https://doi.org/10.15255/KUI.2025.010
Published: Kem. Ind. 74 (11-12) (2025) 487–496
Paper reference number: KUI-10/2025
Paper type: Original scientific paper
Download paper:  PDF

Phenolic Profile and Biological Potential of Olive Leaves from Organically Cultivated Cultivars

D. Čulum, A. Nuić, Ž. Šimović and R. Vučina

Abstract

Olive cultivation, besides yielding fruit, generates significant amounts of by-products such as olive leaves, which often remain unused. Although the presence of valuable phenolic compounds such as oleuropein and flavonoids, with proven benefits for human health, is well known, this by-product remains underutilised. In this study, the leaves of four olive cultivars, Levantinka, Leccino, Istarska bjelica, and Oblica, grown under organic agricultural conditions, were collected in June 2024, and their chemical composition and biological activity were analysed. Total phenolic content ranged from 1392.15 to 2476.87 mg GAE/100 g dry material, while the content of total flavonoids varied from 181.60 to 265.30 mg QUE/100 g dry material. Five phenolic compounds (oleuropein, hydroxytyrosol, luteolin, luteolin-7-O-glucoside, and quercetin) were identified. Oleuropein was the most abundant compound, with its content varying from 673.32 to 2362.04 mg/100 g dry material. The extract of the Leccino showed the best ability to scavenge free radicals, while the extract from Oblica exhibited the strongest metal-chelating ability. Enzyme inhibitory activity against acetylcholinesterase (AChE) ranged from 26.58 to 33.13 %, while the results for inhibition of butyrylcholinesterase (BChE) varied from 11.11 to 32.57 %. The photoprotective activity of the extract solutions was determined spectrophotometrically using the Mansur mathematical equation. The obtained SPF values ranged from 15.57 to 16.87, corresponding to a blockage of over 93 % of UV radiation. The results of this research provide valuable data supporting the use of olive leaves as a potentially low-cost, renewable, and abundant source of bioactive compounds.

This work is licensed under a Creative Commons Attribution 4.0 International License

Keywords

biological activity, oleuropein, olive leaves, phenolic compounds, photoprotective activity, antioxidant activity, enzyme inhibitory activity