Zeytin Yapraklarının Antioksidan Aktivite ve Fenolik Bileşenleri Üzerine Sulama İşleminin ve Toplama Periyodunun Etkisi

Abstract

Olive leaves have drawn attention because of their contents of bioactive compounds that exhibit antioxidant activity. The aim of this study was to investigate the impact of irrigation on the phenolic compounds and antioxidant activity of olive leaves belonged to different varieties collected between September and December in irrigated and rainfed orchards. Principal components analysis (PCA) was used to explain the effect of variables. The highest total phenolic content was determined in irrigated Ayvalık leaves (1945 mg/100g). Results showed that olive leaves contained significant amounts of flavonoids, ranging from 6379 to 159046 mg/100g. However, differences in antioxidant activity were generally between 1 and 2% regarding irrigation, collection time, and variety. Luteolin-7-glucoside (273-1461 mg/100g) was the main phenolic compound of olive leaves, followed by verbascoside (399-1002 mg/100g). The influence of irrigation showed differences in the amounts of phenolic compounds among the cultivars.