Application of Dispersive Liquid-Liquid Aerosol Phase Extraction to the Analysis of Total and Individual Phenolic Compounds in Fried Extra Virgin Olive Oils

Seventeen extra virgin olive oil samples from ValencianCommunity(Spain) were submitted to a domestic-frying process (180 & DEG;C)during different degradation times (5, 10, 30, 60, 120 min). A dispersiveliquid-liquid aerosol phase extraction by using a methanol/water(50:50) extracting solution was used to isolate the polyphenol fraction.Total phenolic content (TPC) was determined, whereas the determinationof seven individual target polyphenolic compounds (hydroxytyrosol,tyrosol, oleuropein, vanillic acid, p-coumaric acid,ferulic acid, and vanillin) was carried out by using ultrahigh-performanceliquid chromatography coupled to a tandem mass spectrometer. Statisticallysignificant differences in the TPC values were found for Blanquetaand Manzanilla samples from different harvesting years. The domestic-fryingprocess impacted the TPC and the individual phenolic compounds content.Thermal treatment for 2 h gave rise to a 94% decrease in the TPC.A first-order kinetic model was suitable to accurately describe thedegradation of the individual phenolic compounds.