Virgin olive oil stability study by mesh cell-FTIR spectroscopy.

Mesh cell is a rapid tool designed to monitor chemical changes that occurs as a consequence of oxidation at moderate conditions. In this study this accessory has been proposed for assessing virgin olive oil (VOO) stability by Fourier transform infrared (FTIR) spectroscopy. Monocultivar VOOs have been stored in mesh cells under different temperatures (at 23, 35, 65°C) simulating the real conditions during storage and transport (<60°C). In addition to temperature, the samples have been also stored in mesh cells at different light intensities (400, 1000, 7000lx) to evaluate the resistance of the samples to photooxidation. The oil stability of the samples determined by using this accessory has been compared with the oil stability determined with the common methods used for this purpose (e.g. Rancimat). Despite the moderate conditions applied, mesh cell-FTIR spectra have revealed the formation of hydroperoxides and the subsequent formation of alcohols and aldehydes. Unlike other methods that require high temperature to accelerate the oxidation rate, mesh cell-FTIR has allowed differentiate the oil stability of the samples from a multi-factor perspective that includes several properties (temperature and light) and chemical species (primary and secondary oxidation products). The information obtained with this method can be relevant for optimizing handling (e.g. packaging and storage temperature) of VOO samples during their shelf life.