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Influence of production environment on the occurrence of contaminating Penicillium in smear ripened cheese
Veselá, Vendula ; Brázda, Václav (referee) ; Vítová, Eva (advisor)
The topic of this thesis is the monitoring of the environment in a cheese production plant specializing in cheese ripened under a smear rind. The aim is to evaluate the occurrence of Penicillium mold as the main contaminant microorganism, depending on the sampling location and production time. Air samples were collected throughout the production process using the sedimentation method at 21 designated locations. The total number of microorganisms, selected groups of microorganisms, and the target microorganism (Penicillium mold) were monitored in the collected samples using cultivation (according to ČSN standards), microscopic, and molecular diagnostic techniques. The aim was to evaluate the occurrence of Penicillium citrinum, chrysogenum and commune species in dependence on the sampling location and production time. As part of the production screening, the broader microflora was first evaluated, followed by monitoring for contaminating molds. Using macroscopic and microscopic methods, 36 morphologically distinct colonies were selected. Microscopic analysis confirmed the presence of bacteria, yeasts and molds of the genera Penicillium, Cladosporium and Aspergillus. In order to identify the microorganisms present, an analysis using the polymerase chain reaction (PCR) method was performed, preceded by DNA isolation using the NucleoSpin Microbial DNA kit and phenol extraction. Based on real-time PCR results, the occurrence of contaminating Penicillium and Cladosporium molds was detected even in the early stages of production. Molds from these genera are found throughout the entire facility except for the single room that serves as a curd cooler before forming. Aspergillus mold, in the form of yellow mold with white mycelium on the edge of the colony, was detected only once in the drying room where cheese ripening occurs, and confirmed by microscopic observation. The genus Cladosporium was found in five morphologically distinct forms in the production environment. In addition, DNA was isolated from 11 morphologically distinct bacteria. Real-time PCR identified this DNA as belonging to coryneforms, with four of them belonging to the genus Brevibacterium. The genus Penicillium was represented by 13 morphologically distinct colonies, real-time PCR confirmed the presence of Penicillium commune and Penicillium chrysogenum. In addition to the mentioned molds, 11 morphologically distinct bacteria were detected, from which DNA was isolated. Real-time PCR identified this DNA as belonging to coryneforms, with 4 of them belonging to the genus Brevibacterium. The results of this work completely map the contamination of the production environment of the plant, and based on these results, methods for environmental sanitation were proposed to ensure the decontamination of the production process.
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Production of acid- vs. rennet-curd fresh cheese varieties
Veselá, Vendula ; Suská, Alžběta (referee) ; Vítová, Eva (advisor)
This bachelor thesis‘ focus is on the production and characterization of fresh cheese. Model samples of fresh cheese were produced on VUT Brno using purely acidic curdling (cream cheese culture – lactic acid), combined curdling (cream cheese culture + rennet) and acidic combined with heat curdling (acetic acid. 92 C) The samples were observed for their content of bound and free fatty acids, volatile (aromatic) substances and for their sensory quality. The goal was to determine the influence of the method of curdling on the observed factors. The fats were extracted from the samples using a mixture of diethyl ether and petroleum ether solvents. The fatty acids were esterified with acid to methyl esters under boron trifluoride catalysis and identified by the GC-FID method. In the cheese curdled by combined curdling, a greater amount of free fatty acids was detected compared to the other samples. No significant difference in the amount of bound fatty acids was observed. The greatest fatty acid content overall was observed in the cheese produced by acidic curdling. For identification and semi-quantification of the volatile (aromatic) substances, an HS-SPME-GC-MS method was used. 72 volatile compounds were identified in the samples. The percentual representation of different chemical groups varied significantly, the highest number of volatile substances was observed in the cheese produced by acidic curdling. Sensory evaluation was conducted using an evaluation scale as well as a ranking test. In all the observed indicators, the commercial sample was evaluated the best. The cheese produced by combined curdling was received rather negatively due to the sour taste. The second-best cheese was ranked to be the cheese produced by acidic curdling. The results show that the acidic curdling is the best for taste as well as aromatic substance and fatty acid content. If we, however, consider other factors such as the time taken, the cheese produced by combined curdling appears to be the best overall.
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Production of acid- vs. rennet-curd fresh cheese varieties
Veselá, Vendula ; Suská, Alžběta (referee) ; Vítová, Eva (advisor)
This bachelor thesis‘ focus is on the production and characterization of fresh cheese. Model samples of fresh cheese were produced on VUT Brno using purely acidic curdling (cream cheese culture – lactic acid), combined curdling (cream cheese culture + rennet) and acidic combined with heat curdling (acetic acid. 92 C) The samples were observed for their content of bound and free fatty acids, volatile (aromatic) substances and for their sensory quality. The goal was to determine the influence of the method of curdling on the observed factors. The fats were extracted from the samples using a mixture of diethyl ether and petroleum ether solvents. The fatty acids were esterified with acid to methyl esters under boron trifluoride catalysis and identified by the GC-FID method. In the cheese curdled by combined curdling, a greater amount of free fatty acids was detected compared to the other samples. No significant difference in the amount of bound fatty acids was observed. The greatest fatty acid content overall was observed in the cheese produced by acidic curdling. For identification and semi-quantification of the volatile (aromatic) substances, an HS-SPME-GC-MS method was used. 72 volatile compounds were identified in the samples. The percentual representation of different chemical groups varied significantly, the highest number of volatile substances was observed in the cheese produced by acidic curdling. Sensory evaluation was conducted using an evaluation scale as well as a ranking test. In all the observed indicators, the commercial sample was evaluated the best. The cheese produced by combined curdling was received rather negatively due to the sour taste. The second-best cheese was ranked to be the cheese produced by acidic curdling. The results show that the acidic curdling is the best for taste as well as aromatic substance and fatty acid content. If we, however, consider other factors such as the time taken, the cheese produced by combined curdling appears to be the best overall.
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The colour symbolics in marketing communication as applied to campaign for general election in June 2006
Veselá, Vendula ; Dolanský, Pavel (advisor) ; Hubálek, Slavomil (referee)
The bachelor's thesis concentrates on defining colour influence on the political parties' campaign for 2006 general election in the Czech Republic. We considered only fi ve major parties - The Czec h Social Democratic Party, The Christian and Democratic Union. Czechoslovak People' s Party, The Communist Party of Bohemia and Moravia, The Civic Democratic Party and The Green Party. The opening part of this thesis deals with the history of colour context, colour associations and psychic influence on man. In the theoretical part it is suggested which marketing tools does the political communication use and then the thesis has a detailed look on advertisement with a handsight of colour. The main stress is put on the political poster, important part of the political mass communication. We also studied the web presentations, which has become part of the campaigns and have more and more inn uence on the voters. The last chapter dea ls with the political spectrumand steady colour associations. Colour can be very influential means of communication. which is easy to remember. It also has other benefits, as it has psychological infl uence on a person, thanks to our own experience with the colour. These experiences have often common features. which make the communication easier. The political parties discussed chose...
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