Primjena kelirajućeg agensa u ekstrakciji pektina iz otpadne biomase crvenog luka

master's thesis

• Title (english): Application of the chelating agents in the extraction of pectin from onion biomass waste
• Author: Lucija Pokec
• Mentor: Draženka Komes (mentor)
• 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: 2017, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Agroindustrijski otpad smatra se vrijednom sekundarnom sirovinom za razne industrijske procese i izdvajanje različitih funkcionalnih sastojaka zbog velike dostupnosti i zanimljivog kemijskog sastava pri čemu istovremeno dolazi do smanjenja ekološkog opterećenja i troškova. Cilj ovog rada bio je istražiti primjenu kelirajućeg agensa (EDTA) te utjecaj ekstrakcijskih parametara na prinos i sastav pektina iz otpadne biomase crvenog luka. U svrhu karakterizacije pektinskih izolata i ostataka nakon ekstrakcije razvijena je metoda tekućinske kromatografije visoke djelotvornosti (HPLC). HPLC metodom određeno je 7 neutralnih šećera i 2 uronske kiseline, pri čemu strukturni ugljikohidrati zauzimaju većinu ugljikohidratne frakcije. Najveći prinos pektinskih tvari dobiven je u uzorku koji je ekstrahiran pri povišenoj temperaturi i povišenoj pH-vrijednosti otapala. Svi pektinski izolati imali su dominantan udjel galakturonske kiseline, stoga je najzastupljeniji tip pektina homogalakturonan, dok je u ostacima nakon ekstrakcije dominirala glukoza. U radu su prikazane i bilance za karakteristične pektinske monosaharide (galakturonska kiselina, ramnoza, galaktoza i arabinoza). Ukupnom iskorištenju galakturonske kiseline pogoduju povišena temperatura i niže pH-vrijednosti, dok izdvajanju ramnoze, galaktoze i arabinoze pogoduju niža temperatura i niži pH. S obzirom na ukupno iskorištenje prikazana su i relativna iskorištenja pojedinih monosaharida unutar pektinske frakcije te frakcije ostatka.

Abstract (english)

Agroindustrial waste is considered to be a valuable secondary raw material for various industrial processes and the separation of various functional constituents due to its high availability and an interesting chemical composition, while simultaneously reducing environmental burden and costs. The aim of this paper was to investigate the use of a chelating agent (EDTA) and the influence of extraction parameters on the yield and composition of pectin from onion biomass waste. For the purpose of characterisation of pectin isolates and of residues after extraction, a characteristic method of high performance liquid chromatography (HPLC) was developed. The HPLC method determines 7 neutral sugars and 2 uronic acids, whereby the structural carbohydrates occupy most of the carbohydrate fraction. The highest yield of pectin substances was obtained in the sample extracted at elevated temperature and elevated pH of solvent. All pectin isolates had a dominant share of galacturonic acid, hence the most common type of pectin is homogalacturonan, whereas in the residues after extraction dominated glucose. This paper also presents balances for characteristic pectin monosaccharides (galacturonic acid, rhamnose, galactose and arabinose). Total utilization of galacturonic acid is favoured by elevated temperature and lower pH, whereas rhamnose, galactose and arabinose favor lower temperature and lower pH. Considering total utilization, the relative utilization of certain monosaccharides within the pectin fraction and residues fraction is also shown.

• Keywords: agroindustrijski otpad; ekstrakcija; galakturonska kiselina; HPLC; pektinske tvari
• Keywords (english): agroindustrial waste; extraction; galacturonic acid; HPLC; pectic substances
• Language: croatian
• URN:NBN: urn:nbn:hr:159:316294
• 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: 2017-11-13 10:46:37