Utjecaj parametara okoline na proces glavnog i naknadnog vrenja sladovine s povećanom koncentracijom ekstrakta

master's thesis

• Title (english): The effect of wort fermentation conditions on the conduction of fermentation and maceration with an increased concentration of extracts
• Author: Monika Mihoci
• 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: 2010-07-05, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

U ovom istraživanju proučavan je utjecaj promjena parametara okoline na proces glavnog i naknadnog vrenja piva u industrijskim cilindrično konusnim fermentorima (3600 hL). Tijekom glavnog i naknadnog vrenja piva osim glavnih proizvoda vrenja (etanol i CO2) nastaju i drugi nusproizvodi vrenja koji imaju značajan utjecaj na aromu i okus piva. Tlak i temperatura u CKF – u te koncentracija i aktivnost stanica kvasca su najznačajniji parametri koji određuju brzinu glavnog i naknadnog vrenja [npr. sinteza i razgradnja vicinalnih diketona (VDK)]. Rezultati ovih istraživanja pokazuju da promjene tlaka u rasponu od 0,5 bara kao i promjene brojčane koncentracije stanica kvasca u rasponu do 15 x 106 stanica mL-1 nemaju značajniji utjecaj na okus i aromu gotovog piva. Na osnovi rezultata ovog istraživanja formirana je ovisnost između promjene pH vrijednosti i koncentracije VDK koja se može koristiti za procjenu koncentracije VDK tijekom glavnog i naknadnog vrenja piva.

Abstract (english)

In this investigation the effect of wort fermentation conditions on the conduction of fermentation and maceration of beer in industrial cylindro – conical fermentor (CCF; 3600hL) was studied. Main wort fermentation products are ethanol and CO2 but except them other fermentation by products are also obtained that have significant impact on the beer taste and aroma. Pressure and temperatur in CCF and initial yeast cell number have the highest impact on the rate of wort fermentation as well as on the rate of vicinal diketones synthesis and degradation. Results of this research clearly show that the changes of fermentation pressure in the range of 0,5 bars as well as initial yeast cell number in the range of 15 x 106 cell mL-1 did not have significant impact on the beer taste and aroma. On the basis of these results correlation between pH value and vicinal diketones concentration was formed that could be used for evaluation of vicinal diketones during beer fermentation and maceration.

• Keywords: pivo; glavno i naknadno vrenje; cilindrično konusni fermentor; kvasac; vicinalni diketoni; ugljični dioksid
• Keywords (english): beer; fermentation and maceration; cylindro – conical fermenters; yeast; vicinal diketones; carbon dioxide
• Language: croatian
• URN:NBN: urn:nbn:hr:159:365568
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-08-24 07:40:45