|
|
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.
|
|
|
Study of biological effects of some plant materials
Drabíková, Nela ; Byrtusová, Dana (referee) ; Márová, Ivana (advisor)
The presented bachelor thesis deals with the preparation of aqueous, ethanolic and hexane extracts obtained from plant sources with increased content of oil, their characterization and cytotoxicity testing. In the theoretical part, a review focused on basic information about the used plants and their effects on the human body was elaborated. Furthermore, the active ingredients of the extracts, methods of their determination and the principle of the cytotoxicity test were described. In practical part the content of polyphenols and flavonoids was determined spectrophotometrically. Further, total antioxidant activity was measured. The fatty acids composition and the percentage of individual fatty acids were determined by gas chromatography. Next, MTT cytotoxicity assay was performed using human cell culture to confirm the safety of extracts for potential use in food, cosmetic and pharmaceutical industries.
|
|
|
Rosehip – the source of natural compounds
Motúzová, Eliška ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
The goal of this bachelor thesis was to study the antimicrobial activity of various extracts of rosehip tea. As well as to determinate concentration of biologically active compounds, polyfenols and flavonoids, and antioxidant activity in these teas. Teoretical part describes basic information about Rosa canina, general classification of tea, summary of biologically active compounds and basic methods of extraction. Practical part is focused on determination of anioxidant acivity, comcentration of polyfenols and flavonoids in tea extracts and detection of animicrobial activity of these extracts against bacterial strains Serratia marcescens and Micrococcus luteus. The results of this theasis show that aqueous extracts of rosehips tea are animicrobialy active. It was also found, that these extracts have hight contents of polyphenols and flavonoids.
|
|
|
Use and application of natural antimicrobial substances
Dzurická, Lucia ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis is focused on the study of antimicrobial activity of plant substances in combination with bacteriocins and the possibility of creating new encapsulated form of supplement which could be used in food and cosmetic products. 5 plant materials were selected: acerola, cinnamon, cloves, orange peel and yacon syrup. Nisin was chosen as the most suitable bacteriocin. In the theoretical part the components with antimicrobial and antioxidant activity are described, such as the materials of plants and animal origin used in this work. Also the possibility of increasing the antimicrobial effect and possible use of natural antimicrobial substances were described. In experimental part, the aqueous extracts of selected plant materials were firstly spectrophotometrically characterized for the content of total polyphenols, flavonoids and antioxidants. Selected substances were encapsulated into liposomes and subsequently preparation of liposomes coated with chitosan was optimized. The particles were tested for size, short and long term stability, encapsulation efficiency and antioxidant activity. Furthermore, the antimicrobial activities of selected components in nonencapsulated and encapsulated form were observed against four strains of microorganisms (Escherichia coli, Micrococcus luteus, Serratia marcescens and Candida glabrata). Also the expected synergisms of the antimicrobial effects of extracts in combination with nisin and prepared particles were observed.
|
|
|
Analysis of active substances contained in lavender and thyme extracts
Vašíčková, Milada ; Vysoká, Marie (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis is focued on active substances contained in lavandula officinalis and common thyme extracts, mainly their possible antimicrobial and antioxidant effects. The theoretical part desrcibes chosen plants, compounds with antimicrobial and antioxidant effects, methods how to obtain and identify said compounds. In the experimental part, aquenous, ethanolic and oil extracts were prepared. Mentioned extracts were spectrophotometrically characterised for total content of polyphenols, total content of flavonoids and antioxidant activity. In conclusion possible applications of extracts in food industry instead of synthetic preservatives and their fotification were discussed.
|
|
|
Sea buckthorn – the source of natural compounds
Blašková, Daniela ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
The main aim of the bachelor thesis was a research of common sea buckthorn, often denoted as "a plant of future". Botanic characteristics of the given bush, verification of biologically active substances and various concentration extract effects on selected kinds of microorganisms. In the theoretical part, the literature search is done, which discusses the characterization of the researched plant. The practical part deals with the application of selected methods of research, as follows: spectrophotometric determination of biologically active substances and microbiological verification of microbial activity on microorganisms, such as Bacillus subtilis, Serratia marcenscens and Micrococcus luteus. Considering the thesis results, it ensues that the given extracts do not show too great bacterial activity. Ex adverso, the extracts contain too big amount of determined active substances, in some cases.
|
|
|
Characterization and application of some plant antimicrobial substances
Bendová, Agáta ; Bokrová, Jitka (referee) ; Skoumalová, Petra (advisor)
The main goal of this bachelor thesis was the study of antioxidant and antibacterial effects of natural plant extracts and liposomes. The theoretical part was focused on description of natural antimicrobial and antioxidant substances from selected herbs and spices. Also bacterial resistance and methods used in work were described. In the experimental part basic characteristics of extracts from 12 kinds of herbs and spices (oil, alcohol and aqueous) were analyzed. Mainly content of polyphenols, flavonoids and the total antioxidant activity were determined. All extracts were also encapsulated into liposomes and the encapsulation effectivity, long-term stability and size and stability of liposomes were determined. The size of prepared liposomes was in range of 100 nm to 200 nm. Stability of the liposome particles was measured using a zeta potential and all prepared particles exhibited very good stability, but in term of long term stability were liposomes relatively unstable. Antibacterial activity was tested against Gram-positive Micrococcus luteus and Gram-negative Serratia marcescens. Encapsulation of extracts into liposome particles has greatly increased their antimicrobial effect and liposomes containing oil extracts from the goat, nutmeg and pepper and liposomes containing alcoholic extracts from star anise and cloves were the most effective against both strains. The prepared liposomes could be used as alternative to antibiotics and could be found application in the form of various antimicrobial gels for the cosmetic or pharmaceutical industry.
|
|
|
Preparation of antimicrobial gels with plant extract and oils
Benešová, Markéta ; Hoová, Julie (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis was focused on studying antimicrobial effects of natural plant extracts and their subsequent application. The research was mainly focused on the antioxidant and antimicrobial activity of plant extracts and liposomal particles with their contents. Theoretical part of thesis was focused on the topic of natural antimicrobial and antioxidant substances, problems with bacterial resistance as well as describing features and attributes of used herbs, and characterization of gels and liposomes. Within the experimental part of thesis, three types of extracts (aquatic, ethanol and oil), prepared from 10 different types of plants, were described. The content of phenolic, flavonoid substances, also antioxidant and antimicrobial activity were then determined. After that, the contents of all extracts were encapsulated into liposomes, and size, stability, encapsulation activity, also antioxidant and antimicrobial activity of those liposomes were determined. The size distribution was wide, but in terms of the measured zeta potential, most of the particles were stable. All prepared extracts and liposomes containing them were tested for their antimicrobial activity. The tests were performed on a gram-positive genus of Micrococcus luteus and a gram-negative type of Serratia marcescens. The most effective oil extracts against both species were eucalyptus and fir, as well as oil extract of cloves, along with aqueous extracts of mustard seeds, cloves and juniper, or ethanol extract of anise which also has high antimicrobial effects. Finally, these extracts and liposomes were applied into the gels, which could be found useful in the pharmaceutical industry, as an alternative to externally used antibiotics, or in the cosmetic industry.
|
|
|
Production and characterization of cheese with the addition of plant extract
Kučerka, Štefan ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This master´s thesis deals with production and characterization of fresh cheese with addition of herb extracts, specifically extracts from Plectranthus amboinicus and Echinacea purpurea. The purpose of this thesis was to prepare samples with higher sensory quality and nutritional value. Produced cheeses were characterized in terms of volatile (aroma) substances, fatty acid content, total phenolic substances, antioxidant activity and sensory quality. Cheese sample with added extract from E. purpurea reached the highest value of total phenolic compounds (0,172 ± 0,019 mgGAEg-1 of cheese) and antioxidant activity (91,2 ± 2,2 gTEACg-1 of cheese). Cheese sample with added extract from P. amboinicus, compared to standard cheese sample (without added extract) also reached higher values of total phenolic compounds and antioxidant activity. 43 volatile (aroma) compounds were identified in both samples with added extracts (P. amboinicus, E. purpurea), in standard cheese sample it was 33. In sample with E. purpurea camphor was present in high amount (15,23 %) responsible for the camphor aroma, camphor was also identified in small amount in sample with P. amboinicus. Highest volatile matter content was identified in sample with P. amboinicus. Standard cheese sample was rated as the best from the sensory perspective. Addition of extracts had negative effect on color, taste, and aroma perception of cheese. Strongest herbal taste was identified in sample with E. purpurea, brownish color of this sample manifested in lower pleasantness of color. Obtained results show, that extract addition increases the nutritional value of cheese (higher content of aromatic substances and phenolic compounds, higher antioxidant activity), but lowers sensory quality and overall consumer acceptability.
|
|
|
Antimicrobial effect of plant extracts
Konderla, Patrik ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The purpose of this bachelor thesis was to research the possible antimicrobial activity of various extracts of rosehip tea and also determine the antioxidant activity and the concentration of biologically active compounds (polyphenols and flavonoids) in these tea. Teoretical part describes basic information about plant Rosa canina and chemical composition of rosehips, summary of the natural biologically active compounds and general classification of tea. The practical part is focused on detection of antimicrobial activity of tea extracts against bacterial strains Serratia marcescens and Bacillus subtilis as well as spectrophotometrical determination of concentration polyphenols, flavonoids and overall antioxidant activity of these extracts. From the results flow the testing aqueous extracts rosehips tea analysed antimicrobial effects. Also was found, that these extracts has high content of polyphenols and flavonoids.
|
guest ::
