Isolation of polyphenols, proteins and enzymes from citrus peel with deep eutectic solvents

Konzumacija i prerada agruma u prehrambenoj, kozmetičkoj i farmaceutskoj industriji svakodnevno raste zahvaljujući bogatom nutritivnom sastavu, no time raste i količina otpada u obliku kore, koštica i pulpe. Kora naranče je neiskorišten izvor šećera, enzima i bioaktivnih komponenti. Cilj ovog rada je ispitati mogućnost primjene eutektičkog otapala kolin-klorid:glukoza sa 30 % 50% i 80% vode (w/w) u iskorištenju punog potencijala navedenog otpada kroz održivi proces. Eutektička otapala su biorazgradiva, niske su cijene i lako se pripremaju. Ispitano eutektičko otapalo sa 30 % i 50 % vode se pokazalo produktivno pri ekstrakciji polifenola iz otpadne kore naranče, dok je pokazalo vrlo slabu uspješnost pri ekstrakciji proteina. Ispitana je i aktivnost enzima pektin-esteraze ekstrahirane iz kore naranče pri čemu je navedeni enzim pokazao veću aktivnost samo u eutektičkom otapalu sa 30 % vode. Otapalo ChClGlc se pokazalo značajno boljim u enantioselektivnoj hidrolizi (R,S)-1-feniletil-acetata primjenom hidrolitičkih enzima iz narančine kore u odnosu na pufer, sa najvećim iskorištenjem u eutektičnom otapalu sa 80 % vode.Consumption and processing of citrus fruits in the food, cosmetic and pharmaceutical industries are increasing daily thanks to its rich nutritional composition, but with it waste in the form of peel inevitably increases. Orange peel is a rich source of sugar, enzymes and bioactive components. The aim of this thesis is to examine the possibility of using Deep Eutectic Solvent (DES) choline-chloride:glucose with 30%, 50% and 80% water (w/w) in the exploitation orange peel waste through a sustainable process. DES are biodegradable, low in cost and easy to prepare. Tested DES with 30% and 50% water proved to be good in the extraction of polyphenols, while it showed a poor protein extraction effect. The activity of the pectin-esterase enzyme extracted from orange peel was also examined, where pectin-esterase showed higher activity only in ChClGlc 30%. The enantioselective hydrolysis of (R, S)-1-phenylethyl acetate using orange peel hydrolytic enzymes all ChClGlc were significantly better comparing to buffer, especially ChClGlc 80%