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Influence of particle size of cosmetic pigments on final properties product
Obručová, Kateřina ; Hurčíková, Andrea (referee) ; Zemanová, Jana (advisor)
This diploma thesis is focused on the study of the influence of the of size cosmetics pigments on the properties of the final product. This effect was studied on samples of make-up given by industry partner. Make-up samples were measured by the rheology method and the yield stress of all samples was determined. Scanning electron microscopy was used to determine the size and shape of the pigment particles. Particle size was also measured by dynamic light scattering, but the results were influenced by forming aggregates. To easier determination of the types of pigments in the sample was determined elemental composition of the pigments (Ti, Fe, O, Al) by EDS detector. Due to the unknown composition of make-up, the information was supplemented by X-ray powder diffraction (XRD) analysis, and it was possible to determine the compounds TiO2 (anatase and rutile), FeOOH and Fe2O3. The results obtained by these methods showed what pigments can be found in make-up samples, what their sizes and shapes are. It has been shown that the smaller the pigments are, the higher the viscosity and yield stress of the final product. The higher these quantities, the harder it is to handle the product.
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Weight control of soft cheese formed on a manual production line
Páral, Marek ; Zemanová, Jana (referee) ; Tomečková, Šárka (advisor)
The thesis deals with the control of the weight of soft cheeses during molding on a manual line. The theoretical part describes the classification of cheeses into groups, the basic characteristics of soft cheeses and their representatives. Furthemore, the whole technology of soft cheese production is processed and the effects on curd formation and factors influencing the weight of cheeses during molding are explained. The theoretical part ends with the basics of statistics for data processing. Basic measuring techniques (dry matter measurement, pH measurement, measurement of temperature and weight) were selected to determine the technological parameters (pH of whey, pH, dry matter and temperature of cheese grain, weight of cheese etc.) to describe the quality of grain in the experimental part of the thesis. The Design of Experiments method was used to find the optimal setting of the molding machine. Three partial experiments were designed and done. Results were verified in real production. The pH of whey was chosen to describe the grain quality. Two factors have been discovered that have a significant effect on the weigh of cheeses during molding, namely the position of the operator during molding and the amount of whey flowing into the forms with the cheese grain. The proposed molding modifications were successfully tested in production and no statistical difference was found between the weight of cheeses formed with the new setting of molding machine.
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Nutritional benefit of cricket flour
Šťastná, Martina ; Zemanová, Jana (referee) ; Němcová, Andrea (advisor)
Edible insects have been part of the diet of many countries across the world for several decades. It is becoming increasingly popular in the europian developed countries, mainly because of the content of nutritionally important substances. The theoretical part of the thesis deals with the characterization of edible insects in terms of nutritional benefits, explains the reasons and method of breeding edible insects. For the analysis of nutritionally active substances, flour of house cricket (Acheta domesticus) was used. A. domesticus belongs to the representatives of insects legalized from 1.1. 2018 on the EU market. Of the significantly nutritional substances, proteins, lipids, fatty acids, fiber and selected minerals were analyzed. In this study, optimalization of vertical electrophoresis SDS-PAGE was performed to determine protein fragment sizes. In the second part the influence of acricket flour addition protein bars was investigated by sensory analysis. In the experimental part that was found that cricket flour contains protein, lipids and fatty acids in significant amounts. It also contains important minerals for human health such as magnesium, potassium, iron or zinc. However, the sensory properties of protein bars for consumers were not very attractive.
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Influence of early and late drought on grain proteins content and composition in early and late variety of wheat
Vojteková, Vanesa ; Zemanová, Jana (referee) ; Hrstka, Miroslav (advisor)
In this bachelor thesis, the influence of early and late drought on grain protein content and composition in an early and late variety of winter wheat was studied. The varieties used were Avenue and Tobacco.One part of the plants was cultured under the conditions of early drought (bloom season), another part was grown under the conditions of late drought (grain filling season), the last part was grown under the conditions of natural irrigation. Half of the plants were fertilized using nitrogen fertilizer (200 kg N/ha), the second half of plants were without nitrogen fertilizer (0 kg N/ha). Wet gluten, crude protein content, gliadin and glutenin content were determined from flour samples. Results were evaluated by analysis of variance. Drought resistance depends on the genotype. Tobak genotype is more tolerant to climatic conditions, but the drought had a more significant effect on gliadin and glutenin ratio than on the Avenue genotype. Late drought increased wet gluten content in both genotypes and both types of fertilization. On the other hand, the early drought did not affect wet gluten content. Early drought decreased gliadin content, with the exception of Avenue genotype without fertilization. Early drought also increased glutenin content. Late drought increased glutenin content only in the unfertilized variant. Early drought increased glutenin content which leads to decreased gliadin content, especially for nitrogen fertilization. Late drought caused a decrease of gliadin and glutenin ratio, except for Tobak genotype with fertilization. Late drought increased crude protein content, except for Tobak genotype without fertilization. Early drought decreased crude protein content, especially for the unfertilized variant.
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Preparation and characterization of plant extracts for application to syrups
Šandová, Lucie ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
The aim of the diploma thesis was to produce herbal syrups from three selected herbs of the Lamiaceae family - Salvia officinalis, Melissa officinalis and Mentha piperita. First, extracts were prepared from these herbs by maceration in 25% of ethanol (60°C, 90 min). From the prepared herbal extracts, herbal syrups were made by mixing with syrup base (65% sucrose solution + lactic acid 2 g.l-1) in different ratios (2:1, 1:1, 1:2 - extract: base of the syrup). On the basis of sensory evaluation, a ratio of 1:1 was selected as optimal. The extracts and syrups produced were characterized in terms of volatile profile, phenolic content, antioxidant activity and antimicrobial activity. The produced syrups were also evaluated sensorially using scales, profile, and order test, and compared with similar commercial samples (Baťkovy sirupy s.r.o.). The HS-SPME-GC-MS method was used for the determination of volatile substances, the Folin-Cicalteu method for total phenolics, the TEAC method for antioxidant activity and the well and disc diffusion method for antimicrobial activity. 36 volatiles were found in model sage syrup, 29 in commercial syrup; 20 volatiles were found in model lemon balm syrup, 32 in commercial syrup; 25 volatiles were found in model mint syrup, 41 in commercial syrup. The quantitative distribution of the most important compounds in the commercial and manufactured syrups differed, with terpenes predominating in all samples. The content of phenolic compounds in syrups decreased in the order sage (570.1 mg.l-1) > lemon balm (378.9 mg.l-1) > mint (96.5 mg.l-1), antioxidant activity in the order lemon balm (332.0 µg.ml-1) > sage (185.6 µg.ml-1) > mint (115.8 µg.ml-1). Commercial syrups showed significantly higher phenolic compound content and antioxidant activity than manufactured syrups for all three herbs. In terms of sensory quality, mint syrup was considered the most palatable and sage syrup the least palatable (mint > lemon balm > sage); only in the case of lemon balm was the manufactured syrup considered better, more palatable than the commercial sample. It was reasonably liquid, clear of a pleasant colour, with a distinctly sweet, slightly herbaceous taste and a pleasant aroma.
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Influence of aroma compounds on sensory quality of sweets
Motúzová, Eliška ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This master´s thesis is focused on determination of aroma active compounds in non-chocolate sweets and their influence on sensory quality/flavour. The theoretical part describes production of non-chocolate sweets, characterizes aroma active compounds including allergenic ones, method for their determination by solid-phase microextraction and gas chromatography with mass detection. For experimental part were used as model samples gummy candies purchrased in regular market. Four flavors were used, specifically yellow (lemon), green (apple), red (strawberry) and orange (orange). The HS-SPME-GC-MS method was used to identify volatile aroma active compounds. To evalutate the sensory quality were used scales, a profile test, and a time course evaluation. Owerall 120 volatille compounds were identified including 8 allergens.
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Study of particles of various cosmetic pigments
Cerevatova, Kristina ; Opravil, Tomáš (referee) ; Zemanová, Jana (advisor)
The main focus areas of this master thesis include the writing of a literature review, which contains an overview and segregation of pigments which are used in the preparation of cosmetic products. The thesis is focused on the properties and characterization of pigments for use in cosmetology. The following focus is on legislation, more specifically on pigments that the cosmetic industry allows, limits and does not allow. The main part of this thesis is an overview of methods for the characterization of pigments. The practical part deals with the characterization of particles of selected cosmetic pigments by applying methods for determination of color, elemental and phase composition, particle size and morphology. The thesis is concluded by evaluation of the achieved results.
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Study of preservative systems for cosmetics
Šmétková, Zuzana ; Vítová, Eva (referee) ; Zemanová, Jana (advisor)
The aim of this diploma thesis was to prove the antimicrobial actvivity of the selected syntetic preservatives used in cosmetics, such as methylparaben, butylparaben, phenoxyethanol, bronopol, imidazolidinyl urea and methylisothaizolinone, in different concentrations (up to the highest permitted concentration and in increased concentrations), and of some essential oils, which are possible to use in cosmetics (essential oil from Eucalyptus globulus, Pimpinella anisum, Lavandula officinalis, Rosmarinus officinalis, Foeniculum vulgare, Mentha piperita, Juniperus communis and Pinus sylvestris). The effect was investigated in every preservative system alone, in order to evaluate the spectrum and the rate of each one. As indicator microorganism was chosen Bacillus subtilis and Penicillium chrysogenum. The used methods was disk difusion method and modify difusion method. From synthetic preservatives had the best effects bronopol, imidazolidinyl urea and methylisothiazolinone. From chosen natural antimicrobails had the effect against both indicator microorganisms the Mentha piperita, Foeniculum vulgare and Juniperus communis extracts.
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Study of extraction of biologically active substances into fatty base
Komárek, Šimon ; Vítová, Eva (referee) ; Zemanová, Jana (advisor)
This diploma thesis deals with macerates of comfrey (Symphytum officinale) in selected fats (food lard, cosmetic lard and almond oil). Selected fats were first characterized by dry matter content, saponification, acid, iodine number, peroxide value. At the same time, total and free fatty acids were determined using GC-FID. Macerates were prepared by extraction of comfrey roots with selected fats. In prepared macerates the change in acid and peroxide value was monitored, as well as the content of selected bioactive compounds. The content of total phytosterol and total carotenoid content was determined by UV-VIS spectrometry, phytosterols and carotenoids were also analysed using HPLC-DAD. Total phenolic content was measured using Folin-Ciocalteu reagent and antioxidant activity by ABTS assay. The measured properties were then compared with industrially produced comfrey ointment. In macerated fats the increase in acid and peroxide value was determined. Furthermore, an increase in the content of total phytosterols and total carotenoids was observed. Using HPLC-DAD the content of -sitosterol and stigmasterol was determined, but carotenoids were not detected. Of the tocopherols, only DL--tocopherol acetate was detected. During maceration, the content of total phenolic compound in fat increased, which caused a change in antioxidant activity.
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Obtaining and complex charaterization of Aronia spp. extracts
Seidlová, Kateřina ; Zemanová, Jana (referee) ; Veselá, Mária (advisor)
Aronia (Aronia melanocarpa) is a berry fruit with distinctive sensory characteristics and health-promoting properties. Polyphenols are the main bioactive compounds found in aronia including natural pigments – anthocyanins. Bioactive compounds are usually obtained from natural materials by extraction, in this work, two methods of extraction were compared – maceration and PHWE. Based on the total phenolic content, maceration was chosen as a more suitable method and then was optimized with statistical model – Design of Experiment. Optimal conditions were set to temperature of 30 °C, extraction agent 50 % ethanol, solid-solvent ratio 10 g per 50 ml and time of extraction for 30 minutes. Extract obtained under these conditions was characterised by total phenolic content – 1441 ± 90 mg/100 g DW, total anthocyanin content 943 ± 8 mg/100 g DW and antioxidation activity by ABTS 24,78 ± 0,09 molTE/g. In total of 25 volatile compounds were indentified in the optimal extract with content > 0,5 %. Major part created aldehydes and esters, with the main compounds being benzaldehyde (32,25 %) and methyl hexanoate (21,37 %).
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