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Imobilizace galaktosidasy a její využití v potravinářské technologii
Dobešová, Natálie
This master‘s thesis deals with the issue of galactosidase immobilization and its use in food technology. β-galactosidase from Kluyveromyces lactis was immo-bilized using two methods, specifically encapsulation and cross-linking. The aim of the encapsulation was to obtain hydrogel capsules formed by a biopolymer matrix based on sodium alginate, crosslinked with calcium chloride for repeated catalytic use. The second chosen method was the enzyme cross-linking on a carrier formed by mag-netic particles modified with chitosan. Enzyme activity was determined spectropho-tometrically using the substrate o-nitrophenyl-β-D-galactopyranoside and p-nitrophenol as a standard. Enzyme activity was evaluated in milk samples and the amount of lactose formed was determined polarimetrically. The experimental results showed that the immobilized enzyme on the chitosan magnetic carrier showed higher activity compared to the sys-tem based on alginate capsules, which was also confirmed during the lactose hydroly-sis process. Lactose hydrolysis was the most efficient using a commercial enzyme and the enzyme immobilized on magnetic chitosan. There was no statically significant difference in the lactose content in milk samples without enzyme and with the use of alginate calcium capsules.
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Tisknutelné matrice na bázi složek mléka
Němec, Jan
The aim of the thesis is to introduce to the topic of 3D printing, milk components and their mutual connection. It explains individual technologies from the most common to the less well-known. Furthermore, the thesis deals with a review of current studies on this topic and their conclusions, progresses and complications. It focuses on individual components of milk, such as casein, micellar casein concentrate, milk protein concentrate, whey proteins and lactose, which have potential in 3D food printing. The thesis aims to provide a review of the information needed to understand 3D printing as it is used in other industries, as well as to understand the complexity of food 3D printing with a focus on milk. The main contribution of the work consists in providing comprehensible information and in the summarization of the indicated paths where 3D printing of milk has gone. Alternatively, it also reveals gaps that can be addressed and thus move development forward.
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Způsoby tepelného ošetření mléka a jeho dopady na nutriční jakost
Leischnerová, Zuzana
The topic of this bachelor thesis is "Ways of heat treatment of milk and its impacts on nutritional value". The theoretical part describes the composition of milk, its individual components and nutritional value. Other chapters focus on heat treatment, legislation concerning milk and differentiation of milk types based on intensity of treatment, individual treatments and their impact on the content and quality of individual components. At last there are described changes that occur in milk upon heating and reactions that may arise when exposed to high temperature. The nutritional value is generally lower than in raw milk, the changes are the most significant in sterilized milk, while the least change occur in the pasteurized milk. The practical part monitors the representation of individual types of milk on the market with respect to heat treatment and manufacturers. The questionnaire provides information from producers. The questionnaire shows that some manufacturers are already using ESL treatment in practice, but the term ESL is still not implemented in legislation.
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Sweeteners (natural and artificial) used in the food industry
PIHLÍK, Pavel
The aim of this work is to introduce the sweeteners which are used in the food industry in the Czech Republic but also in the world. The basic sweetener which is a measure of the other sweeteners is regarded as sugar (sucrose). In this bachelor´s work, I described the history of the production of beet sugar in the Czech Republic, the products which are made of it and also its usage in food industry. Furthermore, I introduce the basic types of sweeteners by which we try to replace the beet sugar. I describe the history, production, characteristics and their usage. These are mainly the natural sweeteners which are divided into the carbohydrate (sucrose, fructose, glucose, honey, lactose and sugar alcohols), non-carbohydrate (stevioside, thaumatin) and artificial align (aspartame, saccharin, cyclamates, acesulfame-K, sucralose).
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