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The influence of thermal treatment on life of particular food products.
Žůrková, Pavla ; Ing.Gabriela Dereňová (referee) ; Ing.Petr Koflak (advisor)
This work deals with influence of heat processing on longevity of two selected products of the packing company Seliko trading a.s. For the research there were selected products Sterilised sauerkraut in sweet-sour pickle and Fatback spread. Evaluation has been done in laboratory premises of the packing company. There has been monitored mikrobiological stability after heat processing and sensory properties of the mentioned products always with an interval of one month. During the monitored seven months there appeared changes in taste and consistence of the products that are not defective in these products. The microbiological test taken after seven months was negative, just like at the beginning of the experiment. The result of the given findings is that the heat sterilisation was efficient and that during the storage there did not rise number of micro-organisms in the products.
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Microbiology of raw milk and milk after treatment
Pláničková, Jana ; Vítová, Eva (referee) ; Omelková, Jiřina (advisor)
The aim of this bachelor thesis is microbiology of raw milk and heat treatment milk, pasteurized and UHT treatment. There are described the most important and the most common microorganisms that contaminate milk, spoilage and pathogenic in the theoretical part. Practical part was provided in laboratory of diary factory. There were determined counts of microorganisms in raw, pasteurized and UHT milk by microbiological analysis.
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Importance and utilization of cellulases
Stuchlíková, Olga ; Babák, Libor (referee) ; Omelková, Jiřina (advisor)
The theoretical part of my bachelor thesis focuses on studying plant cells and polysaccharides, from which the cell wall is made of. The main attention is held on cellulose. Secondly, cellulases and microorganisms, which produce these enzymes, are mentioned. This work also deals with the actual use of cellulases in industry and agriculture. The last chapter of the theoretical part is devoted to immobilization, immobilized enzymes and their use in practice. The practical part of my bachelor thesis focuses on determination of basic properties of commercially used enzyme Celluclast 1.5 L. The temperature and pH optimum and temperature and pH stability were determined experimentally. The attention is also held on immobilization of these cellulases on synthetically prepared carrier „Sorsilen“. Subsequently, basic characteristics were determined as well as for soluble form of commercial enzyme.
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Conservation of corn silage
KŠANDA, Martin
This bachelor thesis deals with using of maize for production of silage that has a high potential and that are an irreplaceable part of a cattle nutrition. The introductory part focuses on the origin, characteristics and description of individual parts of plants. This chapter is followed by a mention of the posibilities and use of silage hybrids of maize. Following chapter describes the procedure of conservation and fermentation. The thesis also mentions microorganisms that have a positive as well as negative influence on the whole procedure. An interesting chapter is an introduction ofa silage additives. The conclusion is about constructions that are used for silage. One of the most important parts of a thesis is a technological description of the procedure of silage, together with harvest methods and factors, which are of great importance for a final product- a good quality and eneregy- rich feed, that a corn silage undoubtedly is.
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Monitoring of thermophilic organism in evaporation systems
VÁLKOVÁ, Michaela
Study deals with the determination of thermophilic and heat-resistant microorganisms in samples of skim milk. Furthermore, the problems of determining the thermophilic microorganisms in samples of whey. The most important microorganisms causing spoilage of milk and dairy products include certain species of the genera Bacillus and Clostridium. Thermophilic microorganisms have optimum growth temperature between 55 and 60 ° C. Removed material (skimmed milk and whey) was plated onto agar GTK and cultured in an incubator for 3 days at 55 ° C. Heat resistant microorganisms are characterized by resistance to heat. Prior to inoculation was necessary to inactivate other microorganisms by pasteurizing milk (85 ° C, 10 minutes). The inoculated Petri's dishes were cultured for 3 days at 55 ° C. Analysing removed material, it was found that the number of thermophilic micro-organisms in samples of skim milk does not exceed an internal limit the value of 3000 colonies per 1 ml or a gram of product (value determined Southbohemian dairy Madeta a.s.). The number of heat-resistant microorganisms has not exceeded the limit value of 2000 micro-organisms per 1 milliliter or gram. The resulting numbers of thermophilic microorganisms in samples of whey were almost identical to the results provided by Madeta a.s. factory Plana nad Luznici. The results show that after the introduction of new sanitary measures numbers of thermophilic and heat-resistant microorganisms fell sharply.
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Reducing of microorganisms in meat products - effect of storage temperature
ZÁHOROVÁ, Jana
In this thesis I deal with the influence of storage temperature on reducing the number of microorganisms in meat products. In this work is analyzed cooling and freezing storage of meat and meat products. The next section provides an overview of the major contributors to food-borne illness (Salmonella, Escherichia coli, Campylobacter, Listeria monocytogenes, Bacillus cereus, etc.). At the end of research is the mention of the HACCP system. The research was focused on the refrigerated storage of whole (rod) sausages and vacuum packed sliced meat products, which were further divided into cooked and uncooked meat products. The thesis was evaluated the effect of changes in temperature and storage technology to the number of microorganisms in cooked and uncooked meat products.
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The influence of packaging on the microbiological status of meat.
KOURKOVÁ, Dita
This thesis examines the influence of packaging on the microbial condition of beef for sale. The beef - Muscullus semimembranosus - was studied in an unpackaged state, and in the packaging of stretchable plastic wrap, in multilayer polyamide - polyethylene (PA / PE) wrap using a protective atmosphere and using 80% of vacuum into a bag from a multi-layered PA / PE wrap. The beef was stored at refrigerated temperature of +5 ° C. The total number of microorganisms (the number of colony forming units) were examined for 27 days. The compared samples show that the speed of increasing number of microorganisms is dependent on the type of packaging. According to the observed averages the best results are showed at meat packaged into a modified atmosphere and vacuum packaging, where there were no significant differences between these two types. Statistically there were no sigificant differences between the observed types of packaging. Packing in plastic wrap reduced microbial contamination of meat compared to unpackaged meat, but with vacuum packaging and modified atmosphere it could not be compared.
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Effect of packaging technology for shelf-life products
RYKROVÁ, Lucie
Microbiological quality of food is important both because of hygiene and health and has a significant influence on the shelf life of foods. The aim of this thesis was to evaluate samples of meat products for contamination by microorganisms. There was soft meat product, the product heat-processed and heat-treated. Evaluated how they affect the product and then cutting up into the vacuum packaging the total number of microorganisms, the influence of ambient temperature on the development of bacteria and the production have been using the new technology will benefit the health quality of the product. As revealed from the results, a product bar showed fewer organisms than product, which was sliced and then packaged in a vacuum. The fault was apparently slicing equipment that was not completely disinfected, and there was a transfer of bacteria. Therefore, it is necessary to improve sanitation and to see to their strict compliance. Resulting in the effect of temperature on the growth of microorganisms. The rising temperature is increased, the number of microorganisms. Use of air-conditioned chambers in the production of meat products is shown in terms of reducing the total number of microorganisms as a positive.
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Microorganism Reduction Methods in Meat Products
ZÁHOROVÁ, Jana
In Bachelor thesis I deal with a theme of the influences on the reduction of microorganisms of meat products. First, I focused on the characteristics of individual organisms, the factors affecting their growth, incidence of microorganisms in meat, forms of microbial degradation and contamination of meat microorganisms in slaughterhouses. The next section deals with the means to fight against microorganisms and methods which can reduce their presence in meat products. In the end there is mention of the HACCP system.
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Culture Collection of Soil Actinomycetes in the Institute of Soil Biology BC ASCR, v.v.i. České Budějovice
Krištůfek, Václav ; Chroňáková, Alica ; Elhottová, Dana ; Petrásek, Jiří ; Němec, Jan
The Culture Collection of Actinomycetes in České Budějovice (CCACB) was established in 2006 that serves as a depository for cultures of soil actinomycetes. The cultures can be used for research, industrial applications, education and general scientific interest. Cultures are preserved mainly in glycerol or freeze-dried conserves. CCACB will offer strains of actinomycetes, namely streptomycetes (more than 900 cultures at the present moment), in catalogue of cultures www.upb.cas.cz, www.actinomycetes.cz.
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