Utjecaj ultrazvučne dezintegracije na agregaciju i učinkovitost autolize pivskog kvasca Saccharomyces uvarum

master's thesis

• Title (english): Effect of ultrasound desintegration on aggregation and brewer`s yeast (Saccharomyces uvarum) autolysis efficency
• Author: Lina Grubić
• Mentor: Sunčica Beluhan (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: 2005-12-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Procesom odgorčavanja otpadnog pivskog kvasca Saccharomyces uvarum, stupanj gorčine je smanjen za 76,49 %. Nakon toga su stanice kvasca, razbijane ultrazvučnom dezintegracijom pri čemu je razbijeno 77 % stanica. Naknadno je provedena autoliza uzoraka pri 80°C/24h (postotak mrtvih stanica je iznosio 98 %). U tako dobivenim uzorcima spektrofotometrijskom analizom su preliminarno određeni 5`- ribonukleotidi te proteini. Zatim su okusni 5`- ribonukleotidi (5`-GMP i 5`-IMP) detektirani tekućinskom kromatografijom visoke djelotvornosti (HPLC). Najbolji rezultati su dobiveni pri pH 8,5 i četvrte minute ultrazvučne dezintegracije. Uz izolaciju okusnih nukleotida u radu je prikazano svojstvo agregacije pivskog kvasca koje je najbolje izraženo pri pH 5,5.

Abstract (english)

After debittering process, the bitterness was diminished by 76.49 %.The brewer`s yeast cells, Saccharomyces uvarum, have been disrupted by ultrasound with efficiency of 77 %.The next step included autodigestion of the yeast, which was conducted by autolysis for 24 hours at 80 °C (with 98 % efficiency). Proteins and 5`- ribonukleotides were preliminary detected by spectrophotometric analysis. By using High Performance Liquid Cromatography (HPLC) flavor enhancers (5`-GMP i 5`-IMP) were detected. The best results were obtained at pH 8.5 and after four minutes of ultrasound disruption. This paper also shows aggregation of the yeast cells called flocculation being best at pH 5.5.

• Keywords: agregacija; HPLC; 5`-ribonukleotidi; pivski kvasac; Saccharomyces uvarum; ultrazvuk
• Keywords (english): aggregation; brewer's yeast; HPLC; 5`- ribonucleotides; Saccharomyces cerevisiae; ultrasound
• Language: croatian
• URN:NBN: urn:nbn:hr:159:497198
• 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: 2017-09-11 13:37:53