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Basic chemical characteristics of juices from selected red currants varieties
Rucká, Markéta ; Jurečková, Zuzana (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis is focused on the determination of basic chemical characteristics of selected red currants varieties from the Research and Breeding Institute of Pomology Holovousy Ltd. The theoretical part concentrates on general information about red currant, such as history of cultivation, origin and its expansion. There is also mention of the general characteristics of currant, currant building and significance of red currant cultivation. Chapter "Individual varieties" deals with the analysed varieties of red currants, especially its description and its biological properties, followed by an overview of the main substances contained in red currants and their brief description. Bachelor thesis also presents examples of the processing and the utilization of red currant in the food industry. The final chapter provides information about the individual determinations of the chemical characteristics of red currants, which include juice yield, soluble solids content, total dry matter content, pH, titratable acidity, formol number and reducing sugars. The experimental part describes the specific conditions and methods of individual determinations, followed by a summary of the results and their discussion. Variety Jesan showed the highest juice yield (63 ml per 100 g) and the highest pH value (3,16). The highest soluble solids content (13,94 %) and the highest formol number (22,83 ml of 0,1 M NaOH per 100 g) was determined in a variety Jonkheer van Tets. The highest dry matter value was detected for variety Rovada (14,48 %). The titratable acids content was highest in variety NŠLS 11/6 (403,88 mmol•kg-1). The highest concentration of reducing sugars was found in variety Tatran (8,17 %).
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The basic chemical parameters of several varieties of cherries
Boberová, Jana ; Vespalcová, Milena (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis deals with determination of basic chemical parameters in sweet cherry (Prunus avium). In the theoretical part, the taxonomic classification of the cherry, its botanical characteristics and the pomology of several cultivars are mentioned. Also, the history of cultivation, appropriate conditions and most common diseases are listed. The last chapter deals with the chemical composition of the fruits. In the experimental part, the determination of selected chemical parameters of various cultivars (Karešova, Napoleonova and Stark Gold) were determined. The content of total solids was determined in the range of 14.53–18.15 %, soluble solids 13.96–16.44 %, ash 0.34–0.44 %, reducing sugars 6.89–10.18 % and nitrogenous substances 0.056–0.116 %. Ascorbic acid content was set at 26.1–44.1 mg/kg. The titratable acidity was determined in the range of 6.15–8.86 g of predominant malic acid in 1 kg of cherry and a formol number was determined from 194 to 297 ml of 0.1 M NaOH per 1 kg of edible fraction. The amount of anthocyanins was determined at 4–686 mg cyanidin-3-rutinoside/kg and total phenolic compounds at 0.91–1.47 g gallic acid/kg. All data are based on fresh fruit weight.
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The basic chemical parameters of several varieties of sour cherries
Komárek, Šimon ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis deals with determination of basic chemical parameters in sour cherry (Prunus cerasus). Three different cultivars Köröšská, Pandy 6039 and Šumadinka were examined. The content of total solids varied from 13,32 to 15,22 %, soluble solid content amounted for 12,04–14,60 %, ash 0,4 %, reducing sugars 4,9–6,9 %, nitrogenous substances 0,11–0,12 %, L-ascorbic acid 343–456 mg/kg. Titratable acidity ranged from 15,1 to 21,8 g malic acid equivalent/kg, formol number 268–373 ml of 0,1 NaOH/kg. Total anthocyanins varied from 308 to 1104 mg cyanidin 3-glucoside equivalent/kg and total phenolics ranged from 1,05 to 3,99 g gallic acid equivalent/kg. All data are applied to fresh fruit weight.
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Basic chemical characteristics of juices of selected white gooseberry varieties
Zelníčková, Jaroslava ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
Theoretical part of this bachelor thesis includes taxonomical classification of gooseberry, deals with biological characteristics, active substances contained in fruits of gooseberry and its using as well with description of the methods by research detection. In the experimental part primary nutritional parameters of chosen gooseberry species were analysed including orientation juice yield, soluble solids, pH, dry matter, titratable acids, formol number and reducing sugars. There were analysed following species of gooseberry: Reflamba, Mucurines, Rixanta, Veliš, Citronový obří, Darek, Prima, Invicta, Zlatý fík a Zebín. Individual species and cultivars were compared based on the results.
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Chemical characteristics of fruit Mirabelle plum
Lukšová, Leona ; Pořízka, Jaromír (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with chemical and physical analysis of dried, lyophilized and stewed fruit, specially Mirabelle de Nancy. Theoretical part is devoted to the origin, the economic importance of plums, the botanical classification of Mirabelle de Nancy and other subspecies belonging to the genus Prunus. Subsequently the most economical method of preserving food called lyophilization is described. Part of this work is also the theme of raw food and description of biologically active substances contained in this fruit. In the experimental part, these characteristics of Mirabelle de Nancy were analyzed: total solids, soluble solids, determination of reducing sugars, titratable acidity, phenolic substances and ascorbic acid. It has been found that the lyophilized friut contains 16,8 wt. % of reducing sugars which is less than dried fruit with a value of 18,0; wt. %. It also contains less titratable acids with a value of 59,7 mmol/l versus 72,7 mmol/l in dried fruit.
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Basic chemical characteristics of cranberry juice
Cao, Ha Thuy ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis is about lingonberries and cranberries. It is mainly about berries which were used for chemical analysis. The berries are from the Research and Breeding Institute of Pomology Holovousy Ltd. and they have delivered six cultivars of lingonberries and three cultivars of cranberries. There is a research of general information about classification, botanical description, important chemical substances such as vitamins, natural colorants and products made in the industry. Furthermore there is descriprion of chemical methods for basic analysis. The next part of bachelor thesis is about how all these methods were applied to berry juice. What instruments and chemicals were used. First assessment was profit of juice which was about 50,00–60,00 %, but lingonberry Runo bilawskie has at least 31,49 % and cranberries have less profit too. Total solids were determined in the range of 11,40 % (Pilgrim) to 18,50 % (Runo bielawskie) and solitable solids are in range of 10,00 % (Pilgrim) to 16,08 % (Korál). Lingonberry contains more reducing sugars (8,81–12,92 %) than cranberry (7,90–9,03 %). Titratable acids are about 32,04–49,60 mmol.l-1 for lingonberry and about 55,40–60,67 mmol.l-1 for cranberry. The measurements show that pH of both berries are about 3. The most phenolic substances are found in range of 2187,11–3476,75 mg.l-1. Berries content anthocyans colorants in range of 54,91-65,29 mg.l-1 and the most in cranberry. All results are shown in charts and in the end there is a discussion and conclusion about methods and results.
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Monitoring of the selected parameters of grape wine before expedition
Trávníčková, Jiřina ; Pořízka, Jaromír (referee) ; Omelková, Jiřina (advisor)
Presented bachelor thesis is focused on laboratory monitoring and determination of the selected parameters of grape wine which includes specific gravity, alcoholic content, reducing sugar content, total titratable acidity, volatile acidity and total solids, sulfur dioxide content and protein and crystalline wine stability. The theoretical part deals with the wine production technology from the entry commodities to the bottling of mature wine. The aim of experimental part is a description of analytical determinations and complete wine sample analysis according to Regulation EEC No 2676/90 determining Community methods for the analysis of wines.
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Waste materials utilization for preparing hydrolysates for the fermentation phase.
Vadovičová, Natália ; Hrstka, Miroslav (referee) ; Babák, Libor (advisor)
Bachelor thesis focuses on the study and comparison of different types of hydrolysis, their optimization and maximization of yields for the upcoming fermentation. Orange peel was chosen as a substrate to conduct the experiments. First, the substrate was mechanically grinded to form a suspension. Each suspension then underwent one out of the examined methods of hydrolysis. Chosen methods were physical, such as microwaves, increased temperature or ultrasound, and chemical acidic and alkaline. Combinations of both types were also examined. The last optimized method was enzymatic hydrolysis. First set of experiments was conducted using enzymes Novozymes® NS50013 and NS50010. Production of cellulase and pectinase enzymes by A. niger during solid-state fermentation that lasted 10 days was also studied. The yields of reducing sugars of all the experiments were calculated using the Somogyi-Nelson method. Enzymatic hydrolysis was proven to be the most effective using the combination of both of the enzymes for a period of 96 hours at pH = 4.5 and temperature 45 °C. Yield of the reducing sugars under these conditions reached 27,4241 ± 0,0007 gl-1.
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Basic features of wine fermented from freerun and pressed must
Becková, Eliška ; Šalplachta, Jan (referee) ; Vespalcová, Milena (advisor)
My work is engaging in winemaking of white and red wines. Theoretic processes and goings during winemaking is describe in the first part of this work. It deals harvest of kapes, fermetation, clearing wine, chemical content of grapes and wine, deseases and abnormality of wines. There are this described choosen variettes, their grapes were processed practically. The third part of this work is dealed in practice winemaking and chemical analyse sof wines. Musts from the start of pressing, from the first dressing and from the end dressing fermented to the end dressing . They were fermented and than analysed by chemical and tasting tests. The discussion about the dependence of the quality of wines on the kind of the must during pressing is presented in the end of this work. The results are motivated by chemical analyses and senzoric tasting of the experts.
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Whey utilization with thermophilic microorganisms
Rychová, Alexandra ; Vítová, Eva (referee) ; Babák, Libor (advisor)
This diploma thesis studies the utilization of whey using thermophilic bacteria of the genus Thermus and Geobacillus. The whey stripped off proteins was used as a cultivation medium during experiments. The cultivation took place in the Erlenmeyer flasks, to assess the optimal conditions for microrganism’s growth. During the cultivation in the bioreactor, growth curves were established. The amount of whey utilization was assessed by analytical methods that determine the concentration of reducing saccharides (lactose) and chemical oxygen demand (COD) while studying the optimal conditions and a method determining the concentration of reducing saccharides during growth curves analysis.
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