Ultrasound-assisted valorization of argan co-products for improving sunflower oil stability under accelerated storage

The argan tree ( Argania spinosa (Skeels) L.), widely known for its oil, also generates co-products such as leaves, pulp, and press cake that remain largely underexploited. This study explored the potential of these co-products as sources of natural antioxidants through ultrasound-assisted ethanolic extraction and evaluated their effectiveness in enhancing the oxidative stability of refined sunflower oil (SFO). Oil samples enriched with two extract concentrations (0.01% and 0.02%) were assessed under accelerated storage conditions (60 °C, 120 d) and by the Rancimat test at elevated temperatures (110 and 120 °C), in comparison with a non-enriched control and vitamin E. Oxidative stability was monitored using conventional quality indices and antioxidant activity assays. The results demonstrated that argan co-product extracts, particularly those derived from leaves and pulp, exhibited strong antioxidant activity and effectively delayed lipid oxidation in SFO. These findings highlight the potential of argan co-products as sustainable sources of natural antioxidants for improving edible oil stability.