magistrsko delo
Anja Hribernik (Author), Jože Košir (Mentor), Matjaž Finšgar (Co-mentor)

Abstract

Namen magistrskega dela je bila uvedba in optimizacija preskusne metode za določanje stranskih produktov fermentacije v pivu. Preskusno metodo smo primerjali s standardiziranimi metodami določanja stranskih produktov. Med procesom fermentacije piva nastajajo poleg etanola in ogljikovega dioksida tudi lahkohlapni stranski produkti, ki vplivajo na senzorične lastnosti piva. Najpomembnejši stranski produkti, ki nastajajo so estri (etil acetat, izo-amil acetat, 2-feniletil acetat), višji alkoholi (n-propanol, izo-butanol, 2-metilbutan-1-ol, 3-metilbutan-1-ol, 2-fenil etanol), ketoni (butan-2,3-dion, pentan-2,3-dion), aldehidi (acetaldehid) in hlapne žveplove spojine (dimetilsulfid). Najpogosteje jih določamo s plinsko kromatografijo s plamensko ionizacijskim detektorjem (GC-FID), s predhodno destilacijo piva. Preskusno metodo smo optimizirali glede na pogoje okolja laboratorija ter jo tudi validirali. Za določanje smo uporabili metodo z minimalno pripravo in zajemom vzorca iz parne faze z ekstrakcijo na trdnem nosilcu (SPME, angl. solid phase microextraction). Sledila je kvalitativna in kvantitativna določitev s plinsko kromatografijo z masno spektrometrijo (GC-MS). Rezultate meritev vseh metod smo primerjali z validacijskim postopkom s pomočjo statističnih metod. Iz dobljenih kromatogramov in rezultatov analiznih metod lahko zaključimo, da smo uspešno uvedli in optimizirali preskusno metodo – SPME GC-MS. Dokazali smo linearnost, natančnost in točnost analizne metode, določili pa smo tudi LOD in LOQ. Potrdimo lahko tudi selektivnost in specifičnost preskusne metode, saj smo dobili ločene kramotografske vrhove za posamezno analizirano komponento. Z uvedbo preskusne metode smo bistveno skrajšali čas priprave vzorcev in analize, saj vzorcev ni potrebno predhodno destilirati.

Keywords

pivo;stranski produkti fermentacije;validacija;optimizacija;plinska kromatografija;magistrske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [A. Hribernik]
UDC: 663.452(043.2)
COBISS: 77460739 Link will open in a new window
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Downloads: 99
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Other data

Secondary language: English
Secondary title: Optimization and validation of a method for the determination of fermentation byproducts in beer
Secondary abstract: The purpose of the master's thesis was the introduction and optimization of a test method for the determination of fermentation by-products in beer. The test method was compared with standardized by - product determination methods. During the fermentation process of beer, in addition to ethanol and carbon dioxide, volatile by-products are formed, which affect the sensory properties of beer. The most important by-products formed are esters (ethyl acetate, iso-amyl acetate, 2-phenylethyl acetate), higher alcohols (n-propanol, iso-butanol, 2-methylbutan-1-ol, 3-methylbutan-1-ol, 2-phenyl ethanol), ketones (butane-2,3-dione, pentane-2,3-dione), aldehydes (acetaldehyde) and volatile sulfur compounds (dimethylsulfide). They are determined by gas chromatography with a flame ionization detector (GC-FID) with pre-distillation of beer. The test method was optimized according to the environmental conditions of the laboratory and was also validated. For determination, we used the method with minimal preparation and capture of the sample from the vapor phase with solid phase microextraction (SPME). Qualitative and quantitative determination by gas chromatography with mass spectrometry (GC-MS) followed. The results of measurements of all methods were compared with the validation procedure using statistical methods. From the chromatograms and the results of the analytical methods, we can conclude that we have successfully introduced and optimized the test method - SPME GC-MS. We proved the linearity, accuracy and precision of the analytical method, and we also determined the LOD and LOQ. We can also confirm the selectivity and specificity of the test method, as we successfully separated chromatographic peaks for each analyzed component. With the optimization of the test method, we significantly shortened the time of sample preparation and analysis, as the samples do not need to be distilled beforehand.
Secondary keywords: beer;fermentation byproducts;validation;optimization;gas chromatography;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: XII, 58 str.
ID: 13117692