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Metody hodnocení a zkoušení medu s důrazem na jeho jakost a pravost
Kučerová, Tereza
This bachelor thesis is concerned with the methodology of honey evaluation and testing. It characterises the different components contained in honey and its properties. The thesis deals with the determination of these parameters and presents methods for their determination. It describes mainly the chemical and physical analysis, which includes sensory analysis, determination of water content, determination of sugars, sucrose content by polarization, 13C/12C isotope ratio, hydroxymethylfurfural (HMF), antioxidant content of electrical conductivity, thiric acidity and pH. The last part includes microscopic analysis and characterization of microorganisms in honey.
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Hodnocení jakosti a autentičnosti ovocných šťáv
Dufková, Petra
The literary part of the bachelor´s thesis comprises of material composition, the technology of production and forging of fruit juices. The research in this thesis is dealing with the analysis of 3 different kinds of fruit juice (apple, orange and grapefruit) purchased in a retail network. There have been evaluated 19 samples in total, in which density, soluble dry basis, titratable acids, malic acid, citric acid and ascorbic acid were determined. As samples were used fruit juices purchased in a retail network which were produced by pressing or from a concentrate or from fresh fruit. Obtained results were compiled to a table, compared with allowed values from the AIJN codex and evaluated.
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Authenticity of food on the Czech market
LÍBALOVÁ, Renata
The Thesis acquaints consumers with Czech and European legislation regarding food quality and safety. There are also described in detail the supervisory autorities for food authenticity operating in Czech Republic and related terms such as food quality and safety. The following is a pivotal part dedicated to the food authenticity, which describes the problem of food adulteration, including the reasons and methods of food adulteration. The practical part contains the results of inspections of food by SZPI for the year 2015. The analysis of the data is based on the website "Potraviny na pranýři". Another part relates to the evaluation of questionnaire, which focuses on consumers's relationship to authenticity and adulteration of food on the Czech market. The practical part is concludes by the evaluation of set hypotheses.
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Hodnocení barvy medu
Černá, Eva
The aim of the thesis on "Evaluation of the color of honey" was to determine why the instrument can not Lovibond Honey Colorpod 440110 to evaluate color of all types of honey and compare results of with spectrophotometric measurement methods. The work is divided into theoretical and practical part. The theoretical part is dedicated to honey, its composition and methods of evaluating color. The practical part describes the results obtained instrument Lovibond Honey Colorpod -- 440110, spectrophotometers Konica Minolta -- 3500d a FT -- NIR Antaris. In UV/VIS region not been demonstrated reason of errors of photometer. Maximum lightness had a very light honeys and the largest share of yellow had light honey. The highest values of absorbance attain dark honeys. In color space CIE L* a* b* had the largest share of red. Evaluation of the color of honey in the UV/VIS can not prove adulteration of honey always unambiguously, but there are signs by which honey can be described as suspicious. By analyzing the NIR spectrum is falsification of honey demonstrated using discriminant analysis.
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The control of Toma orange juice authenticity on the basis of selected chemical properties
Cvrková, Jana ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
This study verifies Toma orange juice authenticity on the basis of selected chemical properties. In the theoretical part are definitions of the basic concepts concerning the orange juice. This part is also focused on characterization of technology procedures of orange juices, historical development of legislation in the European Union and Czech Republic, the most frequent ways of adulteration of fruit juices and methods, which determine their authenticity. In experimental part were made determinate analyses of orange juice Toma and experimental results were compared with standard values. On this basis it was deduced a conclusion about authenticity of orange juice Toma from commercial network.
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The control of Tesco orange juice authenticity on the basis of selected chemical properties
Belková, Renáta ; Šalplachta, Jan (referee) ; Hrstka, Miroslav (advisor)
This study deals with verifying the Tesco orange juice authenticity, on the basis of selected chemical parameters. In the theoretical part there is orange juice defined according to actual standards, described its production and the legislation in EU and in the Czech Republic. There are next mentioned the basic practices of adulteration of orange juice and possibilities of its detection and some analytical methods for verifying the orange juice authenticity. In the experimental part of the study there was the authenticity of the sample of orange juice Tesco from the trade network tested with some standard analytical methods. Regarding to the results of the analysis, which were within the limits of the standard values, the conclusion can be written that analysed sample of the orange juice was authentic.
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Využití NIR spektroskopie při kontrole falšování kozího mléka
Ptáčková, Eva
The aim of the thesis was to find out whether NIR spectroscopy is a suitable method for adulteration control of cow and goat milk. Also to which concentration level the method is still effective was sought. Theoretical part summarizes information about the requirements for goat milk, its composition and processing possibilities. It also contains information about food adulteration and the relevant legislation. Infrared spectroscopy is theoretically described, particularly NIR spectroscopy. The experimental part describes the procedure of qualitative analysis using NIR spectroscopy, the method of evaluation and its results. Different samples of goat milk adulterated with various proportions of cow milk were compared. Results were evaluated using discriminant analysis. NIR spectroscopy has been demonstrated as a method suitable for detecting goat milk adulteration.
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Využití NIR spektroskopie při kontrole falšování kozích sýrů
Přikrylová, Iveta
Diploma thesis deals with use of near-infrared spectroscopy to detect falsification of goat's cheese. The basic knowledge of goat's and cow's milk and requirements for milk during cheese production are summarized in the theoretical part. There is also described the cheese production and the following part is devoted to food falsification with describing falsification of milk products and the facilities of adulteration detection by optical methods. The remaining part deals with NIR spectroscopy as a suitable method for the verification of food authenticity. The practical part is focused on the use of NIR spectroscopy to detect the difference between cheese samples with different concentrations of cow's milk in goat's cheese and subsequent use of discriminant analysis for evaluation. The results showed that the method is suitable for detection of falsification of goat's cheese and that is why could be useful for rapid analysis in practice.
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Med - jeho původ a označování v tržní síti
Bakrlíková, Veronika
The bachelor thesis deals with the origin of honey and different ways of labeling types of honey and even some of its falsification. The work is divided into several parts: a brief description of the basic concepts and definitions of honey, evaluation, origin and labeling of honey, as well as the preparation of honey on sale and customer requirements. In the results of the thesis discusses the shortcomings of the existing legislation in determining the types of honey and the importance of labeling for consumer informations. My work also includes examples of the most common defects of the control of the State Agricultural and Food Inspection Authority. In conclusion, I try to suggest possible solutions for to specify the labeling of honey on the label for uniformity and accuracy of information.
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