Utjecaj skladištenja na fenolni sastav i antioksidativnu aktivnost marmelada od jagoda

master's thesis

• Title (english): Influence of storage on fenolic compounds and antioxidative activity in strawberry marmalades
• Author: Sanja Perkovac
• 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: 2007-02-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu uspoređivan je fenolni sastav i antioksidativna aktivnost niskokaloričnih marmelada od jagoda sorti Maya, Queen Elise i Elsanta iz konvencionalnog i ekološkog uzgoja, prije i nakon 6 mjeseci skladištenja. Marmelade su pripremljene kuhanjem u vakuum – kuhaču te skladištene 6 mjeseci u mraku pri 18º C. Usporedbom ispitivanih svojstava prije i nakon 6 mjeseci skladištenja, vidljivo je kako su se količine suhe tvari kod većine marmelada smanjile, količine topljive suhe tvari neznatno porasle, pH vrijednosti ostale približno jednake, a ukupna kiselost je porasla nakon skladištenja. Količine ukupnih fenola, flavonoida i antocijana su se nakon skladištenja smanjile, dok su količine neflavonoida porasle. Antioksidativna aktivnost određivana je pomoću tri metode: DPPH, ABTS i FRAP, a tijekom skladištenja smanjila se kod svih marmelada.

Abstract (english)

The aim of this study was to examine physical and chemical composition, phenolic composition and antioxidative activity of low – calorie marmalades of strawberry varieties Maya, Queen Elise and Elsanta, grown in conventional and organic cultivation, before and after 6 months of storage. Marmalades were prepared under vacuum conditions and were stored for 6 months in the dark at the temperature of 18º C. After 6 months of storage the amounts of solids in marmalades had decreased, amounts of soluble solids had increased, pH values remained similar to the values before storage, and the total acidity had increased. Amounts of total phenolics, flavonoids and anthocyanids have decreased after storing, while the amounts of non-flavonoids have increased. Antioxidative activity was measured by using 3 different methods: DPPH, ABTS and FRAP. During storage the antioxidative activity had decreased in all the marmalades.

• Keywords: fenolni spojevi; antioksidativna aktivnost; antocijani; jagode; marmelada
• Keywords (english): fenolic compounds antioxidative activity; anthocyanins; strawberries; marmalade
• Language: croatian
• URN:NBN: urn:nbn:hr:159:351388
• Study programme: Title: Food Technology; specializations in: Nutrition; Course: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer nutricionizam (diplomirani inženjer prehrambene tehnologije; smjer nutricionizam)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-06 09:36:18