Effect of storage period and exposure conditions on the quality of Bosana extra-virgin olive oil

Changes in quality parameters, antioxidant compounds, oxidative stability and antioxidant activity during 18 months of storage of a monovarietal extra-virgin olive oil from Bosana cultivar, and exposed to light and dark, were studied. Analysis of data showed that all the parameters underwent significant changes during storage: free acidity, peroxide and ultraviolet (UV) spectrophotometric indexes remained below the limits reported in the EEC Regulations 2568/91 and 1989/03, and these are: <= 0.8% for acidity, <= 20 meq O-2/kg for peroxide and <= 2.50 and <= 0.22 for K232 and K270, respectively. Phenol and alpha-tocopherol content decreased during storage (42.0 and 29.6%, respectively) while chlorophylls and carotenoids underwent a decrease until 8 months of storage (49% and 30%, respectively); after that, the values remained constant. Oxidative stability and antioxidant activity had not changed dramatically during 18 months. Phenols were significantly correlated to the antioxidant activity of the oil, while oxidative stability measured by Rancimat did not show any correlation with carotenoids, chlorophylls, phenols and alpha-tocopherol. Regarding exposure conditions, storage in the dark was better in retaining the quality of the oil, as expected.