Biogenesis of Alcohols Present in the Aroma of Virgin Olive Oil

Abstract

Contrary to most vegetable oils, which are extracted from seeds, virgin olive oil is prepared from the fleshy pulp of a fruit using mild physical procedures, thus resulting in a product highly prized for its nutritional properties and delicate aroma. Six carbon alcohols — hexanol, E-2-hexenol and Z-3-hexenol-, together with their ethyl esters, are important components of the aroma of virgin olive oil (Olias et al., 1980). Investigations carried out in other plants species indicate that such volatile alcohols are formed from polyunsaturated fatty acids through the lipoxygenase pathway, which is triggered upon cutting or crushing the tissue, and involves the participation of lipoxygenase, hydroperoxide lyase and alcohol dehydrogenase (Hatanaka et al., 1973; Vick et al., 1987). The latter catalyzes the reduction of aldehydes produced by the action of hydroperoxide lyase to yield alcohols and is, therefore, responsible for the pattern of volatile alcohols characteristic of each plant species.