Monitoring the shelf life of extra virgin olive oil using Fluorescence spectroscopy

Abstract

To maintain the quality of extra virgin olive oil (EVOO), one important factor is to resist its oxidation during processing and storage. It is challenging task to prevent oxidation in EVOOs since various physical and chemical factors must be under control. In the present study extra virgin olive oil was stored under normal storage conditions for three months and monitored via quality parameters. A non-destructive fluorescence spectroscopy was performed to monitor the oxidation changes in EVOO from different olive growing regions of Pakistan and Al-Jouf region of the Kingdom of Saudi Arabia (KSA). Additionally, the impacts of geographic, climatic, and environmental factors on the oxidation of EVOOs were investigated. Two major changes in the fluorescence emission spectra of EVOO samples were mainly observed: a decrease in fluorescence emission intensities in the range between 500 to 600 nm, 650 to 690 nm, as well as a rise in the fluorescence emission intensities in the 365–500 nm region. These two changes were related to a degradation of beta carotene, chlorophyll content and formation of oxidation products. EVOO samples collected from Al-Jouf region, KSA showed low rate of oxidation which might be due to environmental and geographical effect, proper irrigation system, harvesting, processing and storage conditions. In a fast and non-destructive manner, The fluorescence spectroscopy successfully monitored the oxidation changes and deterioration of antioxidants in a rapid and non-destructive manner in the EVOOs.