Folhas de Oliveira (Olea europaea L): composição em bioativos, atividades antioxidante e biológica

Abstract

Oliveira (Olea europaea L.) belongs to the botanical family Oleaceae, being one of the oldest fruit grown by man. The olive leaves are usually discarded during the olive production process, and therefore, they are still little explored. However, it is attributed to them beneficial health effects, mainly due to the presence of compounds with bioactive activities. In order to valorize its nutritional and bioactive characteristics, a complete characterization is necessary. This study was divided in two experiments, and had as objective the physicochemical evaluation and bioactive compounds content, as well as the biological evaluation of the olive leaves. It was determined the proximal composition, pH, titratable acidity, minerals, bioactive compounds, individual phenolic compounds, antioxidant activity, antimicrobial activity, glycemia evaluation, lipid profile and lipid peroxidation of aqueous extracts of olive leaves in rats fed with hyperlipidic diets. Olive leaves are high in fiber and protein, with potassium and calcium as the major minerals. A high content of bioactive compounds was found, being the flavonoids, carotenoids, rutin and campferol the major ones. Olive leaves showed antioxidant activity and potentiall against bacterial E. coli and S. aureus. Differences were found in the leaves from diferent cultivars, in the physico-chemical and proximal characterization, as well as in the bioactive compounds content, antioxidant and antimicrobial activity. The consumption of olive leaf extract by rats promoted changes in the lipid profile and a beneficial effect in relation to TBARS levels. Due to their composition, antioxidant and biological properties, olive leaves may prove to be an option as a food supplement.