摘要：Background: Recent studies suggest that olive leaves are a significant source of bioactive phenolic compounds comparable to olive oil and fruits. Identifying pretreatment before extraction such as solar dried, oven dried and blanched is thus essential to increase the level of such bioactive components in olive leaves, which is considered an agricultural waste. One of these treatments was blanching on 90-95°C for 20 sec. Objective: So, the aim of the present study was undertaken in order to investigate the impact of appropriate treatment before drying and extraction on the total phenolic compounds quantity and antioxidant activity in olive leaves. Methodology: Olive leaves samples were divided into four parts, Fresh Leaves (FL), Solar Dried Leaves (SDL) and Oven Dried Leaves (ODL) and Blanched Dried Leaves (BDL) on (90-95°C) (1:4 w/v) for 20 sec. Total phenolic content, flavonoids and antioxidant activity of different treatments of olive leaves were estimated. Results: The blanching of olive leaves for 20 sec increased up to 593.00 μg GAE g1 (61.70%). A linear relationship was observed between the potential antioxidant activity , total phenolic and flavonoid levels of the olive leaves extract. These results emphasized that olive leaves were contained significant amounts of phenolic content and flavonoids which crucial for their antioxidant capacity. Ethanol extract of the blanched-dried leaves showed the highest antioxidant activity (IC50 = 149.92 μg mL1) compared to methanol and water extract. Conclusion: In the present study, it can conclude that the bunching of olive leaves may improve the level of phenolic content and flavonoids and consequently antioxidant capacity has been enhanced.
