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Sensory properties of yogurt depending on various fruit composition
BOHDALOVÁ, Tereza
Diploma thesis is divided into two parts: theoretical and practical. The literary review is related to classification and chemical composition of yogurts and technological procedures in yogurt production. There is also a chapter on methods and application of sensory analysis in food industry. The aim of thesis was to evaluate three samples of yogurts differing in composition of strawberry mixture using the sensory profile and preference test. Questionnaire survey on consumer habits was a part of the research. The evaluators were students of the Faculty of Agriculture at the University of South Bohemia in České Budějovice and schoolchildren of Elementary School in Velešín.
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Fatty acid composition of bovine milk and milk products
MAŠKOVÁ, Gabriela
The thesis deals with changes in proportion of fatty acids in bovine milk. The aim of this study was to assess the profile of fatty acids in milk and subsequently in yoghurt produced from it. The thesis also evaluates the influence of breeding management, breed as well as region. The results of the thesis confirmed that processing of milk into yoghurt has little to no effect on fatty acids profile and proportion of fatty acids is stable. Processing milk into yoghurt alters nutritional value of the product only minimally and the changes in fatty acids profile are not statistically relevant. Profile of fatty acids in the end product was mostly influenced by breeding management, where nutritionally most valuable milk and therefore yoghurt comes from grazing dairy cows. Breed itself has influence more over content of main elements, such as fat or protein content, in milk rather than over fatty acids profile. Influence of region tightly relates to breeding management where in highlands pasturing is more common and in lowlands it is more common to have dairy cows in stables.
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Reologické vlastnosti bílých jogurtů
Fabianová, Jana
Diploma thesis in its theoretical part solves the problems of the milk assortment of dairy products, especially yogurt. It splits yogurt to the different types describing their production and chemical and physical properties. It is followed by a chapter devoted to the physical characteristics of foods, as well as their rheological properties, specifically viscosity. The practical part deals with the rheological properties of specific samples of commercially available yogurt. For these seven samples was determined by the density and the viscosity and shear stress versus shear rate. To assemble the flow and viscosity curves were used Ostwald-de Waeleho model, thanks to him, it was subsequently decided what kind of fluid as, Newton viscosity law, in the case of yogurt is. For the samples was determined as well as the time and temperature dependence of viscosity. Selected samples were analyzed fat content, which can be compared with data on the packaging of the sample.
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Návrh rodinné farmy zaměřené na chov koní a zpracování klisního mléka
Hájková, Lucie
This thesis describes the design of a family farm focused on horse breeding and ma-re´s milk processing. As part of this work is to develop a business plan for he proposed farm. This plan is also accompanied by a financial analysis of the proposed farm. Part of this thesis was the research focused on the solids content, titratable acidity, active acidi-ty, freezing point mare´s milk and how these technological characteristic affecting of the interim phase mares. Within the research focused was been tried and manufacture of yoghurt and icecream from mare´s milk. This research was carried out from April to September. Within the research were determined average values of 11,64 % dry matter, titratable acidity 3,85 °SH, active acidity of 7,47 pH, freezing point -0,553. The aim of the business plan will bet he establishment of an organic farm with breeding hucul, produ-ction and processing of mare´s milk. Secondary activites will be agroturism in which the farm will provide horseback riding. The total investment costs of the company are 13 016 824 Kč. Investment costs consist of the costs of setting up a company, purchase of land, construction of buildings and purchase of animals. The largest share of expendi-tures is the purchase of land in the amount of 10 375 274 Kč.
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Antimikrobiální působení rostlinných extraktů proti mikroorganismům izolovaným z mléka a mléčných výrobků
Štěrbová, Lucie
The diploma thesis investigates antimicrobial effects of plant extracts (ethereal oil) on microorganisms extracted from milk and milk products. The theoretical part focuses on joghurt and its production, main pathogenic microorganisms and their secondary metabolites affecting health. It presents antimicrobial effects of selected plants and procedures minimising or completely inhibiting the growth of microorganisms. Thyme and anise serve as the evidence for antimicrobial agents; the inhibitory effects of these ethereal plants were observed on the growth of selected microorganism groups (lactic acid bacteria, coliform bacteria, Enterococcus bacteria and yeast) by using disc diffusion test method. The RTS - 1C machine was used to simulate model conditions. Thyme ethereal extract with concentration of 1 and 10 % was used for disc diffusion test method. Anise ethereal extract with concentration of 0,7 % was used for observation of microorganisms' growth in model conditions.
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Dairy products in human nutrition, labelling according to czech legislation; consumer information and preferences
Dovolová, Barbora ; Kudlová, Eva (advisor) ; Dostálová, Jana (referee)
This bachelor thesis evaluates the dairy products labelling in the Czech Republic based on the requirements of the Czech legislation. It also pursues consumer's taste preferences, their interest and awareness of the dairy products labelling. The theoretical section mentions the history of dairying and the importance of milk products in human nutrition. The following chapters present individual dairy products and it described their production, labeling and division into kinds. The practical section reveals that the dairy products are labeled in accordance with the Czech legislation. The results are presented in the form of photos and tables (mini photobook). This part also examines whether the adult people interest in the dairy product labeling, how to orient in a range of dairy products and which products they prefer. The product evaluation was carried out in two big stores in Jablonec nad Nisou by using photographs. It was found that majority of companies indicates their milk products correctly. Identified deviations were discovered in the labelling of nutrition declaration or allergens. This is a relatively new requirements but very important. The questionnaire was found that 68 percent of people read informations on dairy products voluntarily. Most of the respondents consume especially milk, yoghurts and...
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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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Vliv vlákniny na senzorickou jakost fermentovaných mléčných výrobků
Ziková, Eva
The diploma thesis shows an influence of fibre on fermentated dairy products. The thesis describes technological features of fibre, types of fibre used in food processing and its acqusition for human nutrition. A yoghurt, as the most widespread example of fermentated dairy products, has been chosen for analysis. In the production of white yoghurt and cream, there was used wheat and bamboo fibre in 3% concentration. Fiber was added into raw milk before the pasteurization and then the classical production with maturation in a glass followed. Yogurt cream was consenquently made from yogurt. Evaluators during the senzory analysis evaluated 3 samples of yogurt or yogurt cream, in which one sample was without fibre addition. The results of the thesis is the recipe for milk yogurt product with a fiber content of 3%.
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Influence of aroma active compounds on flavour of yogurts
Malina, Jiří ; Babák, Libor (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the questions of determination of aroma active compounds present in yoghurts. These compounds are crucial for flavour of these fermented dairy products. Four types of yoghurts were analyzed, creamy (10 % of fat), medium-fat and medium-fat Bio (3 % of fat) and light (0,1 % of fat), produced by Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Five groups of different aroma active compounds such as ketones, aldehydes, organic acids and their esters and alcohols in different amounts were determined. These compounds are mostly metabolic products of Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, dairy yoghurt cultures usually used for yoghurt production. Less amounts are present in cow's milk or in dairy additives. Yoghurts were simultaneously sensorially evaluated using ranking test and scale test for determination of acceptability and flavour. The assessors were students and staffs of faculty of chemistry BUT.
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Influence of aroma active compounds on flavour of fruit yogurts
Malina, Lukáš ; Babák, Libor (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the determination of aroma compounds in fruit yoghurts. These compounds are crucial for flavour of these dairy products. Two types of fruit yoghurts were analyzed, creamy (8 % of fat) and light (less than 0,1 % of fat), with various fruit ingredients, produced in dairy Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Six groups of different aromatic compounds such as ketones, aldehydes, organic acids and their salts, alcohols and sulfides in different amounts were determined. These compounds have mostly microbiological origin (Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus are dairy yoghurt cultures usually used for yoghurt production), less amounts are present in cow's milk or in dairy additives. Yoghurts were simultaneously sensory evaluated using ranking test, scale test and pair test for determination of acceptability and flavour. The assessors were students and staffs faculty of chemistry VUT.
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