Utjecaj ekstrakcije mikrovalovima na izolaciju ukupnih fenola i hidroksicimetnih kiselina cvijeta i lista gloga

master's thesis

• Title (english): The influence of microwave assisted extraction on the isolation of total phenols and hydroxycinnamic acids from the flower and leaf of hawthorn
• Author: Mia Čagalj
• 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: 2015-09-21, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cvijet i list gloga bogat su izvor brojnih bioaktivnih spojeva, a uspješnost njihove izolacije ovisi o primjenjenoj metodi te uvjetima ekstrakcije. Osim klasičnih metoda sve više se ispituju i druge metode ekstrakcije poput ekstrakcije potpomognute mikrovalovima. Cilj ovog istraživanja bio je ispitati utjecaj ekstrakcijskog otapala (etanol i metanol), vodene otopine otapala (30%, 50%, 70%), temperature (45°C, 55°C, 65°C) i vremena (2, 4, 6, 8, 10 minuta) ekstrakcije na učinkovitost izolacije ukupnih fenola, hidroksicimetnih kiselina iz lista i cvijeta gloga (Crataegi folium cum flore) primjenom ekstrakcije potpomognute mikrovalovima, te odrediti antioksidacijski kapacitet u dobivenim ekstraktima. Ekstrakcija je provedena pri snazi mikrovalova od 150-300 W. Utvrđeno je da se najveća učinkovitost izolacija ukupnih fenola postiže sa 70% etanolom, pri temperaturi od 45°C kroz vrijeme ekstrakcije 2 minute, dok je najveća koncentracija hidroksicimetnih kiselina postignuta sa 50% etanolom, pri temperaturi od 65°C kroz vrijeme ekstrakcije 8 minuta. Vrijednosti antioksidacijskog kapaciteta su u pozitivnoj korelaciji sa količinom fenolnih spojeva.

Abstract (english)

The flower and leaf of hawthorn are a rich source of many bioactive compounds. The success of their isolation depends on the applied extraction method. Alternative methods, like microwave assisted extraction, are being examined. The aim of this study was to investigate the influence of extraction solvents (ethanol and methanol), their water aqueous (30%,50%,70%), extraction temperature (45°C, 55°C, 65°C) and the treatment duration (2, 4, 6, 8, 10 minutes) on the efficacy of isolation of total phenols, hydroxycinnamic acids from the flower and leaf of hawthorn (Crataegi folium cum flore) and the determination of the antioxidant capacity from the extracts. The extraction was carried out with the microwave power of 150-300W. The best isolation of total phenols was determined with the use of 70% ethanol, temperature of 45°C and at 2 minutes. The best isolation of hydoxycinnamic acids was determend with at 8 minutes, 65°C and with the use of 50% ethanol. The antioxidant capacity is in positive correlation with the amount of total phenols.

• Keywords: cvijet i list gloga; ukupni fenoli; hidroksicimetne kiseline; ekstrakcija potpomognuta mikrovalovima; antioksidacijski kapacitet
• Keywords (english): flower and leaf of hawthorn; total phenols; hydroxycinnamic acids; microwave assisted extraction; antioxidant capacity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:774746
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-04-28 08:51:41