Fiziološka aktivnost odgorčenog kvasca Saccharomyces uvarum nakon ultrazvučne dezintegracije

master's thesis

• Title (english): Physiologycal viability of debittered yeast Saccharomyces uvarum after ultrasound disintegration
• Author: Ana Raukar
• 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: 2008-12-22, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Pivski kvasac Saccharomyces uvarum odgorčavan je dodatkom Tweena 80 pri različitim pH vrijednostima suspenzije i reakcijskim vremenima. Nakon odgorčavanja je istraživan utjecaj niskofrekventnog ultrazvuka (20 kHz) na fiziološku aktivnost odgorčenog pivskog kvasca tijekom tretmana od 1-10 minuta, pri snazi od 50 % (trajnoj ili pulsirajućoj u intervalima od 10 sekundi). Morfološke promjene u stanici kvasca, prouzročene različitim ultrazvučnim tretmanima, pH vrijednostima suspenzije kvasca i reakcijskom vremenu, praćene su mikroskopski, nakon čega je agregacija kvaščevih stanica kvantificirana. Dobiveni rezultati pokazali su da je vrijeme izloženosti ultrazvuku, posebno pulsirajućoj dezintegraciji, povećala broj oštećenih stanica, što je rezultiralo povećanjem nakupina stanica (aglomerata). Fiziološka aktivnost odgorčenih stanica ispitivana je određivanjem broja mrtvih stanica, te udjela glikogena i volutina.

Abstract (english)

Brewer’s yeast Saccharomyces uvarum was debittered with Tween 80 at different pH values and reaction times. The physiologycal viability of brewer’s yeast (Saccharomyces uvarum) cell suspensions as a function of treatment time (1-10 min) was investigated during exposure to both standing (50 % power) and pulsing (10 sec pulsation intervals) low frequency ultrasound wave fields (20 kHz) at suspension pH value of 9.5. Changes in yeast cell morphology caused by the different mode of ultrasound treatment, pH value of yeast suspensions, and treatment time were observed by light microscopy and recorded onto a PC. Aggregation of brewer’s yeast cells has been monitored and quantified. The obtained results show that exposure time and pulsing wave treatment obviously increased the degree of damaged cells and resulted in broadening the agglomerate size. 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): debittering; brewer's yeast; physiological activity; Saccharomyces uvarum; Tween 80
• Language: croatian
• URN:NBN: urn:nbn:hr:159:731967
• 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: 2017-08-31 10:49:52