Natural antioxidants of virgin olive oil obtained by two and tri-phase centrifugal decanters

The new dual-phase decanter does not require any addition of water to process olive paste and produces very limitated quantities of vegetable water. Consequently, the elimination of big waste water problem makes particularly interesting this technological innovation. Therefore, in order to evaluate, in comparison with the traditional decanter, its effectiveness in relation to the qualiquantitative composition of natural antioxidants, tocopherols and phenolic compounds were determined on samples of virgin olive oils obtained by centrifugal decanters at two and three phases. Particularly, phenolic substances were analysed by colorimetric, HPLC and HRGC methods. The results obtained proved that oils extracted by dual-phase decanter had higher concentrations of both tocopherols and phenols, especially o-diphenols, and showed higher stability to oxidation. The resistence to oxidation appeared better correlated with the content of simple and linked o-diphenols and of aglycon of decarbomethoxy ligstroside.