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Mléčný tuk a jeho využití v potravinářských technologiích
Nejedlíková, Martina
This bachelor thesis deals with milk fat and its use in dairy technology. The composition of milk is summarized and the knowledge regarding milk fat, its structure and properties is presented in details. Part of the thesis is devoted to methods of treatment and fractionation of milk fat. The findings regarding the studies of the antibacterial activity of lactose monolaurate ester (LML) and lactose monodecanoate (LMD) in milk at different temperatures and fat contents are summarized. Furthermore, the research trend of using milk fat in 3D food printing is presented, which offers new opportunities in the field of food design and customization. Overall, milk fat has significant applications in dairy technology and research trends in its use provide exciting opportunities for the development of the food industry.
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Vliv úrovně metabolických procesů živočišného organismu na zastoupení lipidových složek mléka
Šulová, Marie
This bachelor thesis entitled ‘Influence of the level of metabolic processes of animal organism on the representation of lipid components in milk’ deals with physiological processes which influence synthesis, composition and release of lipids by secretory cells of the mammary gland through various metabolic ways. The introductory chapter focuses on the characteristics of the basic components in milk; individual fractions of milk fat are described in detail. The following chapters describe the synthesis of milk fat and lipid metabolism in the body of ruminants, namely cattle, and factors that influence the amount and composition of milk fat. A proposal of the methodology of experimental work describing division of animals into groups, feed diets and the overall progress of the experiment is a part of the thesis.
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The effect of polymorphism of some enzymes on fatty acid composition in cow´s milk fat
SVOBODOVÁ, Martina
The aim of the diploma thesis was to determine the genotypes of polymorphic variants of some candidate loci in the AGPAT6 and LEP genes and to evaluate the influence of these polymorphic variants on milk yield and milk fatty acid proportions. Genotypic and allele frequencies of AGPAT6 and LEP were determined in dairy cows (n = 400) of the Czech Fleckvieh breed and its crossbreeds. The PCR / RFLP genotyping method was used. The results showed that the CT (AGPAT6) and MM (LEP) genotypes predominated in the population. The influence of AGPAT6 and LEP polymorphisms on milk yield indicators for the 1st and 2nd lactation could not be demonstrated. The influence of the AGPAT6 genotype on the representation of some short-chain fatty acids has been demonstrated. The effect of the LEP genotype on fatty acid proportions has not been demonstrated. The results of this work make it possible to obtain a more favorable composition of milk fat with respect to human health.
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The level of energy metabolism of dairy cows and the composition of milk fat
KAUTSKÁ, Jitka
The aim of this study was to evaluate the relationship between the levels of energy metabolizm of high-yielding dairy cows and the amount of milk fat. Furthermore, the proportion and content of fatty acids in milk fat. The effect of antiketogenic prophylaxis of the monenzin-containing preparation was also evaluated, and the metabolic parameters were evaluated at the same time. The experiment took place in the breeding of high-yield dairy cows of the Holstein breed in the company Agropodnik Košetice a.s. s The average milk yield in breeding was 11,553 kg of milk in the observed period. The highest acid content was recorded in the first month of lactation and their content gradually decreased. Likewise, they had the highest proportion of short-chain saturated fatty acids (SAFA). The application of monenzin has a proven incidence of subclinical ketoses, both in first-calves and in cows for second and subsequent lactation. The reduction of ß- hydroxybutyric acid in blood and milk confirms the importance of the antiketogenic prophylaxis used.
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Vliv výživy na mléčné složky u dojnic
Zmrhal, Vladimír
The individual components of milk are differently influenced by nutrition. Milk fat is the most impressionable component of milk. Its content is largely influenced by structure feeding ration and the amount of fibre in ration, acetic acid originates in which the fermentation as the main precursor of milk fat. Fat composition can be also influenced by feeding fats protected against degradation in the rumen and linseed or rapeseed seed which act to the content of unsaturated fatty acids. Negative effect on milk fat has mainly higher content of starch in feeding ration. Milk proteins are influenced by the amount of microbial protein synthetized in the rumen which is influenced by the ratio of degradable protein and energy feed. On the content of milk proteins act also so-called by-pass protein and nondegradable amino acids. Especially methionine and lysine, which are considered as limiting for the synthesis of milk proteins. The content of lactose is reduced when the organism is in the energy deficit and also by influence of mastitis. The aim of this work is to describe the mechanism by which nutrition act on dairy components.
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Změny ve složení a technologických vlastnostech kravského mléka v průběhu dojení
Vávrová, Růžena
The aim of this thesis was to analyze changes in the composition and technological properties of cow's milk during the milking. Part of the work was practical research on the farm and subsequent analyzes of milk samples obtained from four cows. Samples were taken during milking using a special cane that allowed the milk to be divided into four fractions. The 1st fraction was obtained at the beginning of milking, 2nd and 3rd during and 4th fraction at the end of milking. Average values of samples of milk were as follows: 1.72 kg quantity of milk, fat content 4.1 %, protein content 3.09 %, lactose 4.62 %, non-fat dry matter 8.41 %, ash 0.69 %, density 28.51 kg/l, 1.11 % water, the freezing point of -0.538 °C, rennet coagulation time 136.59 sec and 1.47 the quality of the curd. From the results of this research, I can say that the influence of the individual milk fraction has greatly influenced its quantity, fat content, density, water percentage and milk freezing point. For other monitored components, the effect was inconclusive. The individuality of the cow has a significant influence on the quantity of milk. The fact that the milk was obtained in summer or winter significantly affected fat, protein, lactose, non-fat dry matter, ash, density, water percentage and milk freezing point. The remaining monitored parameters have been implicitly affected.
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Variabilita složení mléka na farmě
Žitňanová, Natálie
This bachelor thesis focuses on the distribution of milk by its stage of lactation, that is immature milk or colostrum and mature milk. There is distribution by protein type as well. Thesis is focused on dairy cow milk, describing its individual components such as milk fat, proteins, lactose, minerals enzymes and states signs of quality grade of raw milk – physical and chemical properties and means of quality assurance, means of milk production, varieties of milking and types of milking parlors – tandem, her-ringbone, parallel or rotaional. Thesis also describes milk after milking process, inclu-ding purification, filtration, cooling and storage, sanitation of milk technology and its resources and execution. Thesis deals with microclimate and genetics effect, physiolo-gical and illness influence on milk and its individual components as well.
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Výroba a druhy másla
Skopalová, Eva
Butter is a dairy product that contains 80-90% milk fat, a maximum of 16% water and 2% non-fat ingredients, including proteins, saccharides and fat-soluble vitamins. Butter can be produced in three different ways - concentration, emulsification and churning. In the Czech Republic is mainly used the method of churning. The concentration and emulsification process is used for production in the USA. There are many kinds of butters on the market in the Czech republic. The main ones include fresh and table butter. The defects of butter that arise during the production and storage of the butter can be taste and aromatic or consistent. Buttermilk is a by-product of butter production. Buttermilk can be further processed as an additive to a variety of dairy products. Due to its composition and low fat content (0.5%) we rank it among healthy foods.
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Analýza vybraných jakostních parametrů mléka u dvou plemen skotu v průběhu roku
Životská, Hana
This diploma thesis is focused on the analysis of selected quality parameters of milk from two breeds of dairy cattle during a year. The literary review contains the information about the basic structure of cow's milk and with a more detailed focus on ingredients, which were observed in this thesis (proteins, fat, lactose, chlorides and somatic cells). In addition, the information was also included on basic milk quality indicators and the information about breeds of dairy cattle from which came samples of milk. Samples for analysis came from dairy cows of Czech Fleckvieh breed (farm GenAgro Ricany, a.s.) and from dairy cows of Holstein breed (University farm Zabcice). Samples of milk were obtained during 4 seasons, namely from January 6th 2017 to December 7th 2017. Analysis of variance (ANOVA) showed that the content of the milk observed components is influenced besides else factors, also by the season (in the winter protein content achieved values on averaged 3,31 % and 3,19 % in the summer). Moreover, a significant negative correlation coefficient was detected between proteins and somatic cell count (r = -0,73) and between lactose and somatic cell count (r = -0,45). Overall results showed that all milk samples meet the quality limits (proteins ≥ 2,8 %, fat ≥ 3,3 %, SCC ≤ 400 103.ml-1).
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Reologické vlastnosti různě tučných bílých jogurtů
Synková, Lucie
This diploma thesis Rheological properties of plain yoghurts with various fat content is aimed in its theoretical part on the basic summary of fermented milk products. It is focused mainly on yoghurts, especially plain yoghurts. The manufacture, composition, nutritional and health benefits, storage and shelf-life of yogurts is described. In the next chapter are described rheological properties of foods. The aim of the practical part is to assess rheological properties of plain yoghurt with various fat content. All samples are commonly available in the Czech shops. The range of fat content was 0,1–10,2 g/100 g. The dependency of shear stress on shear rate was studied as well as the dependency of apparent viscosity on shear rate (1,02–68 s-1). The rheological properties were fitted to Ostwald-de Waele model (the Power law). It was assessed that yoghurt is a Non-Newtonian fluid with shear thinning behaviour. Determination coefficients achieved high values (0,8748–0,9905). Time dependency and effect of various temperature (4 °C, 12 °C and 22 °C) on apparent viscosity was assessed. pH, titrable acidity, fat content and dry matter content were observed for all samples.
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