Chemical characterization and antioxidant properties of products and by‐products from Olea europaea L.

The products and by-products of Olea europaea L.: olive fruits (primary agricultural product), oils (primary agro-industrial product), pomaces (agro-industrial processing by-product), and leaves (agricultural practices by-product), are promising sources of bioactive compounds. In the present study, qualitative and quantitative analyses of selected bioactive components in olive fruits, oils, and pomaces were performed. Total polyphenol content and antioxidant activity were analyzed in all samples (humid pomaces 2015: TPP, 26.0 ± 1.5–43.7 ± 3.0 g(GAEq)/kg DW; TEAC/ABTS, 189.5 ± 3.7–388.1 ± 12.0 mmol(Trx)kg DW). Radical (DPPH) quenching potential was analyzed via photometric and EPR methods, obtaining Vis/EPR signal ratio by 1.05 ± 0.45 and 1.66 ± 0.39 for fruits and pomaces, respectively. Through HPLC-UV and HPLC-MS/MS techniques, oleuropein and hydroxytyrosol, as well as selected hydroxycinnamic acids and flavonoids, were identified and quantified in olive fruits and pomaces. The main components were rutin, luteolin, and chlorogenic acid. Cytotoxic assay on fibroblast cells revealed toxic effects for selected extracts at highest tested concentrations (5%)

CHARACTERIZATION OF ANTIOXIDANT PROPERTIES OF VEGETABLE PRODUCTS AND RESIDUES BY DIFFERENT PRODUCTION TECHNOLOGIES

The thesis reported on the chemical characterization of antioxidant properties of several vegetables (products and relevant by-products), with particular attention to olive tree derivatives. The results showed that the by-products of Olea europaea L. (leaves) and olive oil production (pomace), as well as not edible part of plants like tomato (leaves) are promising sources of bioactive compounds, particularly polyphenols and glycoalkaloids, respectively for olive leaves and pomace, and tomato leaves. Considering the health-giving effects of polyphenolic antioxidants and the importance of olive oil production, as well as vegetables production, in all Mediterranean countries, it is urgent to study all biologically active molecules for nutraceutical uses, for the production of functional foods and for other purposes such as cosmetics. Promotion of the primary and secondary components of olive production is a model to use in other areas of agriculture (e.g. viticulture, horticulture, cereal crops) to maximize the use of nutritional and nutraceutical resources and to make agriculture economically sustainable