Evaluation of Italian extra virgin olive oils based on the phenolic compounds composition using multivariate statistical methods

The content of 40 phenolic compounds was determined in 68 samples of extra virgin olive oils (EVOOs) coming from 9 Italian regions using high-performance liquid chromatography coupled to diode array detector and mass spectrometry. Oleuropein isomers (M = 540 g/mol) and derivatives (M = 378 g/mol) together with ligstroside aglycone isomers (M = 362 g/mol) and derivatives (M = 394 g/mol) were the major EVOOs compounds (median of 44-228 mg/kg). On the other hand, verbascoside isomers (M = 624 g/mol) and apigenin (M = 270 g/mol) were the minor compounds (median < 2 mg/kg). Different techniques of multivariate data analysis were applied to find important parameters for discrimination of EVOOs. Principal component analysis and factor analysis distributed the samples into two groups according to the total amount of phenols and quantity of elenolic acid giving information about ripeness of olives. Linear discriminant analysis successfully classified the samples according to their geographical origin into three groups (Northern Italy, Southern Italy, and Sicily).