HPLC PROFILE ANDEVOLUTION DURING STORAGE OFTRIGLYCERIDES AND DIGLYCERIDES INVIRGIN OLIVE OILS

High-performance liquid chromatography has been used for determining thetriglyceridice and diglyceridice composition of olive oils from main, minor and neglectedSicilians cultivars.The HPLC analysis has allowed the identification and the quantification of16 triglycerides. Among these, OOO, POO+SOL, OOL and POL, have showna content higher than 84% of the total area of peaks in the chromatographicprofile. Dioleine (OO) and oleopalmitine (OP) resulted the most representativediglycerides.Analyses have been made in January 2007 and repeated after six months,submitting samples to a simulation of shelf life, to verify as the storage conditionsmay influence the hydrolitic processes of triglycerides, producing variations inthe diglyceridic profile. The importance of study about the diglycerides is in factto impute the correlation between the content in mono and diglycerides and theoxidative stability of oils.The experimentation has allowed to verify meaningful decrements in oleopalmitine(OP) content, while opposite course have shown the dipalmitine (PP), and thestearilpalmitine (SP).Principal component analysis (PCA), were applied to data of content of varioustriglycerides and diglycerides, to explore their capacity to discriminate varieties ofolive oil, belonging to a Sicilian origin denomination.That statistic analysis permitted moreover to differentiate significantly samplesin the two different storage periods.