Utjecaj ekstrakcijskih uvjeta na izdvajanje bioaktivnih spojeva iz ljuske kakaovog zrna i ljuske oraha

master's thesis

• Title (english): The impact of extractions conditions on bioactive compounds extractability from cocoa bean shell and walnut shell
• Author: Sonja Vrtar
• Mentor: Draženka Komes (mentor)
• Committee member: Božidar Šantek (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Chemistry and Technology of Carbohydrates and Confectionery Products); Zagreb
• Defense date and country: 2021-07-06, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovoga rada bio je istražiti ljusku kakaovog zrna te ljusku oraha kao potencijalne inovativne izvore polifenola i metilksantina te ispitati učinkovitost konvencionalnih i inovativnih tehnika ekstrakcije u izdvajanju istih. Ekstrakti su pripremljeni korištenjem vodeno - etanolnih otopina, u kombinaciji s tri konvencionalne tehnike ekstrakcije (infuzija, dekokcija, maceracija) te ekstrakcije potpomognute ultrazvukom. Dobivenim ekstraktima određen je udjel ukupnih polifenola, ukupnih proantocijanidina i antioksidacijski kapacitet primjenom spektrofotometrijskih metoda, kao i udjel pojedinačnih spojeva primjenom HPLC-DAD analize. Najviši udjeli mjerenih parametara određeni su u ekstraktima pripremljenima dekokcijom i infuzijom, dok je primjena ultrazvuka rezultirala nižom ekstrakcijskom učinkovitošću. Od bioaktivnih spojeva u ljusci kakaovog zrna dominirali su teobromin (0,66 %) i proantocijanidini (0,13 %). U ljusci oraha, uz proantocijanidine, najviše su bili zastupljeni derivati hidroksibenzojevih kiselina, među kojima se isticala elaginska kiselina (0,015 %).

Abstract (english)

The aim of this study was to investigate cocoa bean shell and walnut shell as potential innovative sources of polyphenols and methylxanthines, and to evaluate the effectiveness of conventional and innovative extraction methods in terms of their isolation. The extracts were prepared using aqueous - ethanolic solutions, combined with three conventional extraction techniques (infusion, decocation, maceration) and ultrasonically assisted extraction. The obtained extracts were evaluated for total polyphenols and total proanthocyanidins contents, as well as the antioxidant capacity, using spectrophotometric methods, while the contents of individual compounds was determined using HPLC-DAD analysis. The highest results of measured parameters were determined in extracts prepared by decoction and infusion , while the application of ultrasound resulted in generally lower extraction efficiencies. Among the bioactive compounds in cocoa bean shell, theoboromine (0,66 %) and proanthocyanidins (0,13 %) dominated. In addition to proanthocyanidins, hydroxybenzoic acid derivatives were the most represented in the walnut shell, among which especially ellagic acid (0,015 %).

• Keywords: ekstrakcija; ljuska kakaovog zrna; ljuska oraha; metilksantini; polifenoli
• Keywords (english): cocoa bean shell; extraction; methylxanthines; polyphenols; walnut shell
• Language: croatian
• URN:NBN: urn:nbn:hr:159:766534
• 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: 2021-09-06 09:59:19