Povećanje koloidne stabilnosti piva

master's thesis

• Title (english): Improvement of colloidal stability of beer
• Author: Ana Peroš
• Mentor: Božidar Šantek (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2012-11-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Poznato je nekoliko metoda za povećanje koloidne stabilnosti piva. Prva metoda je uklanjanje proteina koji su prekursori stvaranja mutnoće,a druga mogućnost je uklanjanje polifenola. Svrha ovog istraživanja je bila pronaći sto prirodniji način za smanjenje mutnoće piva uz korištenje vrsta hmelja koje su bogate na polifenolima. Pretpostavka je bila da će visoka koncentracija polifenola omogućiti bržu reakciju s prisutnim proteinima. Stvoreni kompleks se može ukloniti procesom filtracije. Visoka koncentracija polifenola utječe i na antioksidativni potencijal piva. Proveden je dekokcijski način ukomljavanja, a proces vrenja je proveden u cilindrično-konusnim fermentorima tijekom 46 dana. U eksperimentu su korištena tri različita tipa hmelja. Dobiveni rezultati su pokazali da pivo proizvedeno s ekstraktom hmelja i peletima T45 ima najveći udio polifenola te najveći antioksidativni kapacitet. Proizvedeno pivo je imalo i finu punoću okusa.

Abstract (english)

There are several methods for improvement of colloidal stability of beer. The first method is sorption removal of protein haze precursor, and the second sorption removal of polyphenols. Purpose of this study was to find out a more natural way to reduce beer haze by using specific types of raw hop materials rich in polyphenols. It was assumed that high concentration of polyphenols in beer will allow faster reaction with haze active proteins. The formed haze can be removed by filtration. Higher concentration of polyphenols in beer brings the very high antioxidant potential. Brewing process was carried out with three different combinations of hop preparates. Mashing process was performed by decoction process and obtained hopped wort was inoculated with layer yeast strain. Fermentation was carried out in cylindrical fermentors during 46 days. Obtained results show that beer prepared with hop extract and hop pellets T45 has highest total polyphenol content and antioxidant capacity as well as enchanting beer flavor.

• Keywords: hmelj; koloidna stabilnost; polifenoli; antioksidansi
• Keywords (english): hop; colloidal stability; polyphenols; antioxidant capacity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:635748
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-08 10:34:20