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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.
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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.
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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.
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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.
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Clotting of cow and goat milk
PECOVÁ, Lenka
The thesis deals with two technological properties determining the quality of milk, clotting and fermentation ability by titrable acidity, which are influenced by a large number of factors. The aim of the work was to assess the influence of milk composition, breed, order and stages of lactation on clotting and souring ability of cow and goat milk based on obtained analysis. Detailed analysis focused primarily on cow milk.
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Vyhodnocení úrovně mléčné užitkovosti v chovu koz na farmě Bílsko
MAJTÁNOVÁ, Lenka
The aim of the thesis is to evaluate milk production levels of goats on the ecological farm Bílsko. The thesis analysed selected factors influencing goat milk production, especially the quality and quantity of feed and the age composition of herds. In order to assess the milk production, a data set from the primary breeding records from 2012 to 2016 was used. The milk production on the farm increased at that time. The milk production reached 417 kg in 2012 and then 437 kg in 2013, 555 kg in 2014, 633 kg in 2015 and 648 kg in 2016. The thesis also evaluates the content of milk constituents, that is fat, protein and lactose. In 2012 the milk consisted of 3.88% fat, 13% protein and 4.4% lactose. In 2013 it contained 3.29% fat, 3.23% protein and 4.4% lactose. In 2014 the milk contained 3.26% fat, 3.17% protein and 4.4% lactose. In 2015 the fat content decreased to 2.79% and the protein content decreased to 2.98% while lactose reached 4.5%. In 2016 the fat content again decreased to 2.53% and the protein content decreased to 2.83% while lactose increased to 4.71%. The milk production results in the selected herd were compared with national data. Based on the obtained data, the conclusion provides measures that would increase the milk production. These include mainly reducing the number of goats, removing old goats from breeding and improving feed rations.
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Vyhodnocení mléčné užitkovosti vybraného chovu koz
KRAPKOVÁ, Adéla
The aim of this diploma thesis is to asses the effect of various factors on the milk production and its content in regard to goat's milk in the years 2015 to 2017. The evaluation was conducted on goat farm Richmond Stars in Chotětov. The farm currently accommodates 31 goats of the white shorthaired breed. They are still opting for the one rectangular space solution. The feeds consist of bulk fodder, silage, hay and grass (pasture during summer). The feed composure is the same throughout the whole year. The water supply system consists of water containers with manual refill. The goats are divided into groups based on their age. Milking takes place twice a day. The data on milk production was processed using Microsoft Excel and Statistica. When comparing the overall milk productivity with the average of Czech Republic, there were statistically significant differences found in the fat content in the year 2016, in the protein content in years 2015, 2016 and 2017, in the lactose content in the year 2015. In all cases, the Richmond Stars farm was the one with better score. Other results were evaluated as inconclusive and therefore no statistically significant difference was found. When considering the impact of the goat's age on the milk productivity and the goat's milk content, there was a statistically conclusive impact in the productivity (milking) itself as well as in the fat content. When observing the impact of the father-line on the productivity level and the milk content, there was a statistically conclusive result only in the fat content. When evaluating the impact of the period of birth on the milk productivity and milk content, there was a statistically conclusive impact on the fat and lactose content. All other results, specifically the productivity (milking), were evaluated as inconclusive and therefore were not statistically significant for the purpose of evaluation of the milk productivity characteristics.
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Fatty acid composition of caprine milk and milk products
PECOVÁ, Lenka
Changes occur in milk during the technological processing of raw milk, which also affect the properties of milk fat. Dairy products may have different properties compared to the raw milk. Chemical and microbial processes can alter the presence and distribution of individual fatty acids and thus influence the nutritional value of the product. The aim of this thesis was to assess the presence of fatty acids in milk fat of goat milk and to evaluate differences in the spectrum of fatty acids in goat milk and yoghurt produced from it.
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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.
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Quality indicators of goat's milk
SAMOHEJLOVÁ, Kamila
The aim of this thesis was to evaluate the quality characteristics of goat milk on choice farm focusing on chemical composition, the assessment of changes during the year, explaining the causes of the differences, where the design procedures to improve the current situation. The quality indicators of the work focused primarily on the content of fat, protein, lactose and milk yield. Sampling was performed in 6 control periods (May - October) during 2009 from 14 goats included in performance tests. The average milk yield in the herd was found 4.48 kilograms. The average percentage of fat was found to 4,15%, protein 3.18% and 4.52% lactose. Found in fat and protein exceed those appearing in the breed standard. Effect of stage of lactation was confirmed (p <0.001) in all monitored parameters.
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