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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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Microbiology of raw milk and selected dairy products
BEZÁNYIOVÁ, Michaela
Milk is an important part of the human diet due to its composition. The aim of the bachelor thesis was to create a review focused on the microbiota of raw cow's milk and dairy products. The thesis summarizes the ways of primary and secondary microbial contamination of milk and describes the intrinsic and extrinsic factors influencing the growth of microorganisms. A particular attention is focused on mastitis, which are the main source of primary contamination of milk. The great emphasis is attended to the necessity of strict following of hygiene regulations during manipulation with this raw material. In the last part, potential health risks associated with consumption of milk and dairy products is mentioned. .
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The evaluation of milk quality in selected countries of European Union
POKORNÝ, Martin
The diploma thesis deals with the assessment of qualitative indicators of raw cow's milk supplies within the European Union (EU) and the Czech Republic (CR), de-pending on the year and course of the year. Within the EU average values for the observed period 2016-2020 were found for fat contents of 4.01 ? 0.26% and protein content of 3.39 ? 0.13%; in the CR 3.91 ? 0.11% and 3.46 ? 0.08%. The effect of the year within the EU countries was demonstrated only in terms of protein content (p <0.001). When evaluating the effect of individual months in EU countries, includ-ing the CR, statistically significant differences in fat (p <0.001) and protein (p <0.001) content were demonstrated. In summer, the values of both components in-creased, while in winter they decreased. The results of the evaluation of bulk milk samples purchased in the CR show, depending on the year, that the effect on the total bacteria count (p <0.001), residues of inhibitory substances (p <0.05) and freez-ing point of milk (p <0.001) was also found. The effect of the year was elicited for the total bacteria count (p <0.05) and the somatic cell count (p <0.001). From the point of view of milk sales, the quality of raw milk is a primary goal for the producer and at the same time a decisive factor in the monetization of this important animal commodity.
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Heat treatment of milk and its importance
VOČADLOVÁ, Kateřina
The aim of this work is to assess the public knowledge of heat treatment, its purpose and effect on milk quality and to find out their attitude to raw milk consumption. Heat treatment of milk is a commonly used part of dairy processing. Although the heat treatment has a significant impact on ensuring microbial quality, safety and shelf life of milk, its application still face a public disagreement, primary in connection with potential health benefits, which are lost during heat treatment. The survey took place (from November 2015 to February 2016) in a randomly selected group of respondents (n=265). It was found that 22 % of respondents buy raw (unpasteurized) milk and only 27 % of them reported pasteurizing of the milk before consumption. 68 % of respondents just cool the milk down and consume it without any thermal treatment. 23 % of respondents though that pasteurization has negative effects on milk quality and 21 % of respondents said that consumption of milk pose no health risk.
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Influence of cold chain interruption on microorganisms growth in milk
BEEROVÁ, Michaela
Raw milk is one of the most monitored product not only in terms of microbial, but also in terms of technology, chemistry and sensory. The aim of the thesis was the examination of the influence of cold chain interruptions on dynamic of total bacteria count (TBC) in raw cow milk. The results show that the temperature and time have a significant impact on TBC. The samples stored during the first three hours of experiment at 15 °C showed (in time 0 - 27 hours) a continuous growth with changing dynamic (5.13, 6.66, resp. log CFU/ml). The samples stored at 30 °C showed a significant increase, however there was a decrease between an hour of 25th and 26th (6.88, 6.69, resp. log CFU/ml). An hour later another increase was found (to 7.37 log CFU/ml). The samples stored at 6 °C showed the lowest values of TBC, although an increase was found after 24 hours (5.87 log CFU/ml). The second part of the thesis was an evaluation of the questionnaire survey among people consuming raw cow milk from a vending machine. The survey showed that more than a half of respondents (88%) interrupt the cold chain for no more than an hour. Then it was found that 75% of respondents do not overcook raw milk. The consumers appreciate the taste of raw milk (35%), freshness (19%), quality (16%), and a nutritional value (12%).
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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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Important food-borne pathogens in raw cow´s milk
HRUBEŠOVÁ, Kristýna
This work talks about the problems of food-borne pathogens in raw milk, with a special focus on Campylobacter jejuni and Staphylococcus aureus including its negative influence on health of the consumers. The topic of consumption of raw milk was lately a much discussed question and is further described in the text. With consideration to possible occurrence of food-borne pathogens, it is important to thermally treat raw milk before consumption. Despite this fact there is still a large number of consumers who don?t respect this technical procedure and they threaten their own health.
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Factors affecting quality of raw cow´s milk during milking and storage at farm
HAVRÁNKOVÁ, Iveta
Milk is one of the few products which we can use for direct consumption. Not only is it important for human nutrition as a raw product, but it also finds an increasing usage in food industry. The quality of milk is affected by various factors. This work deals only with the most important ones, which have an influence on the nutrition value as well as on the microbiological and hygienic quality of milk.
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