Determination of Total Antioxidant Capacity of Corylus avellana L. (Hazel) Leaves Collected from the Elazığ/Keban Region

Abstract

The objective of this study was to introduce the overall bioactive content (total antioxidant capacity, total flavonoid content and total phenolic content) of fresh and healthy leaves of Corylus avellana L. (Hazel) obtained from the Elazığ/Keban region in September. The hazelnut leaves were dried in an oven at 55℃ for 48 hours. Then, a thermal pretreatment was performed by using two different methods which are microwave and infrared techniques. The C. avellana L. samples were subjected to extraction treatment. The extraction was separately carried out using ethanol and water. The total phenolic content, the total flavonoids, and the total antioxidant capacity were determined using the Folin-Ciocalteu method (Gallic Acid Equivalent, GAE), the AlCl3 method (quercetin equivalent, QE), and ABTS method (Trolox Equivalent Antioxidant Capacity, TEAC), respectively. As a result, the total phenolic content value of the hazelnut studied was calculated as 37.95±0.51 mg/g GAE. The flavonoid content was measured as 68.10±0.585 mg/g QE. Finally, the total antioxidant capacity was 10.92±0.02 mmol/g TEAC. In light of all these findings, it might be said that C. avellana L. leaves studied have considerable quantities of bioactive compounds.