Knowledge base: Warsaw University of Technology

Back

Optymalizacja metody określania stopnia skażenia mikroorganizmami koncentratu soku jabłkowego

Katarzyna Filipek

Abstract

The most common cause of spoilage of pasteurized juices and fruit drinks are the bacteria Alicyclobacillus spp., especially species of Alicyclobacillus acidoterrestris. These acido-thermophilic, spore forming bacteria cause flat sour type spoilage related to the production of metabolites of unpleasant disinfectant odor. These compounds cause a significant reduction in the commercial value of the product, loss of confidence among consumers, and thus substantial economic losses. Therefore, development of a sensitive, highly selective and reproducible method for the detection and elimination of this microorganism is very important. The present study is focused on optimization of the method and determination of the optimum operating conditions for identification of microorganisms contamination of apple juice concentrate. In this study the lyophilized preparation EZ-FPC ™ Microorganisms (Microbiologics) containing vegetative forms of bacteria A. acidoterrestris ATCC 49025 on the concentration of 3.3 * 103 cfu per pellet (according to the manufacturer) was used. Analysis of the obtained results shows that the use of membrane filtration gave the best recovery of A. acidoterrestris bacterium. However, due to many drawbacks and limitations of this method in most cases it is recommended to use a surface plating. Among the four tested culture media, such as BAT, YSG, K and SK agar, the recovery of the test strain was the highest and the incubation time was the shortest in the case of YSG agar medium. Due to its characteristics, this medium is also conducive to the rapid production of spores. The most optimal incubation temperature conducive to bacterial growth on YSG agar was 46˚C. On the basis of the analyzed variants of the thermal shock was found that sufficient and optimal parameters is to use the heat shock temperature of 80˚C for 10 min
Record ID
WUT78f0cc11734d44e88157c47381ccd7de
Diploma type
Master of Science
Author
Katarzyna Filipek Katarzyna Filipek,, Undefined Affiliation
Supervisor
Marek Henczka (FCPE/DCRED) Marek Henczka,, Department of Chemical Reactor Engineering and Dynamics (FCPE/DCRED)Faculty of Chemical and Process Engineering (FCPE)
Certifying unit
Faculty of Chemistry (FC)
Affiliation unit
Department of Chemical Reactor Engineering and Dynamics (FCPE/DCRED)
Study subject / specialization
, Biotechnologia Przemysłowa
Language
(pl) Polish
Status
Finished
Defense Date
28-06-2012
Issue date (year)
2012
Keywords in Polish
-
Keywords in English
-
Abstract in Polish
urn:pw-repo:WUT78f0cc11734d44e88157c47381ccd7de