Određivanje polifenolnih spojeva i antioksidacijskog kapaciteta u liofiliziranim jagodama (Fragaria x ananassa Duch.)

master's thesis

• Title (english): Determination of phenolic compounds and antioxidant capacity in freeze dried strawberries (Fragaria x ananassa Duch.)
• Author: Ana Šeler
• Mentor: Verica Dragović-Uzelac (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Fruits and Vegetables Preservation and Processing); Zagreb
• Defense date and country: 2007-12-06, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Istraživanje je provedeno na plodovima pet sorti liofiliziranih jagoda. U ovom radu određivani su biološki aktivni spojevi, tj. ukupni te pojedinačni fenolni spojevi. Ukupni fenolni spojevi određivani su spektrofotometrijski, dok su pojedinačni antocijani, fenolne kiseline, flavan-3-oli i flavonol-3-glikozidi određivani primjenom HPLC metode uz UV/VIS-PDA detekciju. Za određivanje antioksidacijskog kapaciteta korištene su tri različite metode: DPPH, ABTS i FRAP metoda. Dobiveni rezultati pokazuju da je svih pet sorti liofiliziranih jagoda dobar izvor fenolnih spojeva, osobito antocijana. Antocijani određeni u ispitivanim uzorcima su: cijanidin-3-glukozid, pelargonidin-3-glukozid i pelargonidin-3-rutinozid, od kojih je pelargonidin-3-glukozid bio najzastupljeniji. Iz skupine fenolnih kiselina u gotovo svim uzorcima liofilirziranih jagoda najzastupljenija je bila klorogenska kiselina, a najmanje zastupljena kava kiselina. U ispitivanim sortama jagoda određen je značajan antioksidacijski kapacitet, ali dobra povezanost između antioksidacijskog kapaciteta i količine različitih skupina fenolnih spojeva nije utvrđena.

Abstract (english)

Five different freeze dried strawberry cultivars were investigated and biologically active compounds, total and single phenolic compounds were determined. Total phenol content was determined by spectroscopic method while single phenolics were determined by using highperformance liquid chromatography (HPLC) with UV/VIS-PDA Detection. Three different methods (DPPH, ABTS and FRAP) were used to determine the antioxidant capacity. Obtained results showed that all five investigated strawberry cultivars are good source of phenolic compounds, especially anthocyanins. Determined anthocyanins are: cyanidin-3-glucoside, pelargonidin-3-glucoside and pelargonidin-3-rutinoside, and pelargonidin-3-glucoside was the most presented anthocyanin. Among determined phenolic acids, chlorogenic acid was determined in the highest concentrations, while caffeic acid was determined in the lowest concentrations. In all investigated strawberry samples remarkable antioxidant capacity was observed, but amonts of different group of polyphenols was nut in corelation with antioxidant capacity.

• Keywords: antioksidacijski kapacitet; fenolni spojevi; HPLC metoda; jagoda; liofilizacija
• Keywords (english): antioxidant activity; freeze drying; HPLC method; polyphenols; strawberry
• Language: croatian
• URN:NBN: urn:nbn:hr:159:165413
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-05 10:08:43