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Determination of microorganisms in the air of food premises
Krýzová, Andrea ; Popelářová, Eva (advisor) ; Salmonová, Hana (referee)
Microorganisms are able to spoil foods with their presence in food plants, therefore,
there is necessary to perform the monitoring of microbial air quality. The aim of this Bachelor
thesis was to confirm that the air quality in the food plant is better than in the current
environment. Microbial cleanliness should be at the highest level, especially in places where
is risk of contamination of the products.
Air composition was observed in microbrewery by Czech University of Life Sciences
Prague. It was evaluated by the total number of microorganisms and number of moulds.
In the case of moulds there was also determined gender representation. Samples of air with
present microorganisms were collected from five parts of the brewery, using active air intake
with airsampler MAS 100 Eco (Merck, Germany). It was a sanitation station, lager beer cellar,
section wort cooling, boiling room and to compare the hall. Air analysis was performed twice
with intervals of two months.
According to the findings, in sanitation station can be found higher total number
of microorganisms than in the hall. However, this increased incidence could be related
to microbial penetration from the outside environment due to the use of makeshift door
leading into the room. In other parts of the operation has already been confirmed less than
the total number of microorganisms in the hall. Enumeration of molds revealed that the entire
operation were lower than the concentrations of these microbes in the corridor.
Dangerous place in the brewery in terms of contamination of the product is lager
cellar, because here with maturation occurs also his tapping. Here upheld a lower incidence
of microorganisms than in the current environment, and as other parts of the plant do not pose
a risk of product degradation, the objective has been achieved.
Of the native representation of mould in the air microbrewery it shows that the most
abundant mould genus was Cladosporium and Penicillium followed. Cladosporium occupied
on average 54,8 % of the total number of mould. At lower concentrations, there have been
also genera Alternaria and Aspergillus.
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Effect of Housing on the Content of Microorganisms in Cow's Milk
Červíková, Martina ; Popelářová, Eva (advisor) ; Pechar, Radko (referee)
This thesis focuses on the influence cow housing on the content of microorganisms in raw cow's milk. During the three months of spring and summer season in 2015 was performed in regular 14 - day's intervals of 6 milk sampling, always from two cows in large-capacity cow house and from two cows in family farm.
In all of the samples was determined the total quantity of microorganism, enterococcus and coliform bacterium in two settings.
Setting an overall quantity of microorganism gives the final quality of milk. The limit for fresh milk is, according to legislation, 100 000 KTJ/ml. This limit was not fulfilled by the first cow from the family farm in no case of all the settings. Overlimited CPM was found during the third setting by samples from family farm and large-capacity cow house by all of cows, too. In other cases of setting were samples suitable.
Setting enterococcus. For these days cancelled norm was setting the same amount as by the coliform bacterium, i.e. 1000 KTJ/ml. The limit fulfilled samples from large-capacity cow house as well as the private farm in 4 of 6 settings.
Setting a quantity of coliform bacterium points to faecal pollution. The norm
CSN 57 0529 stated the limit of 1000 KTJ/ml for coliform bacterium in raw milk; now it is not valid and was not replaced with new one. If it is still valid, this limit would be fulfilled in case of samples from private farm in 3 cases, in two others would cross the limit slightly and in the last setting the contamination is well over the limit.
The effect of cow housing was proved, there were differences between individual samplings from the same cow house. The lowest values reached the 4th sampling, the highest values reached 3rd and 6th sampling. This could be effected by weather and abnormal high temperatures.
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Microbiological control of dried fruit
Smolíková, Marie ; Popelářová, Eva (advisor) ; Šlapáková, Barbora (referee)
An important factor for assessing the quality of food is their microbial contamination. This Bachelor thesis deals with the microbiological quality of dried apples. Bachelor thesis is based on the assumption that the use of sulphites has influence of the content of microorganisms. The aim is therefore determine their number, the influence of use of sulphites on their content, eventually evaluate other effects of sulphites on dried apples.
Consuming food without additives is a trend of current time. If we are talking about dried fruit, additives are sulphites, which prevent primarily darkening of apples, they are used like preservatives, but they are allergen. So that is the reason why are Bio apples often coveted.
In the practical part were compared apples which were not sulphurized, apples which were sulphurized and Bio apples, which were made in Severofrukt a.s., Trávčice. It was used six samples of each type. In all samples were determinated total amount of microorganisms - CPM, amount of coliform bacterias, Escherichia coli, yeasts and molds. Assessment was performed on Petrifilms from NOACK Company. Samples were also sent to be compared to acredited labaratories. Next thing, which was done, was examination, if the use of sulphites has any other effects on dried apples.
All of samples fulfilled requirements of the Decree. In any of samples were not proven coliform bacteries or E.coli. According to analyzes Bio apples had the highest content of undesirable microorganisms. The total amount of microorganisms at them was in the average 11 000 KTJ/g. Sulphurized apples were less contamined than aplles, which were not sulphurized. The difference was almost about one half. This shows, that the use of sulphites has a positive influence on the content of microorganisms. And with the use of sensory evaluation was proved, that the use of sulphites has inluence on a colour of dried apples.
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Microbial contamination of fruit teas
Kuřáková, Hana ; Popelářová, Eva (advisor) ; Killer, Jiří (referee)
Teas are consumed daily by millions of people on the World, therefor it is important to care for their microbial harmlessness.
The aim of this work was to conduct a reaserch in regards to general information about fruit teas, their manufacturing and possibilities of contamination by undesirable microorganisms. In this research were also described important bacteria and fungii and we focused on mycotoxins and the elimination of microorganisms from a food.
Representation of microorganisms in teabags was evaluated in practical part of this research. We focused on total quantity of microorganisms, coliform bacteria, that can be pathogenic in higher representation and micromycetes. Genus structure of micromycetes was important in particular, because they can produce metabolites, mycotoxins, that can be a cause for many diseases.
Analyses were conducted by two methods. Variant classified as A was consisting of transformation of the teabag contents into the physiological solution. Variant classified as B was consisting of watering of the teabag contents. During evaluation, both of these variants were compared.
From the results of this work it was found out, that quantities of microorganisms were relativem small. It was discovered, that during the sample preparation by watering the sample with boiling water (variant B) the quantity of microorganisms will lower, in some cases they were not present at all. The presence of wider genera of micromycetes was also discovered. Three genera were dominant Aspergillus, Penicillum and Cladosporium. These free found of genera can be dangerous, because of mycotoxins, however micromytes in variant B were only represented by genera Cladosporium and Penicillum and in small measure.
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