Određivanje udjela fenolnih spojeva i antioksidativna aktivnost u sokovima mandarine

master's thesis

• Title (english): Determination of phenolics amount and antioxidant activity in mandarina juices
• Author: Valentina Sakač
• Mentor: Branka Levaj (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: 2005-03-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U sokovima mandarine s različitim udjelima voća (50, 65, 80, 100 %) proizvedenim od sorte Kuno određivani su ukupni fenoli, flavonoidi i neflavonoidi, te antioksidativna aktivnost. Navedeni sokovi su proizvedeni bez i s dodatkom 0,2 % askorbinske kiseline, te je u njima ispitana stabilnost fenolnih spojeva tijekom skladištenja. Ukupni fenoli, flavonoidi i neflavonoidi određivani su spektrofotometrijski. Antioksidativna aktivnost određivana je metodom pomoću slobodnog radikala 1,1-difenil-2-pikril-hidrazil-a. Svi ispitivani sokovi mandarine pokazuju značajnu antioksidativnu aktivnost. Tijekom skladištenja (45 dana, pri 4 °C) smanjila se koncentracija fenolnih spojeva u svim sokovima neovisno o udjelu voća ili dodatku askorbinske kiseline. Dobiveni rezultati ukazuju da dodana količina askorbinske kiseline ima mali utjecaj na antioksidativnu aktivnost sokova mandarine tijekom skladištenja.

Abstract (english)

In mandarin nectars with different level of fruit (50, 65, 80, 100 %) produced from cultivar Kuno, total phenols, flavonoids, nonflavonoids and antioxidant activity were determined. The mentioned nectars were produced without and with 0,2 % of ascorbic acid, and in those nectars the stability of phenolic compounds during storage was investigated. Total phenols, flavonoids and nonflavonoids were determined with spectrophotometric method. Antioxidant activity was conducted by method for evaluation of free radical-scavenging activity of food by using 1,1-diphenyl-2-picrylhydrazyl. All investigated mandarin nectars showed remarkable antioxidant activity. After the storage of 45 days at 4 °C temperature, concentration of phenolic compounds minimized in all mandarin nectars. The obtained data indicate the minor role of added shore of ascorbic acid on antioxidant activity of mandarin nectars during storage.

• Keywords: antioksidativna aktivnost; flavonoidi; neflavonoidi; nektar mandarina; prirodni sok od mandarina
• Keywords (english): antioxidant activity; flavonoids; mandarine juice; mandarine nectar; nonflavonoids
• Language: croatian
• URN:NBN: urn:nbn:hr:159:530738
• 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: 2017-09-13 08:49:47