Polifenoli i antioksidativni kapacitet drijenka (Cornus mas L.) i proizvoda od drijenka

master's thesis

• Title (english): Polyphenols and antioxidant capacity in cornelian cherry fruits (Cornus mas L.) and product of cornelian cherry
• Author: Ivana Dujlović
• 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: 2007-03-29, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Istraživanje je provedeno na plodovima drijenka nepoznate sorte te na sirupima i nektaru od drijenka. U ovom radu određeni su ukupni te pojedinačni fenolni spojevi. Ukupni antocijani određivani su spektrofotometrijski, a pojedinačni antocijani, fenolne kiseline, flavan-3-oli i flavonoli primjenom HPLC metode uz UV-PDA detekciju. Antioksidativni kapacitet, plodova i proizvoda od drijenka, određen je primjenom FRAP, DPPH i ABTS metodama. Ujedno je na uzorcima provedeno senzorsko određivanje primjenom kvantitativne deskriptivne analize. Ova sorta drijenka bogat je izvor fenolnih spojeva. Iz skupine antocijana u najvećoj koncentraciji identificiran je pelargonidin-3-galaktozid, a u padajućem nizu slijede cijanidin-3-galaktozid,pelargonidin-3-glukozid te cijanidin-3-glukozid. Iz skupine fenolnih kiselina u kaši drijenka u najvećoj koncentraciji određena je galna kiselina, a u padajućem nizu slijede vanilinska kiselina, klorogenska kiselina, ferulinska kiselina, neoklorogenska kiselina, derivat hidroksicimetne kiseline te p-kumarinska kiselina i kava kiselina. Značajne skupine fenolnih spojeva predstavljaju skupina flavan-3-ola među kojima se ističu (+)-katehin i (-)-epikatehin i skupina flavonola među kojima se ističu kvercetin-3-glukozid i kvercetin-3-rutinozid. Najveće vrijednosti antioksidativnog kapaciteta određene su u kaši drijenka. Na temelju senzorske analize, kvantitativnom deskriptivnom metodom utvrđeno je da nektar ima najbolja senzorska svojstva.

Abstract (english)

Analysis were made in cornelian cherry fruit and in its products, syrups and nectar. The aim of this study was to determined the total and single polyphenols in cornelian cherry fruits and in its products. The total anthocyanins were measured spectrophotometrically, whereas a HPLC method was used for the analysis of individual anthocyanins, phenolic acids, flavan-3-ols and flavonols. Three different methods (DPPH, FRAP and ABTS) were used to determined the antioxidant capacity. The aim was also to perform sensory evaluation by using the quntitative descripton analysis. Anthocyanins were determined as pelargonidin-3-galactoside (the highest concentration), cyandin-3-galactoside, pelargonidin-3-glucoside and cyandin-3-glucoside (the lowest concentration). The phenolics acids, determined in investigated samples by HPLC method, in decreasing sequence are: gallic acid, vanillic acid, chlorogenic acid, ferulic acid, neochlorogenic acid, derivative of hydroxycinnamic acid, p-coumaric acid and caffeic acid. Flavan-3-ols ((-)-epicatechin and (+)-catechin) and flavonols (quercetin-3-glucoside i quercetin-3-rutinoside) are significant groups of polyphenols and they were also determined by HPLC method. Generally, this study showed the decrease of all phenolic compounds within processing of cornelian cherry fruits into products. According to DPPH, FRAP and ABTS method, all samples posses an evident antioxidant capacity. The quntitative descripton analysis confirmed that investigated cornelian cherry fruits is high quality, especially nectar.

• Keywords: Cornus mas; drijenak; polifenoli; antioksidativni kapacitet; HPLC metoda
• Keywords (english): Cornus mas; cornelian cherry; polyphenols; antioxidant activity; HPLC method
• Language: croatian
• URN:NBN: urn:nbn:hr:159:203695
• 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: 2017-09-06 11:18:50