The Composition of Volatiles and the Role of Non-Traditional LOX on Target Metabolites in Virgin Olive Oil from Autochthonous Dalmatian Cultivars

• Published in: Molecules (Basel, Switzerland) Vol. 29; no. 8; p. 1696
• Main Authors: Soldo, Barbara, Jukić Špika, Maja, Pasković, Igor, Vuko, Elma, Polić Pasković, Marija, Ljubenkov, Ivica
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-04-2024
• Subjects: 9- and 13-hydroperoxides of octadecenoic acid; Alcohol; Cultivars; Enzymes; Fatty acids; Fruit; Fruit - chemistry; Fruit - metabolism; Fruits; harvest time; Linoleic Acid - metabolism; Lipoxygenase - metabolism; lipoxygenase enzyme; maturity index; Metabolites; Olea - chemistry; Olea - metabolism; Olive oil; Olive Oil - chemistry; Olive Oil - metabolism; Phenols - analysis; Phenols - chemistry; Phenols - metabolism; Proteins; Unsaturated fatty acids; virgin olive oil; volatile compounds; Volatile Organic Compounds - analysis; Volatile Organic Compounds - chemistry; Volatile Organic Compounds - metabolism; Croatia; Spain; Dalmatia; virgin olive oil; total phenolic compounds; 9- and 13-hydroperoxides of octadecenoic acid; harvest time; Levantinka and Lastovka cultivars; Oblica; lipoxygenase enzyme; volatile compounds; maturity index
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules29081696

The lipoxygenase pathway has a significant influence on the composition of the volatile components of virgin olive oil (VOO). In this work, the influence of the maturity index (MI) on the activity of the lipoxygenase enzyme (LOX) in the fruits of the autochthonous Dalmatian olive cultivars Oblica, Levantinka and Lastovka was studied. The analysis of the primary oxidation products of linoleic acid in the studied cultivars showed that LOX synthesises a mixture of 9- and 13-hydroperoxides of octadecenoic acid in a ratio of about 1:2, which makes it a non-traditional plant LOX. By processing the fruits of MI~3, we obtained VOOs with the highest concentration of desirable C6 volatile compounds among the cultivars studied. We confirmed a positive correlation between MI, the enzyme activity LOX and the concentration of hexyl acetate and hexanol in cultivars Oblica and Lastovka, while no positive correlation with hexanol was observed in the cultivar Levantinka. A significant negative correlation was found between total phenolic compounds in VOO and LOX enzyme activity, followed by an increase in the MI of fruits. This article contributes to the selection of the optimal harvest time for the production of VOOs with the desired aromatic properties and to the knowledge of the varietal characteristics of VOOs.