diplomsko delo
Ana Brdnik (Author), Anja Klančnik (Reviewer), Tatjana Košmerl (Mentor)

Abstract

V diplomskem delu smo spremljali, kakšen vpliv ima fermentacijska temperatura na potek alkoholne fermentacije belega mošta, pri tem pa smo uporabili dve različni vrsti vinskih kvasovk kot starterski kulturi. Poskus smo izvajali v dveh paralelkah, in sicer: dva vzorca mošta ter kontrolni vzorec smo inkubirali pri 20 °C, druga dva vzorca mošta pa pri 10 °C. Potek alkoholne fermentacije smo spremljali gravimetrično, preko spremljanja koliko ogljikovega dioksida se je sprostilo v določenem časovnem obdobju. Iz tega podatka smo preračunali, koliko sladkorjev so kvasne celice že prevrele v etanol in ogljikov dioksid, hkrati smo izrisali tudi krivulje poteka alkoholne fermentacije in fermentacijske kinetike. Fermentacijska kinetika se med paralelkama precej razlikuje. Vzorca, ki sta bila na temperaturi 20 °C, sta hitro dosegla največjo oddano koncentracijo ogljikovega dioksida, medtem ko sta bila vzorca pri fermentacijski temperaturi 10 °C pričakovano počasnejša. Po zaključeni alkoholni fermentaciji smo vzorce pridelanih mladih vin analizirali. Zanimale so nas razlike v kemijski sestavi vin, ki so fermentirala pri različnih temperaturah. Prišli smo do zaključkov, da je temperatura alkoholne fermentacije 10 °C prenizka temperatura in tudi po prestavitvi fermentacijskih stekleničk na toplejše mesto, je mošt fermentiral predolgo (36 dni). Kljub temu pa ni velikih odstopanj v kemijski sestavi med paralelkama vina.

Keywords

mošt;vinske kvasovke;Saccharomyces;ne-Saccharomyces;alkoholna fermentacija;temperatura fermentacije;fizikalnokemijske lastnosti;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [A. Brdnik]
UDC: 663.221:663.252/.253:543.2
COBISS: 26304003 Link will open in a new window
Views: 629
Downloads: 117
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Other data

Secondary language: English
Secondary title: Influence of temperature on the course of fermentation
Secondary abstract: In this work we monitored the influence of fermentation temperature on the course of alcoholic fermentation of white must, using two different strains of wine yeast as starter cultures. The experiment was performed in two duplicates: two grape must samples and the control sample were incubated at 20 °C and the other two must samples at 10 °C. We monitored the course of alcoholic fermentation gravimetrically - how much carbon dioxide was released over a certain period of time. From these data, we calculated how much sugar the yeast cells had already fermented into ethanol and carbon dioxide, and at the same time we got the graphs of the fermentation curve and fermentation kinetics. The fermentation kinetics varied considerably between the duplicates. The warm specimens quickly reached the highest released carbon dioxide concentration while the cold specimens fermented slowly. After the alcoholic fermentation was completed, we put the samples of the produced wines for analysis, as we were interested in the differences in the chemical composition of the wines fermented at different temperatures. We concluded that the temperature of alcoholic fermentation was too low by 10 °C and even after moving the fermentation bottles to a warmer place, the must fermented for too long (36 days). However, there are no signicifant differences in chemical composition between the wine duplicates.
Secondary keywords: must;wine yeasts;Saccharomyces;non-Saccharomyces;alcoholic fermentation;fermentation temperature;physicochemical properties;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VI, 22 f.
ID: 11981294