Oksidacija spojeva odgovornih za aromu vina

master's thesis

• Title (english): Oxidation of wine aroma compounds
• Author: Mia Šiško
• Mentor: Leo Gracin (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology and Analysis of Wine); Zagreb
• Defense date and country: 2015-07-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Lako hlapive tvari, esteri i viši alkoholi, u mladom vinu uvelike određuju njegovu kvalitetu. Starenjem vina dolazi do promjene njihovih koncentracija, čime se mijenja aromatski profil vina. Vino gubi voćni karakter mirisa i tržišnu prihvatljivost. Cilj ovog rada bio je utvrditi na koji način dolazi do navedenih promjena, te odrediti potencijalne inhibitore reakcija. Pripremljene su model otopine vina u kojima su praćene promjene koncentracija estera u ovisnosti o različitim pH vrijednostima te pod utjecajem oksidansa. Model otopine vina analizirane su analitičkom metodom plinske kromatografije s plameno-ionizacijskim detektorom i „Headspace“ automatskim uzorkivačem. Rezultati analiza pokazali su da različite pH vrijednosti utječu na koncentraciju estera u model otopinama, točnije da niže pH vrijednosti ubrzavaju hidrolizu acetatnih estera, te da su esteri, nosioci arome vina, podliježni reakcijama oksidacije. Askorbinska i galna kiselina, suprotno očekivanom, nisu se pokazale kao djelotvorni inhibitori oksidacije estera.

Abstract (english)

Volatile esters and higher alcohols in the young wine largely determine its quality. Aging of the wine leads to changes of ester concentration, therefore it changes the aromatic profile of wine. Wine loses its fruity character and market acceptability. The aim of this study was to determine how the mentioned changes occur, and identify potential inhibitors of these reactions. Wine model solutions were prepared in order to observed changes in concentration of esters dependent on different pH values, and under the influence of an oxidant. Model solutions were analysed using gas chromatography with flame ionisation detector (FID) and "Headspace" automatic sampler. The analysis results showed that different pH values affect the concentration of esters in model solutions, more precisely that lower pH value accelerates the hydrolysis of the acetate ester, and that esters, wine flavor carriers, are under the influence of oxidation reactions. Ascorbic and gallic acid, contrary to expectations, have not been shown effective as inhibitors of the ester oxidation.

• Keywords: aroma vina; esteri; plinska kromatografija; hidroliza; oksidacija
• Keywords (english): wine aroma; esters; gass chromatografy; hydrolysis; oxidation
• Language: croatian
• URN:NBN: urn:nbn:hr:159:417384
• 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: Access restricted to students and staff of home institution
• Created on: 2017-05-05 09:19:30