The influence of lighting on shelf-life of extra virgin olive oil packaged in coloured PET bottles

Different storage solutions aimed to assess the shelf-life of extra virgin olive oil (EVOO) packed in PET bottles are presented. Coloured PET bottles (clear, green, orange, white and blue) were stored under different artificial lighting conditions in order to simulate the market conditions (one fluorescent cool white lamp), to perform an accelerated test (4 fluorescent cool white lamps), and in the darkness as control. Acidity, peroxide value, spectroscopic indices (K232, K270, K316), chlorophyll fractions, β-carotene and total polyphenols were determined. Oil colour was measured according to CIE L*-a*-b* scale. Results suggested that the quality indexes most affected by lighting and useful to investigate the bottle colour influence were total peroxide value, polyphenols, chlorophyll, and carotenoid contents. Between the PET bottles stored under one fluorescent lamp, the best performances were obtained using the blue and white colour, while under accelerated conditions, the differences in the protection efficacy offered by the differently coloured bottles was reduced.