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Impact of honey enrichment on its antimicrobial activity by bioactive substances against Escherichia coli
ŠEBESTOVÁ, Lucie
The main aim of this bachelor's thesis is to determine the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of both native honeys and honeys enriched with selected essential oils on the growth of Escherichia coli. In the theoretical part of the bachelor's thesis, bacteria Escherichia coli is briefly characterized, including its pathogenic strains and antibiotic resistance. Furthermore, honey is described, including its chemical composition and physiological effects. Additionally, essential oils are generally described, including their antimicrobial properties, along with a brief description of each selected oil. In the methodological part of the bachelor's thesis, procedures for preparing mediums, agar, inoculum, and the determination of their minimum inhibitory and bactericidal concentrations are described. MIC was measured spectrophotometrically in 96 well microtiter plates. MBC was determined by inoculation from the plate onto Mueller-Hinton agar followed by a 24hour incubation. A total of 3 native honeys were tested, which were then enriched with 8 selected essential oils. Essential oils with the addition of dimethyl sulfoxide (DMSO) were also tested. The results of the obtained data are statistically evaluated, graphically presented, and compared with scientific sources.
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Effect of honey fortification by selected bioactive substances on its antimicrobial activity against Staphylococcus aureus.
BOHDALOVÁ, Natálie
Staphylococcus aureus is a Gram-positive bacterium that can cause a wide range of infections, from mild skin infections to serious and life-threatening diseases. One of the main problems associated with this bacterium is still increasing to develop resistance to various types of antibiotics. Honey is a natural product made from the nectar of flowers collected by bees and stored in their combs. Honey has a wide range of ways it can be used for medicinal purposes, thanks to its beneficial effects. The main aim of this bachelor's thesis was to determine the minimum inhibitory and bactericidal concentrations of honeys, whether native or enriched with selected plant essential oils, or the plant essential oils themselves, on the growth of Staphylococcus aureus. The theoretical part focuses on basic information about the bacterium, the diseases it causes, and their treatment. Subsequently, the theoretical part delves into honey and its characteristics. Finally, plant essential oils and their properties are described. The methodological part of this thesis describes the individual tools and instruments that were used. The procedure for the preparation of honeys, plant essential oils and bacterial inoculum is also explained. Finally, the process of determining the minimum inhibitory and bactericidal concentrations is described. The determination of minimum inhibitory and bactericidal concentrations was carried out in 96-well microtiter plates, which were then measured spectrophotometrically. The results showed that the enrichment of honey with bioactive substances has in most cases positive properties on its antimicrobial activity against Staphylococcus aureus.
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Utilization of bees products in cosmetics
Kobza, Martin ; Bednář, Michal (referee) ; Zemanová, Jana (advisor)
This bachelor thesis is focused on the problem of utilization of bees products in cosmetics. The aim of this thesis was to elaborate a literature review focused on individual bee products, their properties and their utilization in cosmetics. Honey, beeswax, propolis, pollen, royal jelly, apisin are said to be the bee products. Properties, utilization, determination of kvalitative properties and aplication into cosmetic products of individual bee products are mentioned in this thesis. Beeswax is used in production of lipsticks, creams and for basis of smears (oily creams). Royal jelly is aplicated into lotions, face masks, lipsticks, night creams, hair waters, hydration preparations etc. Honey is used for preparation of shower gels, soaps, body milks, hydration creams. Propolis is added into creams, body milks, body lotions, shampoos, lipsticks, soaps and mouth sprays. Pollen has significant content of vitamins, aminoacids and other substances in nature form for cosmetics. These substances are important for nutrition, regeneration and hydration of skin. Apisin is used in pharmacologic preparations, like healing creams and smears.
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Determination of hydroxymethylfurfural in honey
Dohnalová, Barbora ; Slavíková, Zuzana (referee) ; Diviš, Pavel (advisor)
Honey is a valuable food of a natural nature that can be subject to adulteration for higher profits. One method of detecting this adulteration may be to determine hydroxymethylfurfural, the formation of which is promoted by heating. The theoretical part of the thesis deals with the types of honey, their origin, and the possibilities of their falsification. HMF, its occurrence and use and methods for its determination are also described. The practical part is devoted to the description of the experiment such as sample preparation, measurement and evaluation. The HPLC (high performance liquid chromatography) method was used to determine HMF in honey, which can be used to determine even very low concentrations. There were five samples for the experiment, four of them directly from the beekeeper and one from the retail chain. All samples were compared for HMF content. The highest concentration of HMF was determined in a sample of commercially available honey. In domestic honeys, the HMF content increased with the age of the honey. The content of HMF in all honeys complied with Decree No. 76/2003 Coll.
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The application of pollen as bioindicator of the environmental state
Marečková, Kateřina ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Pesticides and their excessive use lead to environmental pollution. Violation of the guidelines for their use disposal of empty containers could lead to contamination of water, soil and poisoning of animals and beneficial insects. Honey bee is useful creature on our planet. Good farming depends entirely on the pollination, but whole vegetal kingdom couldn’t exist it form known and used by mankind. Therefore, rules that protect these useful creatures against inadequate use of pesticides have been developed. This study focuses on the evaluation of the possibility to use bee products as bioindicators of the state of environment. Five active substances which are components of pesticides used in the treatment of agricultural field around Tasovice village were analysed in the pollen and honey. For sample preparation QuEChERS and SPE methods were used, gas chromatography with to mass spectrometric detection was employed as final analytical technique.
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Determination of honey authenticity and adulteration by anion exchange chromatography
Ždiniaková, Tereza ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
Cieľom tejto diplomovej práce je stanoviť kvalitu a zloženie medu, taktiež stanoviť jeho botanický pôvod na základe profilu sacharidov v mede. Med je prírodný produkt vysokej kvality a vďaka značnej spotrebe a nemalej trhovej hodnote je tiež terčom na falšovanie. S cieľom identifikovať podvody a cudzorodé látky, pochádzajúce z cukrových sirupov, boli analyzované oligosacharidy a polysacharidy na báze maltodextrínov. Teoretická časť popisuje chemické zloženie medu a hlavné princípy aplikovanej inštrumentálnej techniky. Poskytuje literárny prehľad existujúcich analytických metód na stanovenie sacharidov prítomných v mede a na odhalenie jeho falšovania. Boli definované hlavné body falšovania a autenticity, vrátane legislatívnych aspektov a opisu bežných druhov falšovania. Experimentálna časť obsahuje postupy, ktoré vedú k vývoju a optimalizácii chromatografických podmienok a parametrov elektrochemického detektora na stanovenie sacharidov a maltodextrínov (oligosacharidov a polysacharidov) vo vzorkách medu. Použitá analytická technika bola vysoko účinná aniónovo-výmenná chromatografia (HPAEC) spojená s pulzným amperometrickým detektorom (PAD). Vyvinutá a optimalizovaná chromatografická metóda bola taktiež validovaná z hľadiska linearity, dynamického rozsahu, analytických limitov, presnosti a správnosti. Na záver bola táto vypracovaná metóda úspešne zhodnotená analýzou autentických a falšovaných vzoriek medu rôzneho botanického pôvodu pochádzajúcich z členských štátov EÚ.
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Study of antimutagenic properties of selected kinds of honey
Lichnová, Andrea ; Melounová, Jitka (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on study of antimutagenic properties in selected kinds of honey and propolis. In honey extracts compounds with antimutagenic and antioxidant effect were analysed by spectrophotometry, RP/HPLC/UV-VIS, HPLC/PDA and on-line LC/MS. Further, effect of long-term storage on active compound levels was studied. Antimutagenic activity was tested by simple eukaryotic system - yeast strain Saccharomyces cerevisiae D7. The highest antimutagenic effect and simultaneously the highest stability of antimutagenity values was found in several kinds of multi-floral honey, rape seed honey, honey from eucalypt and orange flowers and in honeydew honey. Samples obtained from trade network exhibited at general lower antimutagenity values when compared with samples from bee-keeper. The highest content of total phenolics was detected in honey with royal yelly, the lowest content was measured in acacia honey. The highest values of total flavonoids exhibited buckwheat and eucalypt flower honey. Total phenolic content was substantially changed during long-term storage (decrease about 50 -70 %), while total flavonoid content was stable and no significant changes during storage were observed. Honey with high antimutagenity values exhibited also higher phenolic and predominantly flavonoid content and high antioxidant activity. Because of relative stability and low changes in most of honey samples during storage it can be concluded that honey belong to foodstuffs which are able to conserve their positive nutritive properties for a long time.
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Uses of active compounds from honey in cosmetic products
Balášová, Patricie ; Langová, Denisa (referee) ; Skoumalová, Petra (advisor)
The bachelor thesis was focused on the preparation and characterization of extracts and liposomes with active substances from chosen types of honey with the aim to apply these extracts to the cosmetic products. The extraction of active substances from chosen material was optimized during the work. As the most suitable organic solvent for extraction was chosen diethyl ether. All the extracts were tested on the content of total polyphenols, sugars and antioxidation activity. The final samples were also tested on the content of flavonoids. Extracts were encapsulated to the liposomes, which were tested especially for their antioxidation activity, size and stability. Then, extracts and liposome particles were applied to the cosmetic products. Cosmetic creams and gels were prepared and tested for antioxidation activity and antimicrobial activity against the strains Serattia marcescens and Micrococcus luteus. Antimicrobial activity of gels was proved especially against the strain of grampositive bacterias – Micrococcus luteus. From this point of view another one testing strain was chosen – Propionibacterium acnes. Finally, the chosen liposomes were tested for their contact with human cells, immortalized keratinocytes HaCat. No cytotoxic effect was observed and tested materials can be applied to cosmetics against acne.
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Control of careless heating of honeys using HPLC and MAS techniques
Radvanová, Tereza ; Punčochářová, Lenka (referee) ; Diviš, Pavel (advisor)
Honey is a popular natural food. Liquid honey without any trace of crystalization is much more desirable. Therefore, honey undergoes heat treatment to dissolve formed crystals. Exposure to high temperetures can cause chemical changes of honey components and formation of undesirable reaction products. When honey is heated 5-hydroxymethylfurfural can be formed and activity of enzyme diastase lowers. In this bachelor thesis, 5-hydroxymethylfurfural content was analyzed by HPLC-MS and activity of enzyme diastase was determined with commercial Phadebas method followed by MAS in 11 honey samples. Analysis determined 5 honey samples with above the limit content of 5-hydroxymethylfurfural and 1 sample with insufficient diastase activity. 5-hydroxymethylfurfural content in honey correlated well with diastase activity values (r = 0,612).
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Use of analytical methods and chemometry to verify the geographical authenticity of honey
Marková, Lucie ; Křikala, Jakub (referee) ; Diviš, Pavel (advisor)
The teoretical part of this bachelor thesis is focused on the process of producing the honey by bees, its composition and means of its adulteration or ways to detect substandard products. The experimental part describes methodes, which were used to observe the samples. Sacharides, organic acids, mineral content, the amount of dry matter, titration acidity and conductivity were meassured. Obtained data were used for differentiation the Czech and foreign honey. The result of the statistical analysis shows the calcium, copper and glucose content are suitable paramteres to differentiate the Czech honey from that externals. Theese parameters could be used to distinguish the two different geographical origin of honey. Nevertheless, the total evaluation seems to be insufficient for differentiation these two groups. The efficiency could be icreased by the including more samples for analysis, or meassuring more parameters. Finally, some of the parameters were used for quality control of honey.
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