Določanje vsebnosti kovin in pektina v moštu med alkoholno fermentacijo

Zorko, David (author), Kolar, Mitja (mentor)

Vsebnosti kovin v vinu ima pomemben vpliv na potek fermentacije in določa končne lastnosti vina. Zato sem določal vsebnost izbranih kovin v vzorcih mošta šmarnice. Vzorci so bili odvzeti ob različnih fazah procesa alkoholne fermentacije. Koncentracije kovin sem določal s pomočjo tehnike ICP-OES. Poleg kovin sem v moštu določal tudi koncentracijo pektina. Pektin sem s pomočjo encima pektin liaze razgradil na enote galakturonske kisline, katerim sem meril absorbanco z absorpcijsko spektrometrijo. Spremljal sem trende spreminjanja koncentracij kovin Al, B, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Rb, Sr in Zn ter pektina med alkoholno fermentacijo. Opazil sem trend nižanja koncentracije kovin, ki je posledica izločanja soli, kompleksacije in vezave na trdne ostanke kvasovk. Drugi opažen trend višanja koncentracij nekaterih kovin je sovpadal s trendom raztapljanja pektina v moštu.

• Language: Slovenian
• Keywords: mošt, alkoholna fermentacija, kovine, pektin, ICP-OES, UV-Vis
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-131635
• COBISS.SI-ID: 87689475
• Publication date in RUL: 30.09.2021

Secondary language

• Language: English
• Title: Determining the contents of metals and pectin in must during alcoholic fermentation

Abstract

The contents of metals in wine has a significant impact on the process of fermentation and determines the final properties of wine. That is why I determined the concentrations of selected metals in samples of wine must of "šmarnica" sort. The samples were taken at different phases of the alcoholic fermentation process. The concentration of metals was determined using the ICP-OES technique. I also determined the concentration of pectin in wine must. I split the pectin into units of galacturonic acid using pectin lyase enzyme and measured the absorbance using absorption spectrometry. I observed the concentration changes of metals Al, B, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Rb, Sr and Zn and pectin during alcoholic fermentation. I noticed a trend of decreasing concentration of metals, which is a result of salt precipitation, complexation and bonding to solid lees. Another trend of increasing concentrations of some metals is similar to the trend of desolvation of pectin in wine must.

• Keywords: wine must, alcoholic fermentation, metals, pectin, ICP-OES, UV-Vis