Abstract
Minor polar components (CPM) are natural organic compounds mostly present (1-2%) as a micro-emulsion in virgin olive oil (VOO). Among CPM, phenolic compounds have both technological, sensory and health implications. Analitically, CPM can be extracted from VOO by using hydroalcoholic solutions. Mass spectrometry was coupled with capillary gas chromatography (GC) and high performance liquid chromatography (HPLC) and the mass fragmentations of the main CPM were discussed. The GC analysis with a non polar stationary phase (5% phenyl) allowed the identification of low molecular weight phenolics compounds (tyrosol, hydroxytyrosol and their acetate esters, vanillin and its derivatives), reducing sugars and free fatty acids (150-250 °C elution temperature). Secoiridoids (identified by means of their diagnostic fragments, respectively m/z 192 for ligstroside aglicone and m/z 280 for oleuropein aglicone), monoacylglycerols and other derivatives of tyrosol and hydroxytyrosol were eluted between 150 and 250 °C. Llgnans (pinoresinol and acetoxypinoresinol) and triterpenic acids (oleanolic and masunic acid) were eluted at temperatures higherthan 300 °C. In reversed phase HPLC, small weight phenolics were also eluted before secoiridoids, acetoxypinoresinol, luteolin and an unknown hydroxytyrosylderivative. Since there were no diagnostic fragments identifying the two groups of secoiriooids, each fragmentation path was discussed.