Enrichment of refined sunflower oil with phenolic extracts from argan (Argania spinosa L. (Skeels)) co-products using ultrasound-assisted extraction

Vegetable oils, rich in unsaturated fatty acids, are highly susceptible to oxidation, requiring antioxidants to ensure stability. In this study, phenolic-rich extracts from argan (Argania spinosa L. (Skeels)) co-products were obtained by ultrasound-assisted extraction (UAE) and incorporated into refined sunflower oil (100 and 200 ppm). The oxidative stability of enriched oils was compared to a non-enriched control and vitamin E-supplemented oils. Chemical characterization confirmed that argan co-products extracts contained high levels of phenolics and flavonoids with strong antioxidant activity. Quality indices (peroxide value, acidity, p-anisidine, K₂₃₂, K₂₇₀, and fatty acid profile) showed no significant changes between enriched and control oils, indicating that the ultrasound enrichment process did not compromise oil quality. Rancimat analysis demonstrated a marked improvement in oxidative stability, particularly for pulp extracts at 200 ppm, which yielded the longest induction period compared to both controls. These findings highlight the potential of argan co-products as sustainable sources of natural antioxidants, offering an efficient and safe alternative to synthetic stabilizers in edible oils.