Fiziološka aktivnost kvasca Saccharomyces uvarum nakon optimizacije postupka odgorčavanja s Tweenom 80

undergraduate thesis

• Title (english): Physiologycal activity of yeast saccharomyces uvarum after debittering with Tween 80
• Author: Jelena Ratkaj
• 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: 2010-07-15, 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 (10 do 50 oC) i vremena reakcije (5 do 60 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.

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 10 to 50 oC, and changing of reaction times between 5 and 60 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).

• 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:159:845995
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-06-07 11:17:35