Esterifikacija i hidroliza spojeva odgovornih za aromu vina

master's thesis

• Title (english): Esterification and hydrolisis of aroma defining compounds
• Author: Iva Repac
• 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: 2013-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Aroma vina je jedna od bitnih komponenti njegove kvalitete. Čini je stotine spojeva, no posebice bitni i značajni su esteri. Većinski udio estera nastaje tijekom alkoholne fermentacije metabolizmom kvasaca. Tijekom starenja vina njihov udio u vinu se mijenja jer neki nastaju kemijskom esterifikacijom te im se koncentracije povećavaju, dok neki hidroliziraju čime im se udio u vinu smanjuje. Kako bismo uvidjeli na koji se način reakcije hidrolize i esterifikacije odvijaju u vinu te koji faktori mogu utjecati na njih, izrađene su modelne otopine vina. Analiziravši ih analitičkom metodom plinske kromatografije s plameno-ionizirajućim detektorom i „Headspace“ automatski uzorkivačem, praćene su promjene u koncentracijama etil acetata, izoamil acetata te etil laktata. Navedeni esteri praćeni su i u dvama vinima. Dobiveni rezultati ukazuju na to da veće koncentracije etil acetata nastaju pri većoj koncentraciji alkohola te da je pri višem pH stupanje hidrolize izoamil acetata manji.

Abstract (english)

Wine aroma is very important factor of wine quality and it is composed of hundreds of compounds of which important ones are esters. Esters are mainly produced during alcoholic fermentation by yeasts. During storage and maturation of wine their concentration changes, increasing via chemical esterification or decreasing because of hydrolysis of esters. To explore mechanisms of these reactions in wine and find out which factors can effect them we prepared wine model solutions. We analised samples of model solutions and two wines using gas chromatography with flame ionisation detector (FID) and "Headspace" automatic sampler and observed changes in concentration of following esters: ethyl acetate, isoamyl acetetate and ethyl lacate. Given results show that esterification rate of ethyl aceteta is significantily higer in model solutions whit higher concentration of alchocol and that lower pH favors hydrolisis of isoamyl acetete.

• Keywords: aroma vina; esterifikacija; hidroliza; plinska kromatografija; hlapljivi spojevi
• Keywords (english): wine aroma; esterification; hydrolysis; gas chromatography; volatile compounds
• Language: croatian
• URN:NBN: urn:nbn:hr:159:203973
• 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: 2017-05-04 10:32:06