20.500.12556/RUL-161403 Vpliv pripravka Aromazyme na biotransformacijo aromatičnih spojin iz hmelja med fermentacijo piva Effect of Aromazyme addition on the biotransformation of aromatic compounds from hops during beer fermentation Namen magistrske naloge je bil preučiti vpliv pripravka Aromazyme na sproščanje in biotransformacijo aromatičnih spojin iz hmelja v pivo, pri tem smo se osredotočali na monoterpenske alkohole. V praktičnem delu smo naredili 3 fermentacijske poskuse, kjer smo uporabili 2 seva kvasovk in 2 obliki hmeljev ter spremljali različne parametre. Pri prvem fermentacijskem poskusu smo z merjenjem fluorescence opazovali razliko v beta-glukozidazni aktivnosti ob dodatku pripravka Aromazyme (koncentracije v pivu 5 g/hL in 10 g/hL) glede na na vzorec brez dodatka. Ugotovili smo, da ima večji dodatek pripravka večji pozitivni vpliv na beta-glukozidazno aktivnost, ki pa se je tekom fermentacije spreminjala. V drugem poskusu smo z vzorčenjem ob dodatku pripravka ter 2. in 4. dan od dodatka s pomočjo plinske kromatografije sklopljene z masno spektrometrijo (GC-MS) ovrednotili aromatični profil piva. Opazili smo nekoliko bolj izrazit negativen vpliv encimskega pripravka Aromazyme na vsebnost monoterpenskih alkoholov v primeru Kveik kvasovk in temperaturi fermentacije 30 °C. Pripravek je na pivo vplival večinoma negativno in povzročil padec vsebnosti aromatičnih spojin. Vpliv pripravka je bil odvisen tudi od kontaktnega časa, večji negativen vpliv je bil opažen pri daljšem času hladnega hmeljenja s CRYO obliko hmelja. Pri zadnjem fermentacijskem poskusu, namenjenem senzorični analizi, smo opazovali vpliv količine pripravka ob fermentaciji s Kveik kvasovkami in dodatkom CRYO hmeljev. Zaradi napake v izvedbi so bili rezultati neuporabni, kar smo potrdili s fizikalno-kemijsko analizo z napravo CDR BeerLab. V raziskavi nismo potrdili vseh hipotez, ovrgli smo tisti hipotezi, ki nakazujeta na pozitivne lastnosti uporabe pripravka v pivu. Smo pa v skladu s predvidevanji potrdili, da pripravek v pivu povzroči določene spremembe. The aim of the master's thesis was to study the effect of the Aromazyme preparation on the release and biotransformation of aromatic compounds from hops into beer, focusing on monoterpene alcohols. In the practical part, we conducted 3 fermentation experiments, where we used 2 strains of yeast and 2 forms of hops and monitored various parameters. In the first fermentation experiment, we observed the difference in beta-glucosidase activity by measuring fluorescence in samples with the addition of the Aromazyme preparation (concentration in beer 5 g/hL and 10 g/hL) relative to the sample without addition. We found that a higher addition of the preparation had a more significant positive effect on beta-glucosidase activity, which changed during fermentation. In the second experiment, we evaluated the aromatic profile of beer by sampling at the time of preparation addition and at 2, and 4 days after the addition, using gas chromatography coupled with mass spectrometry (GC-MS). We noticed a slightly stronger negative effect of the enzyme preparation on the content of monoterpene alcohols in the case of Kveik yeast and a fermentation temperature of 30°C. The preparation mostly had a negative impact on the beer, causing a decrease in the content of aromatic compounds. The effect of the preparation also depended on the contact time, with a greater negative impact observed with longer dry hopping times using the CRYO form of hops. In the final fermentation experiment, intended for sensory analysis, we observed the effect of the amount of preparation during fermentation with Kveik yeast and the addition of CRYO hops. Due to an error in execution, the results were unusable, which was confirmed by physico-chemical analysis with the CDR BeerLab device. We did not confirm all hypotheses in the study. We rejected those hypotheses suggesting positive properties of using the preparation in beer. Nevertheless, we confirmed our predictions that the addition of the preparation does cause certain changes in beer. pivo hmelj aromatične spojine beta-glukozidaza monoterpenski alkoholi Aromazyme beer hops aromatic compounds β-glucosidase monoterpene alcohols Aromazyme true false false [G. Korat] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2024-09-11 08:15:14 2024-09-11 08:15:24 2024-09-13 07:43:06 0000-00-00 00:00:00 2024 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 663.42+663.45:543.2/.9 244386 207375875 41083.pdf 41083.pdf 1 CE2B9573A2FE424C23EF56B67476FA54 91ffad535b8a499d51d99a759b3ff6eb92687671d4685c9ab0c8b7f29851e061 2d89a96f-7005-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=190332 Biotehniška fakulteta 0 0 0