Izolacija bioaktivnih spojeva iz koprive primjenom ubrzane ekstrakcije otapalima pri povišenom tlaku

master's thesis

• Title (english): Accelerated solvent extraction of bioactive compounds from nettle (Urtica dioica) leaves
• Author: Marta Maras
• Mentor: Danijela Bursać Kovačević (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: 2019-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada bio je ispitati učinkovitost ekstrakcije bioaktivnih spojeva iz listova koprive (Urtica dioica L.) primjenom ubrzane ekstrakcije otapalima pri povišenom tlaku (ASE). Uz etanol kao ekstrakcijsko otapalo, ispitivani su sljedeći parametri ekstrakcije: (i) statičko vrijeme ekstrakcije (5 i 10 min); (ii) broj ciklusa ekstrakcije (1, 2, 3 i 4 ciklusa); te (iii) temperatura (20 i 50 °C). U dobivenim ekstraktima provedeno je spektrofotometrijsko određivanje ukupnih fenola, karotenoida te klorofila a i b. Rezultati istraživanja su pokazali kako sva tri varirana parametra značano utječu na masene udjele ispitivanih spojeva (p ≤ 0,01). Maseni udjeli ukupnih fenola određeni su u rasponu 106,44 do 739,72 mg 100 g-1, klorofila a od 116,44 do 490,42 mg 100 g-1, klorofila b od 44,88 do 166,85 mg g-1 te karotenoida od 36,62 do 133,99 mg 100 g-1. Najveći prinosi dobiveni su pri sljedećim uvjetima ekstrakcije: ukupni fenoli, karotenoidi i klorofil a pri temperaturi 50 °C i 4 ekstrakcijska ciklusa od 10 min; klorofil b pri temperaturi ekstrakcije od 50 °C, 3 ekstrakcijska ciklusa od 10 min.

Abstract (english)

The aim of this study was to investigate the extraction efficiency of the bioactive compounds from stinging nettle (Urtica dioica L.) leaves by using Accelerated Solvent Extraction (ASE). Ethanol was used as the extraction solvent and the following extraction parameters were investigated: (i) static extraction time (5 and 10 min); (ii) number of extraction cycles (1, 2, 3 and 4 cycles); and (iii) temperature (20 and 50 °C). All extracts were spectrophotometrically evaluated in terms of total phenols, carotenoids and chlorophylls a and b. The results of the research have shown that all extraction parameters significantly affected the concetrations of the investigated compounds (p≤0,01). Mass fractions of total phenols ranged from 106,44 to 739,72 mg GAE 100 g-1, chlorophyll a from 116,44 to 490,42 mg 100 g-1, chlorophyll b from 44,88 to 166,85 mg 100 g-1 and carotenoids from 36,62 to 133,99 mg 100 g-1. The highest yields were obtained under the following extraction conditions: extraction temperature of 50 °C and four 10 minute cycles for total phenols, carotenoids and chlorophyll a and extraction temperature of 50 °C and three 10 minutes cycles for chlorophyll b.

• Keywords: kopriva; ASE ekstrakcija; ukupni fenoli; karotenoidi; klorofili
• Keywords (english): stinging nettle; ASE extraction; total phenols; carotenoids; chlorophylls
• Language: croatian
• URN:NBN: urn:nbn:hr:159:145728
• 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: 2020-01-28 13:05:39