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A study of the possibility of waste pastries using for the bioproduction of selected metabolites
Hudečková, Helena ; Vránová, Dana (referee) ; Babák, Libor (advisor)
The aim of this diploma thesis was to study the possibility of using waste bread to bioproduction of selected metabolites. As bakery waste was used waste bread that came from coffee-house “Zastávka”. Bread was pre-treated by grinding into small particles and then it was made to form 15% w/v suspension, which was subjected to enzymatic hydrolysis. For the hydrolysis has been used the -amylase for liquefaction of the substrate and that was followed by a glucoamylase which sacharificated the substrate. There have been several methods of hydrolysis from which was chosen the optimal method for pre-treatment of the substrate prior to fermentation. The effectivity and a process of hydrolysis were determined spectrophotometrically by Somogyi-Nelson method. Final yields of glucose from hydrolysis were determined by HPLC method. Enzymatic hydrolysis was followed by fermentation, which was carried out in two ways, namely by adjusting the pH of the hydrolyzate to pH 5, and without pH adjustment. During the fermentation was carried out sampling in which was determined the content of glucose, glycerol and ethanol by HPLC method. The yeasts Saccharomyces cerevisiae were used for the fermentation which was performed at 30 °C. High yield of glucose was achieved by hydrolysis in two steps (70,28 gl-1), but for the fermentation was used mixed hydrolysis (second method of mixed hydrolysis) with yield 67,94 gl-1. High ethanol yield was achieved during fermentation without treatment pH, namely 31,5 gl-1.
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UTILIZATION OF FOOD PROCESSING WASTE FOR LACTIC ACID AND ETHANOL PRODUCTION
Hudečková, Helena ; Kráčmar, Stanislav (referee) ; Buňka, František (referee) ; Márová, Ivana (advisor)
The doctoral thesis is focused on the microbial production of lactic acid and ethanol using food processing waste as substrate. Coffee processing waste (spent coffee grounds), wine production waste (grape pomace) and orange processing waste (orange peel) were chosen as substrates for experiments. The theoretical part is dedicated to summarizing current knowledge about waste from food production and possibilities of its processing. It also deals with selected metabolites (lactic acid, ethanol) to which these wastes can be used. Part of the experiments was focused on the characterization and optimization of hydrolysis to maximize the amount of fermentable saccharides. Different combinations of chemical, physical and enzymatic hydrolysis of selected substrates have been tested. Subsequently, a suitable strain for lactic acid and ethanol production was searched for. In the case of lactic acid production, 7 bacterial strains were selected (Lactobacillus casei CCM 4798, Bacillus coagulans CCM 2013, Bacillus coagulans CCM 2658, Lactobacillus rhamnosus CCM 1825T, Lactobacillus delbruckii subsp. bulgaricus CCM 7190, Lactobacillus plantarum CCM 7039T, Streptococcus thermophilus CCM 4757). These strains were first cultivated on the synthetic media containing different kind of saccharides. Afterward, the cultivation on the waste biomass hydrolysates were tested. In the case of ethanol production, 2 yeast strains kmeny (S. cerevisiae CNCTC 6646 a S. cerevisiae CNCTC 6651) were cultivated on hydrolysates of individual waste substrates. Subsequently, the experiments focused on the production of lactic acid and ethanol on hydrolysates of waste biomass in bioreactor were done. The last part of this doctoral thesis deals with the microaerobic pretreatment of lignocellulosic biomass to increase the production of organic acids during the acetogenic phase of anaerobic digestion.
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Analysis and characterization of beta-glucans from some natural sources
Vít, Radek ; Hudečková, Helena (referee) ; Márová, Ivana (advisor)
The aim of the bachelor thesis is to test and characterize commercially available products with declared -glucans content. The theoretical part describes -glucans, their possible sources, properties and utilization. Further, the theoretical part is focused on methods for determination of -glucan content. Saccharomyces cerevisiae yeast and oyster mushroom fungus are available as commercial sources of -glucans. Next individual groups of the active substances and principles of the methods used for their characterization are described too. In experimental part of this work the extracts from five commercially available sources of -glucans were prepared and characterized. Antioxidant activity, total polyphenols, proteins and carbohydrates were determined. For selected products, the content of vitamin C using HPLC and the lipid content using GC-FID were determine as well. An enzymatic method was used to determine the -glucan content. Two samples of the highest antioxidant activity were then subjected to antimicrobial and MTT tests.
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Encapsulation of probiotics for use in nutritional products for children
Šmídová, Veronika ; Hudečková, Helena (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis is focused on optimization and development of probiotic food supplement with attractive look and active ingredient, like prebiotic or “superfood”, which are there for afford useful substances for organism. In the theoretical part is focused on probiotics and its encapsulation, also on prebiotics, which are used for work and screening probiotics food supplements in our market. The practical part is focused on optimization of composition of new probiotic food supplement, polysaccharide particles in the shape of a teddy bear were prepared. At first, the basic composition was optimized, as the best alginate-agar particles were determined. Addition of nutritionally valuable ingredients was also optimized. Particles with inulin, acerola, chia fiber, yacon syrup, chlorella and spirulina were prepared. Another part of this work was focused on the determination of the viability of probiotic bacteria Lactobacillus acidophilus and Bifidobacterium breve in various forms and after exposed to model digestion. The highest viability of the cells was measured after encapsulation of lyophilized cells into a polysaccharide particle. Prepared particles were finally subjected to a sensory analysis.
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Study of growth and metabolic properties of selected microorganisms
Hudečková, Helena ; Šupinová, Petra (referee) ; Babák, Libor (advisor)
The aim of this Bachelor thesis was study of the growth and production of selected metabolites of microorganisms, namely Lactobacillus casei and Saccharomyces cerevisiae. Microorganisms were cultivated in Erlenmeyer flasks by using the recommended media for their growth. The growth curves were determined from the values of optical density and concentration of biomass. Samples were then analyzed by HPLC for determination of the content of glucose and ethanol in S. cerevisiae and the content of glucose and lactic acid by L. casei.
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Production of organic acids by fibrous microscopic fungi and utilization of their biomass for removal of risk elements
Juglová, Zuzana ; Hudečková, Helena (referee) ; Urík,, Martin (advisor)
The aim of this bachelor thesis was to determine the most advantageous method for production of organic acids by microscopic flamentous fungus Aspergillus niger and to evaluate mercury bioaccumulation efficiency on collected fungal biomass. The theoretical part focuses primarily on utilization, metabolism and production on individual organic acids. This is followed by section focused on the toxicity of mercury and the principles of bioaccumulation of heavy metals in biomass. The experimental part focuses mainly on the optimization of cultivation, determination of content of produced organic acids, depending on the type of cultivation. Second point of practicle part is evaluating of mercury bioaccumulation depending on the initial concentration of mercury in solution. In overall comparison, the best type of cultivation is dynamic. Higher biomass yeild resulted in higher production of organic acids. The higher biomass synthesis is also beneficial for bioaccumulation of mercury.
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Development of cosmetics emulsions with hemp extract
Baranová, Barbora ; Hudečková, Helena (referee) ; Márová, Ivana (advisor)
The hemp plant contains many biologically significant substances that are used in the food, pharmaceutical and cosmetic industries. Hemp extracts and oils are increasingly used in the cosmetics industry due to their antioxidant and antimicrobial activity. This bachelor's thesis deals with the characterization of hemp extracts and their use in the creation formulation of a moisturizing skin cream, the stability and assessment of the effects of this cream. In the theoretical part, individual hemp fractions, their composition and use in the cosmetics industry were discussed. As part of the experimental, the content of phenolic substances, flavonoids, chlorophylls and antioxidants in hemp extracts obtained by extraction using ethanol and tetrafluoroethane was analyzed spectrophotometrically. The content of cannabinoids was assessed by HPLC and TLC methods. The best characteristics were demonstrated by the ethanolic extracts of the Santhica and Fibror varieties, therefore they were used in the creation of a skin emulsion and its stability was tested by centrifugal and stress test. The skin cream was created with purely natural substances that are safe, environmentally friendly and effective. The resulting final product has demonstrated stability for approximately eight months and has been tested by volunteers. Their feedback confirmed the product's potential, with 70% reporting more hydrated and soothed skin. The development of a natural facial moisturizer with hemp extract provides a safer and more effective alternative to synthetic cosmetics and addresses the growing demand for sustainable and eco-friendly skin care options.
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Production of lignin-degrading enzymes by Phanerochaete chrysosporium
Péčiová, Bianka ; Hudečková, Helena (referee) ; Kovalčík, Adriána (advisor)
This diploma thesis deals with the study of the production of ligninolytic enzymes produced by the mold P. chrysosporium and subsequently their immobilization. The theoretical part describes the selected production microorganism, principles of action of ligninolytic enzymes (lignin-peroxidase, manganese-dependent peroxidase and laccase) and methods of their immobilization. In the experimental part, optimal conditions of the production of ligninolytic enzymes by P. chrysosporium were monitored as a composition of culture medium with different glucose content and with using two different inducers: lignin and guaiacol. During the 14-day cultivation cycles, the enzyme activity of lignin-peroxidase, manganese-dependent peroxidase and laccase was monitored on each day of cultivation. Based on the optimized enzyme production procedure, the enzymes were subsequently immobilized by various methods: by method of forming enzyme aggregates (CLEA), adsorption on bacterial cellulose (BC) and a combination of both (CLEA + BC). The CLEA method proved to be the most effective, but there was problem with isolation of enzyme aggregates. Therefore, immobilization on bacterial cellulose associated with the enzymes aggregates was chosen as the most advantageous. With this method, the operational stability of the immobilized enzymes was monitored in 7 consecutive reaction cycles. Subsequently, CLEA and CLEA with BC were used to modify the model phenolic substance, where the alkali lignin was selected. For both sets of immobilizers was confirmed the effect of the enzymes on the lignin structure by measuring the molecular weight (Mw) and polydispersity index (PI).
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Effect of preservatives on the sensory properties of ham
Bělohoubková, Tereza ; Hudečková, Helena (referee) ; Mikulíková, Renata (advisor)
The Master’s thesis contemplates the effect of additives on sensory properties of ham. The theoretical part incorporates history of meat product preservation and characterization of ham from legislative and compositional point of view. Technological ham making process in the Czech republic as well as worldwide and nutritional value of cooked ham are described. Further on the thesis contains a description of traditional and new sensory evaluation methods. Discussion of current solution of the issue concludes the theoretical part. In the practical part technological highest standard ham making process was optimalized, without the use of industrial manufacturing devices. Samples of ham containing nitrite salting mix and sodium nitrate along with a ham sample without the additon of preservatives were prepared. Total content of moisture, proteins, ash and fats was determined in these samples by regular standardized methods, that were statistically compared by paired test or analysis of variance (ANOVA) with results obtained by FoodScanTM instrument. Fatty acids content was determined by gas chromatography with FID detector in samples containing additives and a sample without additives. Effect of additive adittion in ham on nutritional characteristics, fatty acids content and on concentration of TBARS (lipid oxidation products) was investigated. Within sensory analysis effect of additives on sensory properties of ham was studied by CATA method. Sensory panel consisted of consumers. In the first sensory analysis of ham samples with addition of preservatives (nitrite salting mix, sodium nitrate, sodium acetate and sodium lactate) consumers picked ham containing nitrite salting mix as the most acceptable. The chosen sample served as a base for the second sensory analysis of samples containing antioxidants (sodium erythorbate, butylhydroxyanisole, butylhydroxytoluene, sodium ascorbate) and stabilizers (sodium hydrogen phosphate and potassium phosphate). In the second sensory analysis the consumers had difficulty distinguishing the samples. Part of the sensory analysis was a marketing research and a study of ham additives perception from a consumer’s point of view.
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Recipe of a food supplement based on bioactive substances isolated from Prunus spinosa
Červinková, Zuzana ; Hudečková, Helena (referee) ; Kovalčík, Adriána (advisor)
Blackthorn fruits (Prunus spinosa) are small blue-purple drupes containing a range of bioactive substances that give them diverse biological effects. They are traditionally used not only in folk medicine, as they are attributed with many preventive and therapeutic effects. The presented master´s thesis deals with the preparation and characterization of an ethanol extract and dietary supplements based on bioactive substances isolated from the fruits of blackthorn. The ethanol extract was prepared by maceration fresh Prunus spinosa fruits in 40% alcohol. The extract was analyzed for the polyphenols (2111.39±11.32 mg GAE/l), flavonoids (903.89±5.08 mg CAE/l) and anthocyanins (165.24±0.38 mg CGE/l) content, antioxidant (11.99±0.40 mmol TE/l) and antimicrobial activity, phenolic compounds profile and sugars profile. The ethanolic extract exhibited antibacterial effect against the gram-positive bacterium Micrococcus luteus and gram-negative bacterium Escherichia coli but was not effective against the yeast Candida glabrata. After gentle concentration on a vacuum evaporator, the extract was used to prepare a dietary supplement. Two types of dietary supplements were prepared, namely gelatine candies with blackthorn fruit extract and gelatine capsules filled with lyophilized fruit powder. The nutritional profile of these products, content of bioactive substances (i.e. total polyphenols, flavonoids, and anthocyanins), phenolic compound profile and antioxidant activity were characterized. Additionally, the release of polyphenols was monitored during a simulated in vitro digestion. The gelatine candies with different extract concentrations (5, 10, 15 and 20 %) were subjected to sensory evaluation, where the aim was to optimize the addition of the extract to the gelatine matrix. According to the preferences of the evaluators, the sample with 15 % extract was rated as the best in terms of overall taste. In the ranking test, this sample was ranked second, behind the sample with 5 % extract, which, on the other hand, received a worse sensory profile rating. The thesis also included monitoring the effect of freezing, lyophilization, and drying on the bioactive compounds content (i.e. total polyphenols, flavonoids, anthocyanins) and antioxidant activity of Prunus spinosa fruits. The highest contents of total polyphenols (57.49±0.33 mg GAE/g DW), flavonoids (45.75±0.12 mg CAE/g DW) and anthocyanins (6.41±0.19 mg CGE/g DW) were quantified in lyophilized fruits, but the highest antioxidant activity (281.72±0.70 mol TE/g DW) was observed in frozen fruits. A statistically significant moderately strong positive correlation (0.641) of antioxidant activity and total flavonoids was observed for the analyzed samples. The results of the thesis showed a great potential for the use of blackthorn berries in the nutraceutical industry, where they can contribute as active additives to increasing both the bioactive and nutritional quality of dietary supplements.
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