magistrsko delo
Nika Kunšek (Avtor), Helena Abramovič (Recenzent), Petra Terpinc (Mentor), Miha Ocvirk (Komentor)

Povzetek

V izvedbo magistrskega dela smo vključili 11 slovenskih sort hmelja in jih primerjali z znano nemško sorto Magnum. Iz hmeljnih briketov smo pri temperaturi 40 °C pripravili etanolne ekstrakte in jim določili vsebnost skupnih fenolnih spojin (SFS), skupnih flavonoidov (SF) in njihovih podskupin (flavonov in flavonolov (FF), flavanonov in dihidroflavonolov (FDH)) ter antioksidativni potencial (AOP). Zanimala nas je tudi korelacija med sorto hmelja in učinkovitostjo prehajanja SF, SFS, FF in FDH v pivo. V pivu smo določali še vsebnost alfa- in beta-kislin. Od slovenskih sort po vsebnosti SF, SFS in FF izstopa sorta Wolf. Več SF in SFS kot Magnum vsebujejo še sorte Fox, Aurora in Cardinal. Kolibri, Savinjski golding in Dragon so sorte z najmanjšo vsebnostjo SF in SFS. Najvišji AOP imajo sorte Dana, Gold in Aurora, medtem ko najnižji Savinjski golding. Daljši čas hladnega hmeljenja ugodno vpliva na večjo izluženost SF, SFS, FF in FDH v pivu, negativno pa na AOP piva. Največ SF so po sedmih dneh vsebovala piva hmeljena s sortami Wolf, Savinjski golding ali Bobek. Sorta Dana je po dodatku v pivo dala slabši rezultat kot Magnum. Po vsebnosti SFS in FF je izstopalo pivo s sorto Wolf. Največji prirast FDH smo potrdili pri pivu s sorto Aurora, najmanjši pri sorti Celeia. Pivu s sorto Dana smo določili enega najvišjih AOP. Najnižji AOP smo po sedmih dneh hmeljenja določili pivu z nemško sorto Magnum. Daljši čas hmeljenja je na večjo izluženost izo-alfa kislin vplival le pri štirih sortah: Wolf, Dragon, Aurora, Fox. Po enem dnevu hmeljenja smo največ kohumulona določili pivu s sorto Cardinal, največ n+adhumulona pivu s sorto Magnum, ksantohumola pa pivu s sorto Wolf; vsi trije parametri so s časom hmeljenja pri omenjenih sortah postopoma upadli.

Ključne besede

hmelj;Humulus lupulus L.;flavonoidi;fenolne spojine;antioksidativni potencial;alfa-kisline;beta-kisline;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.09 - Magistrsko delo
Organizacija: UL BF - Biotehniška fakulteta
Založnik: [N. Kunšek]
UDK: 633.791+663.423:547.56:577.1
COBISS: 114982915 Povezava se bo odprla v novem oknu
Št. ogledov: 101
Št. prenosov: 42
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Flavonoids in Slovenian hop varieties
Sekundarni povzetek: In our master's thesis, we included 11 Slovenian hop varieties and compared them with the known German variety Magnum. Ethanol extracts were prepared from hop briquettes at 40°C and the content of total phenolic compounds (SFS), total flavonoids (SF) and their subclasses (flavones and flavonols (FF), flavanones and dihydroflavonols (FDH)) and antioxidant potential were determined (AOP). We were also interested in the correlation between hop variety and the efficiency of transfer of SF, SFS, FF and FDH into the beer. The content of alpha- and beta- acids was also determined in the beer. Among the Slovenian varieties, the Wolf variety stands out in terms of the content of SF, SFS and FF. Fox, Aurora and Cardinal also contain more SF and SFS than Magnum. Kolibri, Savinjski golding and Dragon are the varieties with the lowest content of SF and SFS. Dana, Gold and Aurora have the highest AOP, while Savinjski golding has the lowest. A longer period of dry hopping has a positive effect on the higher content of SF, SFS, FF and FDH in the beer and a negative effect on the AOP of the beer. After seven days of hopping, beers with the varieties Wolf, Savinjski golding and Bobek contained the most SF, meanwhile variety Dana resulted in lower values than Magnum. In terms of SFS and FF content, beer made with Wolf stood out. The highest increase in FDH content was found in beer with the Aurora variety, and the lowest with the Celeia variety. We determined one of the highest AOPs for beer with the Dana variety. After seven days of hopping, the lowest AOP was determined for beer with the German variety Magnum. Longer hopping time influenced the higher transfer of iso-alpha acids only in 4 varieties (Wolf, Dragon, Aurora, Fox). The highest cohumulone in beer was determined after one day of hopping for Cardinal, the most n + adhumulone for Magnum and xanthohumol for Wolf; all three parameters gradually decreased with time of hopping.
Sekundarne ključne besede: hop;Humulus lupulus L.;flavonoids;phenolic compounds;antioxidative potential;alpha-acids;beta-acids;
Vrsta dela (COBISS): Magistrsko delo/naloga
Študijski program: 0
Konec prepovedi (OpenAIRE): 1970-01-01
Komentar na gradivo: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Strani: 1 spletni vir (1 datoteka PDF (XI, 58 str., [1] f. pril.))
ID: 15874306