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Endogenous contaminants in food
Greifenthalová, Ivana ; Kočí, Radka (referee) ; Vítová, Eva (advisor)
This work is focused on the problematic of endogenous contaminants in foods. The overview of all important contaminants arising in foods during their processing and storage by influence of physical, chemical and microbiological factors is given here. The origin and occurrence in foods, biological effects, toxicity and possible health importance and also legislation requirements are described in single compounds. Finally, the possibilities of regulation of their production are shortly mentioned.
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Residues of inhibitors in cow´s milk
STŘELEČKOVÁ, Veronika
Milk, in our territory frequently used cow?s milk, is very important nutrient. Its importance consists in the contents of valuable proteins, easily digestible milk fat, lactose, vitamins and minerals. The quality of raw cow?s milk is characterised by many indicators, for example total number of microorganisms, number of somatic cells, content of basic constituents (fat, protein, lactose, non-fat solids), freezing point or occurrence of undesirable foreign and inhibitory substances. Residuals of inhibitory substances (RIL) are one of the main criteria of raw milk hygienic quality, where they can appear for example due to prevention and treatment of mastitis. The risk of occurrence and spread of bacterial resistance, disruption of intestinal microflora, allergic reactions and RIL toxic effects, both in human and veterinary medicine, belong among the biggest risks of RIL presence in food and raw materials of animal origin, including milk. Inhibitory substances have an inhibiting effect on development and activity of microorganisms and in particular in milk industry they affect the activity of dairy cultures causing significant production problems. Their presence in milk causes problems when producing cheese, during fermentation of yoghurts and other fermentation during milk processing. Prevention of RIL occurrence depends especially on adherence to basic breeding and veterinary measures when using drugs and medicines, on technology discipline in primary production and regular and strict control of RIL contents in milk from the primary production up to processing when various screening detection methods are used. It is very important to deal with the matter of RIL in milk in connection with quality standards, national legislation and European Union legislation and to control methods used for their detection and verification.
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Effect of chosen substances in food of animal origin in development of lifestyle diseases
ZÁHORKOVÁ, Jana
This bachelor thesis is devoted to the effect of harmful substances found in animal foods that affect the development of civilization diseases. Fish can contain carcinogenic substances, such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), pesticides, methylmercury and lead. Higher consumption of red meat and meat products increases the risk of cancer. It can be caused by heme content or substances given into the food during heat treatment or preservative treatment of meat. These compounds include heterocyclic amines (HCA), polycyclic aromatic hydrocarbons (PAHs), N-nitrosocompounds (NOC), nitrates and nitrites. High intake of fat containing saturated fatty acids (SFA) and trans-unsaturated fatty acids (TFA), increases the risk of obesity, cardiovascular diseases, diabetes mellitus and cancer.
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The amendment to Act no. 110/1997 on food, new rules on food labeling and compliance with these rules
Steklý, Jaroslav ; Kadlecová, Eva (advisor) ; Pavla, Pavla (referee)
This thesis deals with the issue of food labelling, which is a topic that touches each of us. This topic is very broad and even when it is no longer effective amendment to the act on food no. 139/2014, it is very difficult for consumers in all the laws of the Czech Republic and EU regulations to navigate. The content of this theses does not and cannot be the task of this issue is completely clarified, but it aims to orientate in the basic law on foodstuffs no. 110/1997 Coll. amended by act no. 139/2014 and some other decrees and relevant regulations of the EC that directly affect food labelling. The practical part examines consumers' knowledge about food labeling, their interest in the information provided on labels and on compliance labeling frozen fish.
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Case-study of seniors’ lifestyle in relationships to healthy food
Krebsová, Michaela ; Chytková, Zuzana (advisor) ; Svobodová, Šárka (referee)
The aim of the presented case-study is a detection of the influence of seniors' lifestyle to healthy food. Qualitative approach to this topic should detect some selected aspects of seniors' lifestyle -- imaginations concern healthy food, real food shopping, and their real physical activities. Empirical pilot research was focused at sample of urban population, age 65+, living in Prague. Next aim of the master's thesis lies in economical consequences of seniors' lifestyle in relationships to healthy food and its potential changes. The thesis use methods like critical comparative approach to secondary data, qualitative approach in pilot sociological research, semi-structured interview, analyses and synthesis. The results are discussed in a framework of some sociological, demographical and marketing studies. The master's theses show seniors also like a challenging segment of populations in terms of great occasion for economic subjects and their business. General approach of the thesis is based on the contemporary concept of the relationships between active lifestyle and healthy food.
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Characterization and Identification of Wheat Allergens from Foodstuffs Containing Wheat
Goliáš, Jaroslav
In some cases, ordinarily accepted food can evoke harmful clinical symptoms which are brought on by sensitivity on specific component of foodstuff. This harmful reaction on accepted food is called food allergy and it tends to go up in the world's population in last years. The food allergy affects especially children as well as adults. The important role in the food allergy plays wheat and foodstuff containing components of wheat. Wheat allergens from flour is already well-known, but man accepts wheat in food in the treated form (heat treated food) what can decrease or increase allergenicity. Moreover, enzymes presented in gastrointestinal tract of man can influence allergenicity of wheat allergens too. The goal of this thesis is characterization of allergens presented in heat treated wheat foodstuff and in wheat foodstuff digested by enzymes in gastrointestinal tract of man. Characterization of these altered and newly produced allergens can help find better diagnostic techniques, increase specificity of detection of IgE antibodies, enable pointed therapy of allergic patients or find and apply new and suitable diet.
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Effects of chemopreventive compounds on cytochrome P450s
Křížková, Jitka ; Hodek, Petr (advisor) ; Helia, Otto (referee) ; Václavíková, Radka (referee)
CHARLES UNIVERSITY IN PRAGUE Faculty of Science Department of Biochemistry Effects of chemopreventive compounds on cytochrome P450s Summary of Ph.D. Thesis RNDr. Jitka Křížková Supervisor: prof. RNDr. Petr Hodek, CSc. Prague 2010 Introduction 1 Introduction According to the World Health Organization statistics, cancer is one of the leading causes of death in the human population worldwide for more than 50 years. Moreover, colorectal and gastrointestinal tract cancers are one of the main types of cancer leading to overall cancer mortality. Prevention consisting in a healthy lifestyle and a natural diet is suggested to be one of the main approaches to reduce cancer risk. In recent years, the consumption and use of dietary supplements containing concentrated chemopreventive phytochemicals increased dramatically. Flavonoids, as the most popular representatives of chemopreventive compounds, present in foods (fruits, vegetables, herbs, beverages) and dietary supplements have the potential to modulate the activity of xenobiotic-metabolizing enzymes [Hodek et al., 2002]. Among proteins interacting with flavonoids, cytochrome P450s (CYPs), monooxygenases metabolizing xenobiotics (e.g. drugs, carcinogens), play the most prominent role. The two members of CYP1A subfamily, CYP1A1 and CYP1A2, are involved in the...
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Structure of an immunoactive polysaccharide isolated from Korean mulberry fruit (Morus alba L.)
Bleha, R. ; Lee, J. S. ; Capek, P. ; Pohl, Radek ; Kim, H. B. ; Choi, D. J. ; Lee, S. ; Lee, J. ; Jang, S. J. ; Synytsya, A. ; Park, Y. I.
A water-soluble polysaccharide (JS-MP-1) was isolated from the water extract of Korean white mulberry fruits (Morus alba L.) by ethanol precipitation and then purified by DEAE-cellulose ion exchange chromatography. Obtained final polysaccharide (1600 KDa) consisted of galactose, arabinose and rhamnose as major neutral sugars. JS-MP-1 also contains galacturonic and glucuronic acids (4:1). Sugar linkage, FTIR and correlation NMR analyses confirmed that it is a rhamnogalacturonan type I (RG I), which contains the alternating sequence of 1,4-alpha-D-GalAp and 1,2-alpha-L-Rhap units in the backbone. Neutral sugar side chains of JS-MP1 were identified as (1 -> 5)-alpha-L-arabinan and arabinogalactan type II (AG II) having the (1 -> 6)-beta-D-galactan core. The arabinan side chains are bound to the backbone at the O-4 position of some alpha-L-Rhap units, while the way of linkage between RG I and AG II chains is unclear. It was demonstrated that JS-MP-1 significantly stimulates murine macrophage RAW 264.7 cells to release chemokines (RANTES and MIP-1 alpha) and proinflammatory cytokines like INF-alpha and IL-6, and induce the iNOS and COX-2 gene expression, which are responsible for the production of NO and prostaglandin PGE2, respectively. These results suggest that JS-MP-1 can act as a potent immunomodulator and these observations may support the applicability of this polysaccharide or the water extracts of mulberry fruit can be used as an immunotherapeutic adjuvant or health beneficial food material.
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Monitoring of Phytoestrogens Expression to the Milk and Milk Products
Watzková, Jarmila ; Rittich, Bohuslav (referee) ; Doležal, Petr (referee) ; Omelková, Jiřina (advisor)
Phytoestrogens are very intensively studied in recent years because they show different pharmacological effects on human health. For example, it was demonstrated that phytoestrogens reduce the risk of certain cancers (breast, prostate or colon), act as antioxidants in the body and affect the activity of certain enzymes. In addition, also it was demonstrated number of positive effects of soybean phytoestrogens on the health status of women in the menopause, such as reducing the risk of atherosclerotic cardiovascular disease or osteoporosis. Various technologically processed soy beans are important part of the feed rations mainly for high-lactating dairy cows, because they are a valuable source of the energy and high-quality protein, despite their negative effect on reproductive performance. Phytoestrogens consumed from the feed rations are hydrolyzed in the rumen of dairy cow and together with their metabolites are absorbed in the small intestine into the blood. They can be excreted from the body in urine or milk. From this perspective, cow's milk may become a source of phytoestrogens substances, especially equol in the human nutrition. On the other hand, some research results suggest possible potential risks associated with phytoestrogens intake in the diet on human health. At the some age (infants and young children) and group (vegetarians) categories may be dietary intake of phytoestrogens undiserable. According to most experts, a beneficial effect on human health prevail the potential risks. However, the risks associated with phytoestrogens intake in food can not be ignored and therefore phytoestrogens are still actual problem in the field of scientific research.
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