temperature and daylight storage were used to mimic the actual household storage conditions. Results clearly indicate that peroxide value increases rapidly above the threshold value; there was also an increase of free fatty acids and acidity and strong sensory quality loss upon storage in PET bottles. Influences of the technological operation adopted during oil extraction are discussed.