Anais do Simpósio Latino Americano de Ciências de Alimentos
Anais do 14 SLACA - Simpósio Latino Americano de Ciência de Alimentos

The olive trees (Olea europaea L.) have been cultivated in Brazil. Their leaves are rich in phenolic compounds, and their profile and quantity change according to cultivar and the biological cycle. Thus, this work aims to correlate oleuropein content (main phenolic compound of olive leaves) and the antioxidant activity of the olive leaves extracts at different cultivars (Arbosana, Koroneiki, and Arbequina) and development stages. The leaves were harvested in the last fortnight of each season, dried at 35°C in an oven and ground. The leaves extracts were obtained putting 0.2 g of leaves powder, 0.36% disodium EDTA (ultrapure water, w/w), and 10 mL of solvent (ethanol/water 50%) in a tube, which was shaken for 1 hour in an ultrasonic bath and centrifuged (11 rpm, 9 min, 4° C). The supernatant was collected, and the residue was submitted to 4 more extractions. Oleuropein was identified and quantified by UPLC-DAD and antiradical scavenging activity DPPH was determined by IC50 method. The Arbosana cultivar presented highest amounts of oleuropein in summer (16.47 mg/g dried extract (DE)), Koroneiki in spring (12.22 mg/g DE) and Arbequina in spring (13.82 mg/g DE) with the summer being equal statistically (11.64 mg/g DE). Arbosana had the best result for DPPH in spring, contradicting the results of oleuropein probably due to other phenolic compounds more reactive to DPPH present in this season. Already for Koroneiki and Arbequina, the best results were in spring (182,23 mg/g DE) and summer (164,84 mg/g DE), showing their high antioxidant activity came from oleuropein. The different harvest periods (and consequently different olive leaves development stages) had a strong influence on oleuropein content and the antioxidant activity of extracts.