Comparison of biochemical and antioxidant activities of ultrasonic-assisted extraction with different solvents in olive leaf

Authors : Damla ÖNDER, Ümit ERDOĞAN, Sercan ÖNDER

Pages : 31-40

Doi:10.38042/biotechstudies.1274148

View : 180 | Download : 136

Publication Date : 2023-06-30

Article Type : Research Paper

Abstract :Olive leaves are considered to have great potential as natural sources of antioxidants and phenolic compounds. In this study, dried olive leaves were extracted using four different solvents insert ignore into journalissuearticles values(water, methanol, ethanol, and 80:20insert ignore into journalissuearticles values(v/v); methanol-water); with ultrasonic-assisted extraction. The biochemical insert ignore into journalissuearticles values(total phenolics and flavonoids, total protein, free amino acids, total soluble, and reducing sugars); and antioxidant activities insert ignore into journalissuearticles values(CUPRAC, DPPH, FRAP, and FIC); of these extracts were evaluated. Total phenolics content was significantly affected by the different solvents and the highest total phenolics content was obtained in methanol-water insert ignore into journalissuearticles values(234 mg g-1); extraction. The highest total flavonoid insert ignore into journalissuearticles values(47 mg g-1); and total protein insert ignore into journalissuearticles values(5.1 mg g-1); content were obtained in methanol extraction. Yield of the free amino acids was lowest in ethanol insert ignore into journalissuearticles values(1.5 mg g-1);, while it was highest in water insert ignore into journalissuearticles values(2.3 mg g-1); and methanol-water insert ignore into journalissuearticles values(2.2 mg g-1); extractions. The highest total soluble sugars were obtained from methanol-water insert ignore into journalissuearticles values(70.4 mg g-1); and ethanol insert ignore into journalissuearticles values(65.4 mg g-1); extractions, while the highest total reducing sugar contents were obtained from methanol insert ignore into journalissuearticles values(112.2 mg g-1); and methanol-water insert ignore into journalissuearticles values(111.6 mg g-1);. While methanol-water extraction showed the highest antioxidant capacity with 0.63 mmol TR g-1 CUPRAC value, it also showed the strongest radical scavenging activity with 1.09 mmol TR g-1 DPPH radicals value and 0.065 mmol TR g-1 FRAP potential value. FIC capacity was higher in water than in other solvent extraction methods. Methanol and methanol-water solvents were the most effective solvents for measuring phenolic and antioxidant activities in olive leaves.
Keywords : Cupric reducing antioxidant capacity, DPPH, Ferrous ion chelating, Ferric reducing antioxidant power, Phenolics, Sugars