|
|
Characterization of goat milk
Pospíchalová, Alžběta ; Burdějová, Lenka (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the sensory evaluation of goat milk. The differences in the sensory properties of goat and cow milk samples were followed. In the theoretical part goat milk is characterized, its composition, physical and chemical properties as well as its sensory properties are described. After that the methods of sensory evaluation are described. In the experimental part three samples were subjected to sensory evaluation, two samples of goat milk and one sample of cow milk, by the untrained assessors, which means common consumers. The observed properties, evaluated using a seven-point scale, were appearance, colour, texture, odour, flavour, off-flavour and the overall acceptability of samples. The results were graphically and statistically processed. The sample of cow milk was evaluated as the best; the acceptability of goat milk was negatively influenced by bitterish taste with the goat off-flavour.
|
|
|
Bioactive substances for face cream: Determination of stability of face cream incorporated with goat's milk
Dostálová, Tereza ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
The aim of this bachelor thesis is a stability trial of a skin cream incorporated with goat milk lyophilizates prepared in usual laboratory conditions. Firstly, the goat milk was denatured, to be further analysed via FTIR, elemental analysis and thermogravimetry. To compare the denaturation effect, measurements with native goat milk sample were performed as well. Next, an emulsion was prepared. First stability tests were performed using analytical centrifuge and the cream preparation procedure and component ratio was optimized. Stability trials were carried out at specified time intervals. Rheological properties – especially yield stress values and structure strength, determined by linear viscoelastic region and complex modulus – thermal endurance measured via differential scanning calorimetry and visual validation via optical microscopy and sample observation were tested and performed. Skin cream stability of sample stored at laboratory temperature was demonstrated, showing moderate sings of structure destabilisation. Product suitability for dry skin was proved by sensory analysis. The skin feeling was pleasant, and the cream moisturized the surface area, that it was applied to, according to evaluators. Visually, the emulsion appeared to maintain its properties during the experiment time range, it did not undergo a complete degradation of separation into two original phases, nor it was degraded, for example by mold.
|
|
|
Faktory ovlivňující počet somatických buněk v kozím mléce
Kocourková, Lenka
The aim of my bachelor thesis is to describe the factors influencing the number of so-matic cells in goat milk. The first part is devoted to the history of goat breeding in the world and the Czech Republic. Some important breeds of dairy goats are described here, including their brief characteristics and also the development of the numbers of the animals kept. The second part describes and evaluates the basic indicators of milk, which are used as indicators used to predict the quality of milk, especially the content of protein, lactose, milk fat, degree of acidity (SH), pH and electrical conduc-tivity of milk. The number of somatic cells in milk is largely influenced by external and internal factors such as breed, nutrition, lactation, health, breeding technology and milking technology and hygiene. This indicator is so significant that it becomes one of the main criteria for assessing the quality of raw milk. Therefore, the last part of the thesis is devoted to the evaluation of the causes of the increase in the number of so-matic cells in milk in relation to external and internal factors and especially in relation to physiology and diseases of the mammary gland.
|
|
|
Hodnocení jakostních parametrů kozích jogurtů v závislosti na vstupní surovině
Němcová, Vendula
The aim of the work was to evaluate the physico-chemical and microbiological parameters of organic goat yoghurts and milk, which was used for their production. The results were evaluated depending on the season and storage time of yoghurts. Sampling took place during spring, summer, autumn and winter. The sampling schedule during storage was chosen according to the shelf life given by the producer with the possibility of extending the shelf life of the product. The evaluated parameters included dry matter, fat, protein and lactose content, titratable and active acidity and microbiological analysis (total number of microorganisms, lactic acid bacteria, psychrotrophic microorganisms, coliform bacteria, enterococci and micromycetes). Goat's milk and, depending on it, yoghurts were subject to seasonal changes in composition with a higher dry matter content in winter and lower in summer. These differences were also reflected in the different titratable acidity and the total number of microorganisms. No coliform bacteria were present in the yoghurts. Enterococci, psychrotrophs and micromycetes (mostly yeasts) have been reported. Between the 3rd and 13th day of storage the number of psychrotrophs and micromycetes increased significantly. For yeasts and molds, another significant increase followed between the 18th and 24th day of storage. Only slight post-acidification was observed during yoghurt’s storage.
|
|
| |
|
| |
|
|
Bioactive substances for face cream: Determination of stability of face cream incorporated with goat's milk
Dostálová, Tereza ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
The aim of this bachelor thesis is a stability trial of a skin cream incorporated with goat milk lyophilizates prepared in usual laboratory conditions. Firstly, the goat milk was denatured, to be further analysed via FTIR, elemental analysis and thermogravimetry. To compare the denaturation effect, measurements with native goat milk sample were performed as well. Next, an emulsion was prepared. First stability tests were performed using analytical centrifuge and the cream preparation procedure and component ratio was optimized. Stability trials were carried out at specified time intervals. Rheological properties – especially yield stress values and structure strength, determined by linear viscoelastic region and complex modulus – thermal endurance measured via differential scanning calorimetry and visual validation via optical microscopy and sample observation were tested and performed. Skin cream stability of sample stored at laboratory temperature was demonstrated, showing moderate sings of structure destabilisation. Product suitability for dry skin was proved by sensory analysis. The skin feeling was pleasant, and the cream moisturized the surface area, that it was applied to, according to evaluators. Visually, the emulsion appeared to maintain its properties during the experiment time range, it did not undergo a complete degradation of separation into two original phases, nor it was degraded, for example by mold.
|
|
|
Význam selénu vo výžive kôz
Bieleschová, Ela
The theoretical part of the master's thesis contains knowledge about nutrition of goat, anatomy of the digestive tract, free radicals, selenium and ingredients of goat's milk based on available literature resources. The objective of the practical part was to experimentally determine the impact of the the addition of selenium to feeding ration for organic raised goats on qualitative and quantitative parameters of goat's milk and selenium content in goat's milk. The experiment was held on an organic farm in Prostejov area in June and July 2016, it lasted 30 days. Goat breeds raised on the farm were White Shorthaired and Anglo-Nubian. There were 12 goats studied in the experiment, divided into a treatment group (n = 6) and a control group (n = 6). Milk samples from each goat were collected at the beginning and end of the experiment The samples were analyzed in a laboratory for analysis of milk in Brno - Turany, selenium was analyzed at the Department of Chemistry and Biochemistry MENDELU. The results were evaluated and compared. The results of the experiment shows that the addition of selenium had an impact on its concentration in goat's milk but it had no effect on milk components (fat, protein, lactose, urea, somatic cell count) and milk yield.
|
|
|
Složení kolostra a mléka ve vztahu k biochemickému profilu krve u koz
Korbélyiová, Lenka
The main topic of this thesis was to study changes of goat colostrum and milk during lactation and the context of their composition and biochemical parameters of goat blood. The literature review summarizes the basic information about goat milk, its production, factors which determine its quality and how nutrition affects the composition of goat's milk. The practical part of this work is devoted to the evaluation of the goat colostrum and milk composition and its comparison to the lactation phase and to the biochemical tests of the blood of these animals. For the purpose of this study, 15 white shorthair dairy goats were monitored for 30 days, colostrum and milk samples were collected nine times and blood was collected three times for biochemical profile evaluation. Fat, protein, lactose, fat free solids, somatic cell counts and electrical conductivity were determined in colostrum and milk samples. These results were compared and found similar with the values from other studies and a similar progress of lactation was observed. Furthermore, the correlation coefficients between colostrum / milk parameters and the values of biochemical examination of goat blood were calculated. The results of interrelationships of blood biochemical parameters and colostrum / milk composition do not confirm the unequivocal relationship between biochemical blood parameters and colostrum / milk composition. Given the large number of factors that may affect both colostrum and milk composition and the concentration of biochemical parameters of blood plasma, further research focused on the relationship between these indicators in dairy goats would be appropriate.
|
|
|
Produkce a složení kozího mléka
Baďurová, Tamara
In my bachelor thesis, firstly I focused on the importance of goat breeding and reasons why we breed goats. In a few sentences I processed what diferences are between cow milk and goat milk in their quality and composition. The biggest part of my bachelor thesis include factors which influence quality of milk. Quality of milk is related to compositions of milk and milk yield. I focused especially on factors which influence content of fat, protein, lactose, mineral substances, vitamins, microorganisms, somatic cell and residues of the inhibitory substances. In the second part I focused on factors which influence milk yield of goats. Among these factors belongs lactation stage, order of lactation, time and rightness of milking, frequency of milking, pregnancy stage, number of born babies, weather, stress factors, udder size, body framework, live weight, nutrition, breeding method, hormones, breed, individuality, lokomotion, rut cycle, age and health condition. In conclusion in a few sentences I devised how and when take the control sample of goat milk, how to determine the milk yield and laboratory let to determine selected compositions of milk such as fat, protein, lactose, somatic cell and microorganisms.
|
guest ::
