Influence of Exposure to Sunlight on the Oxidative Deterioration of Extra Virgin Olive Oil during Storage in Glass Bottles

Abstract

The protective effect of glass bottles with different levels of transparency (clear or amber glass) on the quality of extra virgin olive oil was evaluated after exposure to sunlight or storage in clear glass bottles covered with aluminum foil for 5 weeks. Oils stored in clear glass bottles had significantly higher values of all quality parameters (free fatty acids, peroxide value, and K270), and lower pigment (chlorophylls and carotenoids) and phenolic contents than the same oils stored in covered or amber glass bottles. Oils stored in covered glass bottles showed no deterioration, whereas oils stored in amber glass bottles contained primary oxidation products. Sunlight exposure produced acrolein in the oils stored in clear glass bottles, but not to the same extent in oils stored in covered and amber glass bottles. These results show that low transparency packaging provides protection against sunlight-induced oxidative deterioration of extra virgin olive oil during storage.