Application of accelerated shelf-life test (ASLT) procedure for the estimation of the shelf-life of extra virgin olive oils: A validation study

The shelf-life (SL) estimation of extra virgin olive oil is a timely concern for food producers not only to comply with EU regulations throughout the whole product life cycle, but also to maintain consumer trust in the pro-ducers. The application of accelerated shelf-life testing (ASLT) procedures could allow to speed up the process. In this study, three fresh made extra virgin olive oils having increased total polyphenol content (156, 273 and 507 mg/kg) were stored at increasing temperatures (25, 40, 50 and 60 degrees C) in the dark in glass containers under reduced oxygen content to simulate market storage. The changes of K270 and % of pyropheophytin a (PPP) were found to be the best indicators to monitor product behaviour during storage. The rate constants of the changes of K270 and %PPP over time showed a temperature dependence that can be described with the Arrhenius model with activation energies (Ea) in the range of 49-65 kJ/mol and 115-122 kJ/mol for K270 and %PPP, respectively. These values confirmed the significant higher susceptibility of the parameter %PPP to temperature changes during storage, as also demonstrated by the estimated shelf-life values and relevant confidence intervals. Interestingly, the initial quality characteristics of the oils and especially the polyphenols content did not affect the temperature dependence of the rate constants of these indexes. It was concluded that %PPP could be used as a "rapid alert" indicator of product performances on the market and K270 as indicator to compute the compulsory value of "best before" date.