Optimizacija ekstrakcije polifenolnih spojeva i pigmenata iz lista koprive (Urtica dioica L.) primjenom ultrazvuka

master's thesis

• Title (english): Optimization of ultrasound assisted extraction of phenolic compounds and pigments from nettle leaves (Urtica dioica L.)
• Author: Marijana Jurković
• Mentor: Zoran Zorić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for drying Technologies and monitoring of biologically active compounds); Zagreb
• Defense date and country: 2019-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada bila je optimizacija vremena ekstrakcije i amplitude ultrazvuka na učinkovitost izolacije fenolnih spojeva, klorofila a i b te karotenoida iz listova koprive primjenom ekstrakcije potpomognute ultrazvukom. Ekstrakcija je provedena pri konstantnoj frekvenciji od 26 kHz i promjeru sonde (2 mm), a izvori varijacije bili su: amplituda ultrazvuka (25, 50, 75 i 100 %) i vrijeme ekstrakcije (5, 10, 15, 20, 30 i 40 minuta). Optimalnim uvjetima za ekstrakciju ukupnih fenola pokazalo se vrijeme ekstrakcije od 40 minuta pri amplitudi od 75 % . Isto vrijeme je optimalno i za ekstrakciju klorofila a, ali pri amplitudi 100 %. Za ekstrakciju klorofila b i karotenoida, optimalno vrijeme je 30 minuta te amplituda 75 %. Navedeni optimalni uvjeti pokazuju da je za ekstrakciju ukupnih fenola i klorofila a bolja duţa ekstrakcija pri višim amplitudama, dok je za ekstrakciju klorofila b i karotenoida bolje provesti kraću ekstrakciju pri nešto niţim amplitudama ultrazvuka.

Abstract (english)

The aim of this study was to determine the optimal conditions for efficiency of phenolic compounds, chlorophyll a and b and carotenoids isolation using ultrasound – assisted extraction from nettle leaves. The extraction was performed at constant frequency (24 kHz) and the 2 mm probe. Sources of variation were: the amplitude (25, 50, 75 and 100 %) and the extraction time (5, 10, 15, 20, 30 and 40 minutes). Results showed that optimal conditions for phenolic compounds extraction were the extraction time 40 min and 75 % amplitude. The same time was optimal for chlorophyll a extraction, but the amplitude was 100 %. For chrolophyll b and carotenoids the optimal extraction time was 30 min and 75 % amplitude. These optimal conditions indicate that is better to use longer time and higher amplitude for phenolic compounds and chlorophyll a extraction, but for the extraction of chlorophyll b and carotenoids shorter time and lower amplitude show better results.

• Keywords: kopriva; ultrazvuk; ekstrakcija; polifenoli; pigmenti
• Keywords (english): nettle; ultrasound; extraction; phenolics; pigments
• Language: croatian
• URN:NBN: urn:nbn:hr:159:852246
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-02-03 11:04:10