Učinak uvjeta sušenja na fenolni sastav i antioksidacijski kapacitet imele (Viscum album L.)

master's thesis

• Title (english): Effect of drying conditions on phenolic composition and antioxidant capacity of mistletoe (Viscum album L.)
• Author: Hrvoje Hodak
• Mentor: Gordana Rusak (mentor)
• Committee member: Gordana Rusak (predsjednik povjerenstva)
• Committee member: Ivana Buj (član povjerenstva)
• Committee member: Dubravko Pavoković (član povjerenstva)
• Committee member: Ivana Šola (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2019-02-25, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Bijela imela (Viscum album L.), vrsta imele iz porodice Santalaceae, je vazdazelena, drvenasta biljka koja kao epifitski obligatni poluparazit raste na velikom broju drvenastih vrsta. Imela se koristi u tradicionalnoj medicini za liječenje čitavog niza oboljenja. Dio imeline ljekovitosti može se pripisati fenolnim spojevima. Dosadašnja istraživanja su pokazala kako ovisno o biljci domaćinu, vremenu ubiranja i pripremi biljnog materijala sastav i količina fenolnih spojeva, kao i antioksidacijska aktivnost vezana uz njih, jako varirju. Istraživanje je izvršeno na lišću imela koje su rasle na lipi, glogu i javoru. Sa svakog stabla sakupljeno je lišće s peteljkama s po jedne imele. Lišće s peteljkama svake od imela je podijeljeno na dva približno jednaka dijela od kojeg je jedan sušen na sobnoj temperaturi u sjeni dok je drugi liofiliziran. Mjeren je antioksidacijski kapacitet trima spektrofotometrijskim metodama, količina ukupnih fenolnih spojeva metodom Folin-Ciocalteu dok su pojedini fenolni spojevi detektirani metodom tekućinska kromatografija visoke djelotvornosti s obrnutim fazama (RP-HPLC). Utvrđeno je da imela koja je rasla na glogu najbogatija fenolnim tvarima, te kako gledajući u cjelini ima veći antioksidacijski kapacitet u usporedbi s ostalim uzorcima. Liofilizirani uzorci pokazali su veći antioksidacijski kapacitet od svojih na sobnoj temperaturi sušenih parova. Liofilizacija je pokazala pozitivan učinak na očuvanje koncentracije p-kumarinske i sinapilne kiseline.

Abstract (english)

Common mistletoe (Viscum album L.), a species of mistletoe in the family Santalaceae, is a evergreen shrub that grows on a variety of woody plants as a epiphytic hemiparasite. Mistletoe is used in traditional medicine for treatment for number of different ailments. Mistletoe’s positive effects on health can be partially attributed to it’s phenolic content. Recent studies have shown that phenolic content and antioxidant capacity of mistletoe varies depending on plant host, time of the year in which it was collected and preparation of the plant material. Subject of this study were leaves with their petioles from mistletoes that grew on linden, hawthorn and maple from which half of plant material was freeze-dried while other half was dried in shadow at room temperature. Three different spectrophotometric methods were used for measuring the antioxidant capacity, Folin-Ciocalteu method was used for measuring total phenolic content while reversed phase high-performance liquid chromatography (RP-HPLC) method was used for detection of specific phenolic compounds and their concentrations. Results show that mistletoe that grew on hawthorn had highest concentration of total phenolics and generally had highest antioxidant capacity. Freeze-dried samples had higher antioxidant capacity then their coresponding air-dried pairs. Freeze-drying has shown positive effect on preserving of p-coumaric acid and sinapinic acid.

• Keywords: ABTS; DPPH; FRAP; RP-HPLC; p-kumarinska kiselina; sinapilna kiselina
• Keywords (english): ABTS; DPPH; FRAP; RP-HPLC; p- coumaric acid; sinapinic acid
• Language: croatian
• URN:NBN: urn:nbn:hr:217:361548
• Study programme: Title: Experimental Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra eksperimentalne biologije (magistar/magistra eksperimentalne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-03-26 09:59:15