Fenolni spojevi i antioksidativna aktivnost u plodovima trnine te u nektarima i sirupima trnine (Prunus spinosa L.)

master's thesis

• Title (english): Phenolic compounds and antioxidant activity in blackthorn fruits (Prunus spinosa L.) and in their nectars and syrup
• Author: Monika Pavlić
• 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: 2006-11-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U plodu trnine (Prunus spinosa L.) dva različita stupnja zrelosti, nektarima i sirupu trnine analizirani su fizikalno-kemijski sastav (ukupna i topljiva suha tvar, pH, ukupna kiselost, šećeri), fenolni spojevi (ukupni i pojedinačni), antioksidativna aktivnost i senzorske karakteristike. Ukupni fenoli, flavonoidi i neflavonoidi određeni su primjenom spektrofotometrijskih metoda, dok su pojedinačni fenolni spojevi (flavan-3-oli, flavonoli, procijanidini i hidroksicimetne kiseline) određeni primjenom tekućinske kromatografije visoke djelotvornosti uz UV- Photo Dioda Array detekciju (HPLC-UV/PDA). Antioksidativna aktivnost plodova i proizvoda mjerena je spektrofotometrijski primjenom 1,1-difenil-2-pikrilhidrazil radikala (DPPH) i 2,2`,-azinobis(3-etilbenzotiazolin-6-sulfonska kiselina) radikal kationa (ABTS). Najveća količina ukupnih i pojedinačnih fenolnih spojeva određena je u plodu trnine ubrane poslije prvog mraza, u listopadu. Njihova količina tijekom prerade u nektare i sirup bitno se smanjila. Plodovi trnine ubrani u studenom također su sadržavali manje količine fenolnih spojeva. U istraživanim uzorcima najzastupljeniji fenolni spojevi bili su: neoklorogenska kiselina, (-)-epikatehin i kvercetin-3-rutinozid. U svim uzorcima određena je visoka antioksidativna aktivnost, a naročito u plodovima trnine ubranim u listopadu. Rezultati dobiveni u ovom radu pokazuju da plodovi trnine i proizvodi dobiveni iz nje mogu biti važan izvor biološki aktivnih spojeva s izrazitom antioksidativnom aktivnošću.

Abstract (english)

Blackthorn (Prunus spinosa L) fruits harvested at two stages of maturity, their nectars and syrup, were assayed for physico-chemical composition (total and soluble dry matter, pH, total acidity and sugars), phenolics (total and single), antioxidant activity and sensory characteristic. Total phenols, flavonoids and non-flavonoids were determined using spectrophotometric methods, whereas single phenols (flavan-3-ols, flavonols, procyanidins and hydroxycinamic acid) were determined using HPLC with UV-VIS Dioda Array detection. Antioxidant activity was evaluated by spectrophotometric methods against stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2`,-azino-di(3-ethylbenzothiazolin-6-sulfonic acid) radical cation (ABTS). The highest amount of total and single phenolic compounds was determined in blackthorn fruits harvested after 1st frost, in October. Their amounts significantly decreased during processing into nectars and syrup. Blackthorn fruits harvested in November also contained remarkable lower amounts of phenolic compounds. The most abundant phenolics in investigated samples were: neochlorogenic acid, (-)-epicatechin and quercetin-3-rutinoside. In all investigated samples an evident antioxidant activity was observed, especially in blackthorn fruits harvested in October. The results obtained in this study suggested that blackthorn fruits and their products may be important source of biologically active compounds with pronounced antioxidant activity.

• Keywords: antioksidativna aktivnost; fenolni spojevi; HPLC metoda; nektari; sirup; trnina.
• Keywords (english): antioxidant activity; phenolic compounds; HPLC method; nectar; syrup; blackthorn
• Language: croatian
• URN:NBN: urn:nbn:hr:159:677789
• 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: 2017-09-08 07:35:29