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Study of volatile compounds of chocolate depending on geographical origin of cocoa beans
Kubínová, Martina ; Kovalčík, Adriána (referee) ; Vítová, Eva (advisor)
Diploma thesis is focused on cocoa beans volatile compounds from various region (Tanzania, Haiti, Ecuador, Madagascar and Peru) and chocolate bars made of them. The main aim was to judge diferences between samples according to geographycal origin. At the same time, samples of chocolates with different content of cocoa solids (50%, 70% „organic“, 70%, 78%, 90%) and a sample of cocoa powder from the common market were analyzed. Volatiles were identified and semiquantified by HS-SPME-GC-MS. A total of 86 volatile substances were identified, they were divided into 7 groups according to the nature of the odor: fruit tones (17), nut and chocolate (16), astringent and sour (12), unspecified (14), sweet nad honey (10), earthy (9) and floral (8). The data were transformed into a 2D graph by analyzing the main component according to selected distinguishing varibles. The difference in the volatile substances of cocoa beans depending on the geographical origin were confirmed using principal component analysis.
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Development of method for determination of qualitative parameters of cocoa powder
Vránová, Petra ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
The theoretical part of the master’s thesis is focused on a brief botanical characterization of the cacao tree and its most famous varieties discussed. Furthermore, the chemical composition of cocoa beans is described with an emphasis on theobromine and caffeine. There is also mention of the cocoa beans the cocoa bean processing technology for cocoa liquor and cocoa powder, which are then used in food industry. Additionally there is a shorta short description of the legal requirements relating to cocoa. In this part are also two chapters are devoted to the description of instrumentation of high performance liquid chromatography (HPLC) and inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental part deals with analyzes of cocoa powder, cocoa beans, cocoa liquor and waste cocoa beans sold as a "tea mixture". A total of 10 legislation-recommended parameters have been identified in the listed raw materials, such as caffeine, theobromine and sucrose, heavy metal and potassium, fat content etc. The highest content of theobromine was determined in cocoa powder 178.363 mgl-1, caffeine in cocoa beans 16.096 mgl-1. All samples analyzed contained a little amount of sucrose as expected, the highest concentration was found in the tea mixture samples in both the water: ethanol sample of 84.069 mgl-1, and the sample solution in water of 65.897 mgl-1.
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Study of volatile compounds of chocolate depending on geographical origin of cocoa beans
Kubínová, Martina ; Kovalčík, Adriána (referee) ; Vítová, Eva (advisor)
Diploma thesis is focused on cocoa beans volatile compounds from various region (Tanzania, Haiti, Ecuador, Madagascar and Peru) and chocolate bars made of them. The main aim was to judge diferences between samples according to geographycal origin. At the same time, samples of chocolates with different content of cocoa solids (50%, 70% „organic“, 70%, 78%, 90%) and a sample of cocoa powder from the common market were analyzed. Volatiles were identified and semiquantified by HS-SPME-GC-MS. A total of 86 volatile substances were identified, they were divided into 7 groups according to the nature of the odor: fruit tones (17), nut and chocolate (16), astringent and sour (12), unspecified (14), sweet nad honey (10), earthy (9) and floral (8). The data were transformed into a 2D graph by analyzing the main component according to selected distinguishing varibles. The difference in the volatile substances of cocoa beans depending on the geographical origin were confirmed using principal component analysis.
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Development of method for determination of qualitative parameters of cocoa powder
Vránová, Petra ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
The theoretical part of the master’s thesis is focused on a brief botanical characterization of the cacao tree and its most famous varieties discussed. Furthermore, the chemical composition of cocoa beans is described with an emphasis on theobromine and caffeine. There is also mention of the cocoa beans the cocoa bean processing technology for cocoa liquor and cocoa powder, which are then used in food industry. Additionally there is a shorta short description of the legal requirements relating to cocoa. In this part are also two chapters are devoted to the description of instrumentation of high performance liquid chromatography (HPLC) and inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental part deals with analyzes of cocoa powder, cocoa beans, cocoa liquor and waste cocoa beans sold as a "tea mixture". A total of 10 legislation-recommended parameters have been identified in the listed raw materials, such as caffeine, theobromine and sucrose, heavy metal and potassium, fat content etc. The highest content of theobromine was determined in cocoa powder 178.363 mgl-1, caffeine in cocoa beans 16.096 mgl-1. All samples analyzed contained a little amount of sucrose as expected, the highest concentration was found in the tea mixture samples in both the water: ethanol sample of 84.069 mgl-1, and the sample solution in water of 65.897 mgl-1.
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Dietitians attitude toward chosen modern food products
Novák, Ondřej ; Meisnerová, Eva (advisor) ; Chrpová, Diana (referee)
The aim of this thesis is to ascertain view of dietitians on "superfoods" promoted through the media. The thesis consists of a theoretical and practical part. The theoretical part is supported by foreign scholarly articles and clinical studies and is focusing on characteristics of five specific examples of "superfoods" (chia seeds, quinoa, goji berries, acai and cocoa beans). Each of these foods is examined primarily in terms of chemical composition, content of most significant substances and their prospective effect on human health. The practical part is focused on dietitians and their opinion on "superfoods". This part includes survey with the aim to answer the questions whether the dietitians have cognizance of "superfoods", if they recommend them in their practice and what is their opinion on this kind of food. Data evaluation is illustrated in graphs which concluded that "superfoods" are acknowledged by 90, 9% of asked dietitians and specific examples evaluated in this thesis are acknowledged by more than a half of respondents. In their practice the "superfoods" are recommended by 41, 7% of respondents and their opinion can be evaluated only from certain points of view therefore the attitude towards "superfoods" cannot be clearly determined as positive or negative. Only 10, 4% of respondents...
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Vliv surovin a technologie na senzorickou jakost čokolády
ŠINÁKLOVÁ, Petra
The theoretical part of the diploma thesis titled "The Effect of Raw Materials and Technology on the Sensory Quality of Chocolate" describes the commodity and the related legislation, the raw materials used for the production of chocolate, the substitutes for some basic raw materials, and the production procedures. The theoretical part also describes the significance of chocolate for human nutrition and analyses the defects that may occur in chocolate. The objective of the practical part is to ascertain the opinions of a selected group of consumers on the selected sorts of chocolates. The results are divided into two parts. In the first part I carried out a collective evaluation (men and women together), and in the second part I evaluated the results separately for each gender (men separately from women) in order to find out any differences in the sensory evaluation of this commodity between the groups. The evaluators' preferences between three sorts of dark chocolates of the same brand with a different cocoa quantity were tested and evaluated by means of a ranking test. The preferences between two sorts of dark chocolates with orange flavour produced by two different producers were evaluated by means of a pair test. I also carried out and evaluated a questionnaire survey aimed at ascertaining the liking for various sorts of chocolates with different composition.
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The world market of cocoa and chocolate
Voborníková, Martina ; Gullová, Soňa (advisor) ; Klosová, Anna (referee)
The thesis depicts the world market of cocoa and chocolate dand current trends influencing the chocolate industry. The aim of this paper is to describe current trends in consumption of chocolate on basis of the analysis of international trade of cocoa and chocolate. I also analyse their impact on consumption of chocolate and chocolate confectionery in Czech Republic. The paper focuses on the history, classification and main producecrs as well as main sellers on the international market of the mainstream products and first class (fine) ones. The paper is devided into three parts. The first part briefly analyses the international trade of cocoa, the second part focuses on the international trade with chocolate and chocolate industry with its current trends, the last part is dedicated to the consumption of chocolate in Czech Republic and its main trends.
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Investing in commodities
Václavík, Michael ; Drozen, František (advisor) ; Šípek, Ladislav (referee)
The purpose of this bachelor thesis is analysis of selected commodity -- cocoa beans, evaluation of the possibilities of investing in the commodity with focus on the most famous financial derivatives -- futures. The first chapter, so called theoretical part is focused on matters of commodity market -- stock market and its participants, analysis of the market and investment opportunities on the commodities market, especially with futures. The second chapter focuses on the cocoa beans market analysis, the most important participants and with the help of fundamental analysis the most important factors influencing supply and demand for the cocoa beans, their impact on the price development. The conclusion summarizes the basic knowledge and evaluates investment opportunities primarily for the smaller investor.
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World Cocoa Market and Global Production of Cocoa
Pokorná, Iveta ; Jiránková, Martina (advisor) ; Horák, Jiří (referee)
This bachelor thesis deals with the world market of cocoa beans. It aims to describe the global cocoa production and the most important producing countries as well as analyze collected data of trade flows with this commodity. The work is divided into three interrelated parts. The first chapter is dedicated to the general characteristic of the cocoa tree and the history of its growing. The second chapter presents the quantity of the production in particular areas of harvesting during the second half of the twentieth century and at the same time it mentions business relations between producers and consumers. The last chapter raises the issue of Fair Trade on the example of cocoa.
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