DINAMIKA NASTAJANJA VIŠJIH ALKOHOLOV IN ESTROV V FERMENTIRANIH PIJAČAH IZ JEČMENOVEGA, KVINOJINEGA IN AJDOVEGA SLADU

Brečko, Natalija

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Title:	DINAMIKA NASTAJANJA VIŠJIH ALKOHOLOV IN ESTROV V FERMENTIRANIH PIJAČAH IZ JEČMENOVEGA, KVINOJINEGA IN AJDOVEGA SLADU
Authors:	ID Brečko, Natalija (Author) ID Kolar, Mitja (Mentor) More about this mentor... ID Brodnjak-Vončina, Darinka (Comentor) ID Košir, Iztok Jože (Comentor)
Files:	UNI_Brecko_Natalija_2014.pdf (3,70 MB) MD5: BEB79C9F56D58F32DBAE3BF42772BC72
Language:	Slovenian
Work type:	Undergraduate thesis
Typology:	2.11 - Undergraduate Thesis
Organization:	FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:	Namen diplomskega dela je bila uvedba in validacija analizne metode za določanje višjih alkoholov in estrov v pivu in pivu podobnih pijačah v odvisnosti od surovine in zaporednega števila fermentacij. Omenjene spojine v pivu nastajajo kot stranski produkti med procesom fermentacije in prispevajo predvsem k aromi piva tako v pozitivnem kot v negativnem smislu. Pomembnejši alkoholi v pivu, ki smo jih določali so: metanol, 1-propanol, izobutanol (IUPAC nomenklatura: 2-metilpropan-1-ol), 2-metilbutanol, 3-metilbutanol ter 2-feniletanol. Pomembnejši analizirani estri so bili: etil acetat, izoamil acetat ter 2-feniletil acetat. Ti tvorijo tradicionalni nabor pomembnejših hlapnih spojin, ki se tudi najpogosteje spremljajo v pivu. Poleg tega smo poskušali določiti tudi: vicinalna diketona 2,3-butandion (diacetil) in 2,3-pentandion ter aldehida acetaldehid in trans-2-nonenal, ki so prav tako pomembni predstavniki arome piva. Namen raziskave je bil validirati omenjeno metodo in ugotoviti ali je primerna za določanje vicinalnih diketonov in aldehida, primerjati vsebnosti zgoraj omenjenih hlapnih spojin v pivinah in pivu iz različnih surovin (ječmen, ajda, kvinoja) ter preučiti vpliv večkratne zaporedne uporabe kvasovke pri fermentaciji. Kot metodo za določevanje smo uporabili plinsko kromatografijo destilata piva. Rezultati nakazujejo, da tako surovina kot zaporedna fermentacija vplivata na končne koncentracije hlapnih snovi, kot tudi na potek njihovega nastanka med fermentacijo. Razlike pri ajdi v primerjavi z ječmenom niso tako velike, da bi močno vplivale na kvaliteto končnega produkta, pri kvinoji pa so odstopanja od tipičnega ječmenovega piva relativno velike, zato praktično ne more služiti kot brezglutenski nadomestek običajnega piva. Kvasovka, ki smo jo pri vseh eksperimentih uporabljali (S. pastorianus TUM 34/70) se je z vidika hlapnih spojin izkazala kot primerna za zaporedno fermentacijo ječmenove, ajdove in kvinojine pivine.
Keywords:	pivo, plinska kromatografija, alkoholi, estri, validacija, gluten
Place of publishing:	Maribor
Publisher:	[N. Brečko]
Year of publishing:	2014
PID:	20.500.12556/DKUM-43796
UDC:	543.544.3:663.476(043.2)
COBISS.SI-ID:	17853718
NUK URN:	URN:SI:UM:DK:PYHZDOT7
Publication date in DKUM:	28.03.2014
Views:	2856
Downloads:	236
Metadata:
Categories:	KTFMB - FKKT
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Secondary language

Language:	English
Title:	THE DYNAMICS OF HIGHER ALCOHOL AND ESTER FORMATION IN FERMENTED BEVERAGES FROM BARLEY, QUINOA AND BUCKWHEAT MALT
Abstract:	The purpose of this diploma work was to introduce and validate the analytical method for the determination of higher alcohols and esters in beer and gluten-free beer-like beverages as a function of raw material and successive fermentation. Higher alcohols and esters are mainly by-products of the fermentation process and contribute to the beer flavour both in positive and negative sense. Some important higher alcohols, we tried to determine, were: methanol, 1-propanol, isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol), 2-methylbutanol, 3-methylbutanol and 2-phenylethanol. Similarly, some important esters like ethyl acetate, isoamyl acetate and 2-phenylethyl acetate were determined. All these compounds, together with acetaldehyde, form the common set of volatile compounds which are regularly observed during beer analysis. In addition, we also tried to determine two vicinal diketones, i.e. 2,3-butanedione (diacetyl) and 2,3-pentanedione and one aldehyde trans-2-nonenal, which are also important representatives of beer aroma. Therefore, besides the validation of the method our intention was also to find out whether it is suitable for the determination of above-mentioned vicinal diketones and aldehyde. Finally, the method was used to follow the content of all the above-mentioned volatile compounds in wort and beer from different raw materials (barley, buckwheat, quinoa) and each of them fermented successively for eleven times. Gas chromatography of the beer distillate was used as the method for determination. The results showed that both the raw material and successive fermentation influence the final concentration of volatile substances, as well as the profile of their production during fermentation. For buckwheat, differences in regard to barley were not so great that they would essentially affect the quality of the final product. On the other hand, the quinoa beverage deviates from a typical barley beer substantially and for this reason it can not be used as a gluten-free substitute for barley beer. Yeast, which was used in all experiments (S. pastorianus TUM 34/70) was in terms of volatile compounds proved to be suitable for sequential fermentation of barley, buckwheat and quinoa wort.
Keywords:	beer, gas chromatography, alcohols, esters, validation, gluten

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