Direct enrichment of olive oil in oleuropein by ultrasound-assisted maceration at laboratory and pilot plant scale

Sabiha Achat (1) , Valérie Tomao (1) , Khodir Madani (2) , Mohamed Chibane (2) , Mohamed Elmaataoui (1) , Olivier Dangles (1) , Farid Chemat (1)

1 SQPOV - Sécurité et Qualité des Produits d'Origine Végétale
2 UB - Université Abderrahmane Mira [Université de Béjaïa] = University Abderrahmane Mira [University of Béjaïa]

The possibility to improve the nutritional value of olive oil by enriching it in phenolic compounds from olive leaves (e.g., oleuropein) by ultrasonic maceration was studied. The experimental design used led to the following optimal extraction conditions: ultrasonic power of 60 W, temperature of 16 °C and sonica-tion duration of 45 min. The high total phenolic content (414.3 ± 3.2 mg of oleuropein equivalent/kg of oil), oleuropein (111.0 ± 2.2 mg/kg of oil) and a-tocopherol (55.0 ± 2.1 g/kg of oil) concentrations obtained by optimized ultrasound-assisted extraction (UAE) proved the efficiency of this process when compared with the conventional solid–liquid extraction. Histochemical analyses showed that this efficiency is due to specific alteration of the phenol-containing leaf structures. Furthermore, the radical -scavenging activity of the processed oil (DPPH test) and its stability toward lipid autoxidation (heating test) confirmed its enrichment in antioxidants. Sensory evaluation of the enriched olive oil showed a slight increase in bitterness but an overall acceptability. Finally, the enriched olive oil was characterized by clear green color (L ⁄ , a ⁄ , b ⁄ parameters).

Domaines: Sciences du Vivant [q-bio]; Biologie végétale

Sabiha Achat, Valérie Tomao, Khodir Madani, Mohamed Chibane, Mohamed Elmaataoui, et al.. Direct enrichment of olive oil in oleuropein by ultrasound-assisted maceration at laboratory and pilot plant scale. Ultrasonics Sonochemistry, 2012, ⟨10.1016/j.ultsonch.2011.12.006⟩. ⟨hal-01332299⟩