|
|
Optimization of Hericium erinaceus Cultivation and Subsequent Fermentation with Probiotics
Radvanová, Tereza ; Vršanská, Martina (referee) ; Hudečková, Helena (advisor)
The focus of this diploma thesis is to optimize cultivation of the hericium erinaceus mushroom on cereal substrates with subsequent fermentation with probiotic bacteria. Theoretical part of this thesis focuses on description of the mushroom hericium erinaceus and its nutritional value, biological properties, other uses and cultivation. Furthermore, an overview of the nutritional value of the used cereal substrates is provided, along with the characterization of probiotics, their biological effects, and metabolism. Finally, a chapter dedicated to the description of the traditional koji fermentation process was included. In the experimental part, the cultivation of hericium erinaceus was optimized on seven cereal substrates – barley groats, cornmeal, wheat bran, buckwheat, amaranth, white and red quinoa. Using spectrophotometric methods, the content of water soluble proteins, total carbohydrates, total phenolic compounds, flavonoids, and antioxidant activity was determined in the cereal substrates themselves and substrates enriched with mycelium. Furthermore, the content of fatty acids was determined in the samples using the gass chromatography method and lipophilic compounds were analyzed using high performance liquid chromatography. Cereal substrates enriched with mycelium showed increased antioxidant activity and concentrations of water soluble proteins, phenolic compounds, flavonoids, and lipids. Moreover, elevated concentrations of tocopherols, ubiquinone, and ergosterol were detected through high performance liquid chromatography analysis. Substrates with abundant mycelial growth, such as barley groats, cornmeal, red quinoa, and amaranth, were selected for fermentation with probiotic bacteria Lactobacillus rhamnosus. After the fermentation process, spectrophotometric methods were repeated, and the concentration of lactic acid was determined using high performance liquid chromatography. Samples with probiotics showed a slight increase in their antioxidant activity, concentration of phenolic compounds, flavonoids, and water soluble proteins. The concentration of lactic acid in control samples and samples with probiotics was almost unchanged. The obtained results from this study suggest that cereals enriched with mycelium and the fermentation product of probiotics could be utilized in the development of dietary supplements or functional foods.
|
|
|
Possibilities of processing the fruit of lesser-known fruit tree species
Vachta, Jonáš ; Hudečková, Helena (referee) ; Mikulíková, Renata (advisor)
This diploma thesis deals with the possibilities of using the fruits of common quince (Cydonia oblonga), common medlar (Mespillus germanica) and flowering quince (Chaenomeles speciosa) for food purposes, specifically for the production of jellies and jams. The goal was to create a product that would capture the character of the fruit used, preserve its beneficial properties, such as aromas and the content of bioactive substances, and at the same time be pleasant for consumers. A total of three types of products were prepared, namely gelatin jelly, agar jelly and jam for each type of fruit used. The product samples were subjected to sensory analyses, the aim of which was to determine the optimal addition of sugar to the product, to determine the overall consumer acceptability of the individual samples, and in the case of jelly, also to compare the sensory properties of the gelatin and agar variants. For chemical analyses, model samples were prepared, the composition corresponding to the best sensorially evaluated samples from each type of product. The total content of polyphenols, the total content of flavonoids, the content of vitamin C, the content of lipophilic pigments, ubiquinone and phytosterols and the profile of volatile compounds in individual samples were studied. The analysis results showed that the jams, as heat-processed products, generally retained a greater amount of bioactive substances compared to the jelly samples, and in certain cases even a greater amount than the fruit samples. The jelly samples, on the other hand, retained a greater amount of the original fruit aroma.
|
|
|
Use of citrus fruits in the food industry
Havlíková, Michaela ; Hudečková, Helena (referee) ; Mikulíková, Renata (advisor)
The main objective of the thesis was to prepare marmalades, jellies, and dried slices of citrus fruits. Three types of citrus fruits: orange, grapefruit, and pomelo, were chosen for this thesis. The nutritional characteristics of the prepared products were determined including volatile matter content, dry matter content, pigment content, lipophilic content, and vitamin C content. The aforementioned products were also subjected to sensory analysis to assess their taste, aroma, texture, colour, and overall acceptability. The theoretical part describes the legislation dealing with citrus processing, marmalades, dried fruit and jelly confectionery. Further, the characteristics of the aforementioned food products and the characteristics of citrus fruits are also given. The theoretical part also deals with the theory of the methods used, i.e. sensory analysis, gas chromatography with mass spectrometry, and high-performance liquid chromatography. The experimental part describes the preparation of samples and the performance of individual determinations. In the sensory analysis, marmalades, jellies, and dried sheets were evaluated separately. The evaluators assessed their acceptability depending on the citrus used. The volatile substances were also determined by gas chromatography-mass spectrometry. The moisture and dry matter of the products were determined by drying and the pigments and lipophilic substances contained in the products were determined by high-performance liquid chromatography.
|
|
|
Preparation of Cosmetic Product Based on Microbial Extracts
Reichertová, Klára ; Trachtová, Štěpánka (referee) ; Hudečková, Helena (advisor)
This thesis is focused on the preparation of a cosmetic product based on microbial extracts. The thesis is divided into two main parts, theoretical and practical. The theoretical part describes the types of cultured microorganisms, microbial metabolites, legislation and safety of cosmetic products, composition of human skin and last but not least the applied analyses. The experimental part deals with the use of waste products of the food industry, specifically coffee grounds as a substrate for culture media. Furthermore, the cultivation is studied with a focus on the gain of metabolites useful in the cosmetic industry, the analysis of these metabolites by GC/FID and HPLC/PDA. The work addresses the preparation of microbial extracts, their testing including determination of polyphenol and flavonoid content and characterization of antioxidant activity and antimicrobial activity tested on bacterial cultures of Esterichia coli and Staphylococus epidermidis. The application of the analysed extracts and their application to the final product is also addressed. The last chapter discussed in this thesis to test the final product using Visioscope PC–35, instrument and performing sensory analysis. The cultured strains were Phaffia rhodozyma CCY 77-1-1, Cystophilobasidium macerans CCY 10-1-2, Rhodosporidium toruloides CCY 062-002-004 Chlorella vulgaris CCALA 924. The biomass obtained by cocultivation of Phaffia rhodozyma CCY 77-1-1 and Chlorella vulgaris CCALA 924 as well as the biomass of these two microorganisms cultured separately were used for the preparation of microbial extracts.
|
|
|
Optimization of Combined Chitosan Particles and their Characterization for Application Use
Netopilík, Tibor ; Hudečková, Helena (referee) ; Márová, Ivana (advisor)
The thesis deals with the preparation and characterization of nanoparticles for cosmetic and food applications. The thesis explores various methods of preparing nanoparticles, including liposomes and chitosomes, and analyses their properties and stability in different model environments. The experimental part includes the determination of the encapsulation efficiency of different vitamins by HPLC and UV-VIS spectrophotometry. Results show the influence of various factors such as time, type of environment and method of preparation on stability and efficiency of the nanoparticles. Furthermore, the optimization of the preparation is carried out chitosomes using ultrasound and magnetic stirrer. Cosmetic products enriched with these nanoparticles were developed and their sensory analysis was proved. This work contributes to the understanding of nanoparticle preparation processes and provides useful information for the development of new cosmetic and food products with improved properties and stability.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
guest ::
RSS feed.