Chemical and Sensory Characterization of Nine Spanish Monovarietal Olive Oils: An Emphasis on Wax Esters

Abstract

Olive oil is an essential part of the so-called “Mediterranean diet”, purportedly one of the healthiest gastronomic traditions in the world. The wax content in olive oil is regulated under European Union directives, and it is used as a purity parameter for extra-virgin and virgin olive oils. The wax profile may also help the characterization of monovarietal olive oils. In this study, monovarietal oils were extracted from the fruits of nine native Spanish olive varieties (‘Arbequina’, ‘Argudell’, ‘Empeltre’, ‘Farga’, ‘Manzanilla’, ‘Marfil’, ‘Morrut’, ‘Picual’ and ‘Sevillenca’), and their chemical and sensory attributes were determined. Total wax content in oil was cultivar-dependent and ranged widely between 26 (‘Manzanilla’) and 144 mg kg−1 (‘Arbequina’), while it was negligible in ‘Picual’ oil. The wax ester fraction was comprised largely of phytol-containing diterpene esters, with phytyl vaccinate and phytyl arachidate being the most common components of this non-polar fraction in all nine olive oils assessed. A direct relationship between phytyl esters and the sensory perception of “ripe fruit” notes was also observed.