Beyond current quality indices: Quantitative volatilomics unrevealed cultivar traits, harvesting practices impact, and aroma blueprint of extra-virgin olive oils

Abstract

Virgin olive oil, derived from Olea europaea L., is a staple in the Mediterranean diet and is classified into quality categories by EU regulations and the International Olive Council. Extra Virgin Olive Oil (EVOO), the highest quality, is valued for its nutritional and sensory attributes, driving consumer willingness to pay a premium. However, this makes EVOO susceptible to fraud, necessitating robust quality control methods. This study combines advanced untargeted fingerprinting and quantitative volatilomics using headspace solid-phase microextraction (HS-SPME) coupled to comprehensive two-dimensional gas chromatography with parallel mass spectrometry and flame ionization detection (GC×GC-MS/FID) on EVOOs from Hojiblanca and Picual cultivars to define robust markers of quality, named cultivar markers and cultivation practice indicators. The comprehensive analysis identified over 190 peak features and 84 compounds, revealing distinct volatile profiles influenced by cultivar, cultivation methods, and ripening stages. Of the 125 diagnostic volatile features (Fisher value > 4) for cultivar discrimination, alkenes, carbonyls, and alcohols predominate. Key compounds, such as (E)-2-octenal, (E)-2-hexenal, and (Z)-3-hexen-1-ol, reflect lipoxygenase pathway activity and maturation stages across cultivars. Quantification confirmed distinct aroma blueprints between cultivars, driven by differences in OAVs of key-odorants. However, minimal differences between odor active markers for organic and conventional cultivation practices, suggest consumers are unlikely to perceive variations in aroma between the two.