Fenolne spojine in antioksidativni potencial v listih in lesnih poganjkih oljke

Polak, Ivana (author), Vidrih, Rajko (mentor), Abramovič, Helena (co-mentor)

V okviru magistrske naloge smo izvedli raziskavo na listih in lesnih poganjkih oljk petih različnih sort: Maurino, Leccino, Belica, Pendolino ter Leccio del Corno. Bioaktivne spojine smo ekstrahirali v ultrazvočni kopeli pri 60 °C, 30 min z uporabo metanola kot ekstrakcijskega topila. Vzorcem smo določali vsebnost skupnih fenolnih spojin (TPC) spektrofotometrično s pomočjo Folin-Ciocalteujeve metode, vsebnost skupnih flavonodiov (TFC) z uporabo aluminijevega (III) klorida, antioksidativni potencial (AOP) s pomočjo DPPH⠙ radikala in antioksidativno učinkovitost v emulziji linolne kisline v vodi z metodo beljenja β-karotena. Določili smo tudi posamezne fenolne spojine z uporabo tekočinske kromatografije visoke ločljivosti (HPLC). Glavne fenolne spojine v listih so bili olevropein in luteolin-7-glukozid, v poganjkih pa olevropein in neidentificirana spojina. Rezultati so pokazali da vsebujejo listi več fenolnih spojin v primerjavi s poganjki. Sorta Leccio del Corno izstopa kot sorta, ki je najbolj bogata s fenolnimi spojinami v listih, pri poganjkih pa sorta Pendolino. Med vrednostmi TPC, TFC in AOP pri vzorcih listov je bila pozitivna povezava zelo močna.

• Language: Slovenian
• Keywords: oljka, Olea europaea, listi oljke, lesni poganjki, fenolne spojine, antioksidativni potencial
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [I. Polak]
• Year: 2021
• PID: 20.500.12556/RUL-127212
• UDC: 634.63:547.56:66.094.3.097.8
• COBISS.SI-ID: 64705795
• Publication date in RUL: 26.05.2021

Secondary language

• Language: English
• Title: Phenolic compounds and antioxidant potential of olive tree leaves and shoots

Abstract

In this master's thesis, a study on olive leaves and shoots of five different varieties, Maurino, Leccino, Belica, Pendolino, and Leccio del Corno was conducted. The bioactive compounds were extracted in an ultrasonic bath at 60 °C for 30 min using methanol as the extraction solvent. The samples were analyzed on the content of total phenolic compounds (TPC) spectrophotometrically using the Folin-Ciocalteu method, the content of total flavonoides (TFC) using aluminum (III) chloride, antioxidant potential (AOP) by DPPH· radical. Moreover the antioxidant efficiency in emulsion of linoleic acid in water by the β-carotene bleaching method was carried out. Individual phenolic compounds were determined using high-performance liquid chromatography (HPLC). Major phenolic compounds in leaves were oleruopein and luteolin-7-glucoside while in shoots oleuropein and nonidentified compound. The results showed that leaf contains more bioactive compounds as compared to shoots. The leaves of the Leccio del Corno variety and the shoots of the Pendolino variety contained more phenolic compounds as compared to other varieties. A strong positive correlation was found between TPC, TFC, and AOP values in leaf samples.

• Keywords: olive tree, Olea europaea, olive leaves, shoots, phenolic compounds, antioxidant potential