Određivanje antocijana, flavonol glikozida i antioksidacijske aktivnosti u kašama i sokovima drijenka (Cornus mas L.)

master's thesis

• Title (english): Determination of anthocyanins, flavono glicosides and antioxidant activity in cornelian cherry fruits and nectars (Cornus mas, L.)
• Author: Marijana Posavec
• 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: 2006-10-31, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Plodovi dviju sorata drijenka (Cornus mas L.) analizirani su i korišteni za pripremu kašastih sokova.U ovom istraživanju određivani su bioaktivni spojevi, ukupni i pojedinačni antocijani i flavonol glikozidi, kojima plodovi i sokovi drijenka obiluju. Ukupni antocijani određivani su metodom obezbojenja disulfitom, dok su pojedinačni antocijani i flavonol glikozidi određivani primjenom HPLC uz UV-Vis/ PDA detekciju. Za određivanje antioksidacijske aktivnosti korištene su tri različite metode: DPPH, FRAP i ABTS. Senzorske karakteristike plodova drijenka i njihovih proizvoda određene su kvantitativnom deskriptivnom metodom. Dobiveni rezultati pokazuju visoku koncentraciju antocijana u svim ispitivanim uzorcima, a posebno u svježim bobicama drijenka (745,27 mg/L –''D1'' i 1281,63 mg/kg-''D2''). Antocijani određeni u ispitivanim uzorcima primjenom HPLC metode su: cijanidin-3-galaktozid, pelargonidin-3-galaktozid, pelargonidin-3-glukozid, peonidin-3-galaktozid te cijanidin-3-glukozid. Od spomenutih antocijana, koncentracija pelargonidin-3-galaktozida bila je najviša u svim uzorcima. Flavonol glikozidi kvercetin-3-glukozid, kvercetin-3-rutinozid, kvercetin-3-ksilozid u ispitivanim su uzorcima bili određeni u podjednakim koncentracijama, dok je kvercetin-3-ramnozida bilo u jako malim koncentracijama. Općenito, ovo istraživanje pokazuje smanjenje količina svih fenolnih spojeva tijekom obrade plodova drijenka u kašaste sokove. Prema DPPH, FRAP i ABTS metodi, svi uzorci pokazuju značajnu antioksidacijsku aktivnost. Kvantitativna deskriptivna analiza potvrdila je da su istraživani plodovi drijenka visoke kvalitete, a posebno kašasti sokovi s 35% suhe tvari voća u ukupnoj suhoj tvari nektara.

Abstract (english)

Two varieties of cornelian cherry (Cornus mas L.) fruits were analysed and used for preparation of nectars. In this study the most abundant bioactive compounds in cornelian cherry fruits and nectars, the total and single anthocyanins, and flavonol glicosides were determined. Total anthocyanin amount was determined by bisulphite bleaching method, wherease single anthocyanins and flavonol glicosides were determined by using HPLC with UV-Vis/ PDA detection. Three different methods DPPH, FRAP and ABTS were used to determine the antioxidant activity. Sensory characteristic of cornelian cherry fruits and their product were detrmined by quantitative descriptive analysis. The result showed the high concentration of total anthocyanins in all investigated samples, especially in fresh cornelian cherry fruits (745,27 mg/L –D1 and 1281,63 mg/kg-D2).The anthocyanins determined in investigated samples by HPLC method were as follow: cyanidin-3-galactoside, pelargonidin-3-galactoside, pelargonidin-3-glucoside, peonidin-3-galactoside and cijanidin-3-glucoside. Among mentioned anthocyanins pelargonidin-3-glucoside was present in the highest concentration in all samples. Flavonol glicosides quercetin-3-glucoside, quercetin-3-rutinoside, quercetin-3-xyloside were determined in similar concentration in investigated samples, and quercetin-3-rhamnoside in very low concentration. Generally, this study showed the decrease of all phenolic compounds within processing of cornelian cherry fruits into nectars. According to DPPH, FRAP and ABTS method, all samples posses an evident antioxidant activity. The quntitative descripton analysis confirmed that investigated cornelian cherry fruits is high quality, especially nectar which contained 35 % of dry matter fruits in total dry matter of nectar.

• Keywords: antioksidacijska aktivnost; antocijani; drijenak; flavonol-3-glikozidi; HPLC
• Keywords (english): antioxidant activity; anthocyanins; Cornelian cherry; flavonol glicosides; HPLC
• Language: croatian
• URN:NBN: urn:nbn:hr:159:184002
• 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 08:13:51