Metabolic patterns in the lipoxygenase pathway associated to fruitiness attributes of extra virgin olive oil

Abstract

Fruitiness is one of the most appreciated organoleptic features of extra virgin olive oils (EVOOs), which are categorized as a function of the fruitiness intensity and typology. In this research, we determined the main C5 and C6 volatiles formed through the lipoxygenase pathway (LOX) in 200 EVOOs produced in two agronomic seasons. Multivariate analysis was applied to find discrimination patterns in the concentrations of volatiles in EVOOs, which were tasted and classified in terms of fruitiness by the Panel Test. Multivariate ROC analysis of metabolic ratios governing the formation of C5 and C6 volatiles allowed identifying the main enzymatic steps contributing to explain chemical differences in the volatile composition of EVOOs. Fruitiness intensity was specially explained by the conversion of 3-hexenal to 2-hexenol and 3-hexenol, whereas the type of fruitiness was conditioned by the three branches of the LOX pathway that lead to the formation of C5 and C6 volatiles.