Efeito da luz na degradação de azeite em diferentes embalagens

Abstract

The shelf life of olive oil is limited by photo-oxidation, auto-oxidation and lipolysis. During the process of olive oil degradation occurs a series of chemical reactions involving unsaturated fatty acids, light, moisture and oxygen. In this way the stowage in suitable packaging is able to keep stable oxidation and ensure a proper life cycle, taking into account the oil impermeability, gas impermeability and protection against light. Thus the aim of this experiment was to verify the degradation of olive oil under different conditions of light exposure in different packages (PET and glass). Initially the samples were stored: half of them in a cardboard box hidden from the light and half were exposed to ambient and/or artificial light for 3 months. Over the months were performed analysis of the acidity, peroxide index, specific extinction at 232 and 270 nm, chlorophyll, carotenoids, total phenols and transmittance. During the analyzed period small variations occurred in the values of acidity, peroxide index and specific extinction, but did not exceed the values determined by the resolutions. In the analyzes of chlorophyll and carotenoid pigments, occurred a decrease in values during the months of storage. In the colorimetric analysis, it was possible to affirm that in the dark the PET has a better oxygen barrier, since the glass has better barrier to oxygen in ambient light. From the results obtained, we can affirm that in the short term green PET packaging is the most effective to guarantee the quality of olive oil.