Lipoxygenase pathways metabolites associated to antioxidant properties of tunisian monovarietal virgin olive oils

Olive oil, rich in bioactive compounds and antioxidants, is renowned for its health benefits. The lipoxygenase pathway contributes to the formation of antioxidant metabolites in virgin olive oils. This study examined the impact of location on volatile compounds, fatty acids, and antioxidants in Chétoui monovarietal olive oil from thirteen Tunisian regions. Analysis detected 37 volatile compounds, displaying significant compositional differences across regions. The predominant volatile compound, (E)-2-hexenal, exhibited noteworthy variations, reaching peak levels in Dogga II and Thibar at 24.9% and 23.1% respectively. Fatty acid composition revealed varying percentages of linoleic acid (C18:2) and linolenic acid (C18:3). Amdoun exhibited the highest C18:2 content at 17.5%. Similarly, C18:3 ranged from 0.7% in Slouguia to 0.8% in Teboursouk. Comparative analysis of oxidative stability and antioxidant activity indicated significant differences among regions. Testour II (52 h) and Medjez El-Bab II (44 h) demonstrated higher stability. Regarding antioxidant activity, Teboursouk displayed the highest value at 96.46% and 83.13% for DPPH and ABTS assays, while Thibar scored the lowest at 93.64% and 77.52% for DPPH and ABTS assays. The correlation coefficients reveal that oxidative stability has a negative correlation with DPPH activity (-0.4106) and ABTS activity (-0.491). In contrast, there is a strong positive correlation between oxidative stability and 1-Hexanol (0.584). Furthermore, the fatty acids C18:2 (-0.599) and C18:3 (-0.273) demonstrates negative correlations with oxidative stability. They provide novel insights into the relationship between the lipoxygenase pathway and olive oil’s antioxidant properties, contributing to the production of high-quality olive oils with enhanced antioxidant attributes.