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Effect of Camellia sp. on dairy matrix digestion
Scholzová, Tereza ; Potůčková, Miroslava (advisor) ; Vladimír, Vladimír (referee)
The aim of this bachelor thesis is to summarise of current knowledge about the effects and biological properties of the substances contained in leaves of Camellia sinensis, their digestion and their effect on the digestion of dairy matrices. Camellia sinensis is a plant, which is used to tea production. Tea is manufactured by fermentation of tea leaves and according to its degree it is possible to prepare different kinds of this product. The best known are green, black and oolong tea. Beverages prepared from tea leaves contain many bioactive compounds, including alkaloids, free amino acids, proteins and vitamins. However, the most important are polyphenolic substances flavonoids, which are also the major bioactive constituents of tea. These compounds have many pharmacological properties such as antiatherosclerotic, antibacterial, anticancer, antiviral, hypolipidemic and hypocholesterolemic.
The effect of milk on the biological activity of tea polyphenols has been a subject of many studies but the mechanism by which the antioxidant activity of this compounds affect milk and dairy products and especially their digestion process has not been fully understood yet. It was found that flavonoids can interact with proteins rich in prolin, including also casein, via covalent and noncovalent interactions, especially by hydrophobic interactions and hydrogen bonds. The resulting complexes may destabilize protein molecules and cause their precipitation, thereby their digestibility is improved. On the contrary, stable complexes protect polyphenols from autooxidation. Interesting is also crosslinking effect of green tea flavonoids on milk proteins. These substances also have the ability to form complexes with lipids and lipolytic enzymes and so decrease lipids digestion and absorption, including the milk fat and its accompanying components such as cholesterol. It was also observed reduced absorption of other fat-soluble substances like persistent organic compounds.
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Caseinomacropeptide biological properties
Vašíčková, Klára ; Potůčková, Miroslava (advisor) ; Michaela, Michaela (referee)
The aim of the bacherol thesis was to summarize the current knowledge about biological properties of caseinomacropeptide. Caseinomacropeptide is hydrophilic, mostly glycosylated peptide which commes from kappa-casein during its chymosine proteolysis.
Polypeptide has a lot of interesting functional and biological properties thanks which has a wide potential for food industry and development of new products with added value. Its valuable physico-chemical properties include surface activity (emulsifying and foaming properties), gel-forming and adsorption properties, thermo- and acidobasic stability. From the biological effects may be mentioned antibacterial, anticariogenic, antiviral, dietary, effects on the gastrointestinal tract, hypoallergenic and immunomodulatory properties and prebiotic.
In many studies was observed that the higher biological activity of caseinomacropeptide (native or hydrolysed forms) is connected with its glycosylation. One of the most important parameters is also sialic acid content. Good bioactive properties also demonstrated polypeptide conjugates with galactooligosaccharides. Antibacterial effect of caseinomacropeptide was recorded for example against pathogenic strains of Escherichia coli ETEC K88, Salmonella enterica subsp. enterica serotyp typhimurium CECT 443 a Listeria monocytogenes CECT 935. Polypeptide acted as prebioticum for Bifidobacterium animalis subsp. lactis BB12, Bifidobacterium bifidum CCDM 94, Bifidobacterium thermophilum RB 267, Lactobacillus bulgaricus ATCC 7517, Lactococcus lactis subsp. Lacti and Lactobacillus rhamnosus RW-959-M. Anticariogenic properties of caseinomacropeptide were successfully used against selected strains of Streptococcus mutans, sanguis and sorbinus and model hydroxyapatite system. Glycosylated forms of polypeptide also stimulated gastric and pancreatic enzymes and cholecystokinin secretion but any positive influence of caseinomacropeptide on appetite and hunger suppressing and food and energy intake decreasing has not been observed.
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Složení a vlastnosti ovčího mléka a jeho využití v mlékárenství
Nováková, Vendula
This bachelor thesis provides information on composition and properties of sheep's milk and deals with impacts affecting its composition and properties. Individual components and selected properties of sheep's milk are compared with those of cow's milk. The thesis also focuses on nutritional aspects of sheep's milk and its products. In the final part of the thesis I describe the most popular products from sheep's milk, including mostly cheese, for the production of which is the sheep's milk the most suitable option, and I describe other products characterized by high nutritional value and positive effect on human organism.
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Porovnání metod měření syřitelnosti mléka
Valíčková, Jana
This Master thesis called Comparison of methods for measuring milk coagulation deals with a major technological step in the production of cheese, which is the process of curdling of milk. Two methods for measuring this process were compared, particularly the visual and instrumental method utilizing nephelo-turbidimeter. Based on statistical data processing in three cases, a difference was observered between the average visual measurement and instrumental measurement of significant 99%. Furthermore, the impacts on curdling of milk were assessed what showed that the best default property for the process of curdling had a pasteurized milk sample with the addition of CaCl2. On the basis of calculations in this thesis it has been concluded that to curdle a 100 l of milk with rennet CHY-MAX a 0,2 liters of the rennet is required. The same amount of milk is curdled with 1 litre of rennet Lactochym. In assessing the economics of using rennet Lactochym and CHY-MAX it has been found that for cost optimization it is more appropriate to use rennet CHY-MAX with a strentgh of at least 190 IMCU/ml diluted in distilled water at a ratio of 1:5.
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Cheese curd parameters influence to selected economic factors of production of cheese with white fungus
Pavlíčková, Žaneta ; Zemanová, Jana (referee) ; Babák, Libor (advisor)
The theme of this diploma thesis is the monitoring of influences on economic aspect of the production of the blue cheese "Hermelín" in the company Pribina. The objective was to specify the dependencies of the deviations of the features of productive cow's milk and of cheese curd made from it and their economics impacts. For this purpose, the analyses of curd grain, whey and cheeses just formed were executed. The samples were taken and analyzed during the manufacturing of cheeses in the factory. Another goal was to try to design a quick operational method for measuring the firmness of curd grain, which is a factor theoretically dependent on renneting qualities of milk and indicating losses of valuable components from cheese curd to whey. The firmness of grain along with these losses may cause negative deviations from required standard of final products, especially at parametres needed for entry of cheeses on sale, such as total solids, weight or content of fat. Concerning productive pasteurize milk, the most attention was focused on the milk coagulation time and its influence on successive phases of manufacturing and on final product. Milk coagulation time is an essential technological quality of milk and it is participant on quantitative and qualitative production of cheese factory. It has been proved that milk coagulation time is notably affected by its titrating acidity, statistic analyse found this influence as very statistically significant (P
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