Sea Fennel-Flavored Vegetable Oils: Chemistry and Stability During Storage

Traditionally, various herbs and spices are used to enhance the flavor and aroma of vegetable oils, but also to improve their nutritional value and stability. The aim of this work was to investigate the effects of sea fennel, an aromatic edible Mediterranean halophyte plant, leaf infusion, on the chemical composition of four unrefined edible vegetable oils (olive, sunflower, sesame and flaxseed oil). During the 90-day storage period, the quality parameters of the oils (peroxide value, free fatty acids and fatty acid profile), as well as their volatiles, were monitored. Free fatty acids and peroxide values increased in all samples, with the greatest increase in the olive oil (11% and 45%, respectively), while the effect on the fatty acid profile was negligible. Gas chromatography-mass spectrometry analysis showed the effect of oil aromatization by sea fennel components and confirmed the differences between oil samples. The results suggest that the addition of sea fennel to vegetable oils leads to changes in their chemical composition, and the parameters tested varied between the oils used.