Fiziološka aktivnost kvasca Saccharomyces uvarum nakon odgorčavanja s Tweenom 80

master's thesis

• Title (english): Physiologycal activity of yeast Saccharomyces uvarum after debittering with Tween 80
• Author: Andreja Đurinski
• 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: 2008-07-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Optimiranje uvjeta odgorčavanja biomase pivskog kvasca Saccharomyces uvarum provedeno je ispitivanjem utjecaja različitih volumnih koncentracija Tweena 80 (5; 10; 15 i 20 %), pH vrijednosti suspenzije (2 do 12), temperature (5 do 50 oC) i vremena reakcije (5 do 50 minuta). Odgorčavanjem s 20 % (vol/vol) Tweena 80, pri pH suspenzije 9,5, temperaturi od 50 oC i vremenu reakcije od 15 minuta, postignuto je smanjenje gorčine za 87 %, bez utjecaja na životnost kvasca i udjel proteina. Fiziološka aktivnost kvasca nakon odgorčavanja pokazala se iznimno dobrom, što je dokazano mikroskopski, mjerenjem udjela mrtvih stanica, glikogena i volutina, a nakon toga i pripravom kruha s odgorčenom biomasom pivskoga kvasca u različitim omjerima s biomasom pekarskog kvasca.

Abstract (english)

Optimization of conditions for maximal debittering of brewer’s yeast (Saccharomyces uvarum) was performed by adding different concentrations of Tween 80 (5; 10; 15; and 20 % v/v), adjusting pH values of suspensions from 2 to 12, varying temperature from 5 to 50 oC, and changing of reaction times between 5 and 50 minutes. The best results were achieved with bringing a brewer’s yeast suspension in contact with 20 % (v/v) of Tween 80, at pH 9.5, and agitating during 15 minutes at 50 oC. A bitterness reduction of 87 % was obtained without affecting yeast viability or protein content. Physiological activity of debittered yeast seems to be quite satisfactory, according to microbiological viability determinations (dead cells, glycogen and volutine content), and finally by baking bread with different ratios of debittered brewer’s yeast and commercial bakers yeast.

• Keywords: fiziološka aktivnost; odgorčavanje; pivski kvasac; Saccharomyces uvarum; Tween 80
• Keywords (english): physiological activity; debittering; brewer's yeast; Saccharomyces uvarum; Tween 80
• Language: croatian
• URN:NBN: urn:nbn:hr:159:096857
• 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: 2017-09-01 11:58:18