• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 17
  • 13
  • 10
  • 5
  • 3
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 56
  • 56
  • 16
  • 15
  • 12
  • 11
  • 9
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Změny obsahu mastných kyselin během výroby modelového sýra / Changes of fatty acids during production of model cheese

Janoušková, Kateřina January 2017 (has links)
This thesis deals with the identification and quantification of free and bound fatty acids in model cheese samples of the Moravský bochník type, which were produced at Tomas Bata University in Zlín by a standard technological procedure. In a theoretical part of the thesis, the issues of lipids, fatty acids, as well as the characteristics of high cooked cheeses including Moravský bochník, microbial cultures used in their production, and the possibilities of fatty acids determination are summarized. The ČSN EN ISO 1735:2005 method was chosen for the lipid extraction from cheese samples. Present free and bound fatty acids were identified and quantified by gas chromatography with flame-ionization detection after conversion to methylesters by acid esterification with bortrifluoride as a catalyst. In total 32 fatty acids were identified in cheese samples, the highest amount of caproic, caprylic, capric, lauric, myristic, palmitic, stearic and oleic acids.
12

COMPOSTOS VOLÁTEIS E PARÂMETROS DE QUALIDADE DE DIFERENTES GENÓTIPOS DE FRUTOS DE BUTIA ODORATA. / VOLATILE COMPOUNDS AND QUALITY PARAMETERS FROM DIFFERENT GENOTYPES OF BUTIA ODORATA.

Ferrão, Tassiane dos Santos 27 February 2012 (has links)
The Butia odorata has received special attention from the scientific community because of their nutritional and functional properties that have been revealed, in addition to its rightdown sensory characteristics. The aim of this study was to characterize different genotypes from Butia odorata fruit collected in Santa Maria - RS (SM) and Santa Rosa - RS (SR) regions during three consecutive harvests in relation to various physical and chemical properties. Many analyses were performed like: biometric, color and quality parameters, fatty acid composition in the Butia pulp. An HS-SPME method was developed for the isolation and subsequent quantification (GC-FID) and identification (GC/MS) of volatile compounds (VCs). The biometric parameters results showed pulp yields between 40.38 and 73.91%. The color of the pulp ranged between yellow and orange shades. TSS ranged between 12.39 and 15.50 °Brix, acidity between 0.69 and 2.26 g% citric acid and pH between 3.17 and 3.95. The fruit had humidity between 78.04 and 85.85 g%; ashes between 0.47 and 0.77 g%; protein between 0.57 and 0.93 g%, crude fiber between 0.84 and 4.02 g%; lipid between 0.12 and 2.27 g%. The fatty acids such as palmitic acid, linoleic and linolenic acids were found in abundance. It was possible to observe the partial discrimination between the two regions in the PCA using the physico-chemical variables. The samples from SR characterized by high scores for lipids and palmitic acid, while SM samples showed a higher humidity and TSS. The method employed use DVB/CAR/PDMS fiber for the VCs extraction of the centrifuged Butia pulp , added with 30% NaCl, and maintaining the system at a temperature of 35 °C for 45 minutes, under stirring. The volatile fraction was analyzed in GC and were identified 77 compounds among acids (5), alcohols (14), aldehydes (9), ketones (12), lactones (3), terpenes (2) and esters (34). The ethyl hexanoate compound was the major compound in almost samples. The PCA from VCs enabled to realize grouping of samples into two groups according to region of origin. The fruits from Santa Maria showed a high content of esters and the fruits from Santa Rosa had higher concentrations of alcohols and aldehydes. An exploratory analysis of the variables of physico-chemical composition and volatile of the samples was observed using PCA. In the graphs analysis also realized a partial separation of samples according to their region: the samples SM2-10 and RS1-11 distanced themselves from the other and it indicates greater particularity in their chemical compositions. Therefore the fruits (Butia odorata) showed great variability in biometric characteristics, physico-chemical and volatile profiles according to region of origin. It indicates a strong influence of soil and climatic factors. In this study, the nutritional characteristics and high yield pulp of some Butia fruits demonstrated the high potential for fresh consumption or for the manufacture of processed products / O butiá (Butia odorata) tem recebido especial atenção da comunidade científica, em virtude de suas propriedades nutritivas e funcionais que estão sendo reveladas, além das suas características sensoriais peculiares, ainda pouco exploradas. Desta forma, o objetivo do presente trabalho foi caracterizar diferentes genótipos de frutos de butiazeiros coletados nas regiões de Santa Maria RS (SM) e Santa Rosa RS (SR) em três safras consecutivas, quanto as diversas propriedades físicoquímicas. Foram realizadas análises biométricas, de cor, dos parâmetros de qualidade, composição centesimal e ácidos graxos da polpa do butiá, além do desenvolvimento de método de isolamento por SPME com posterior quantificação (GC-FID) e identificação (GC/MS) dos compostos voláteis (CVs). Os resultados dos parâmetros biométricos revelaram rendimentos de polpa, entre 40,38 e 73,91%. A cor da polpa oscilou em tons de amarelo e laranja. Os SST variaram entre 12,39 e 15,50 °Brix, a acidez entre 0,69 e 2,26 g% em ácido cítrico e o pH entre 3,17 e 3,95. As frutas apresentaram umidade entre 78,04 e 85,85 g%; cinzas entre 0,47 e 0,77 g%, proteína entre 0,57 e 0,93 g%, fibra bruta entre 0,84 e 4,02 g% e lipídios de 0,12 a 2,27 g%. Os ácidos graxos encontrados em maior abundância foram o ácido palmítico, linoléico e linolênico. Na Análise dos Componentes Principais (PCA) empregando as variáveis físico-químicas observou-se a discriminação parcial entre as duas regiões, sendo as amostras da região de SR caracterizadas por elevados escores para lipídios e ácido palmítico, enquanto que as da região de SM apresentaram, em geral, maior umidade e teor de SST. O método desenvolvido emprega o uso da fibra DVB/CAR/PDMS para a extração dos CVs da polpa de butiá centrifugada, adicionada de 30% de NaCl, e mantendo o sistema a uma temperatura de 35 ºC por 45 minutos, sob agitação. A fração volátil foi analisada em GC e nela identificados 77 compostos entre ácidos (5), alcoóis (14), aldeídos (9), cetonas (12), lactonas (3), terpenos (2) e, principalmente, ésteres (34). Entre estes se destacou o hexanoato de etila como composto majoritário. A PCA dos CVs possibilitou ver o agrupamento das amostras em dois grupos conforme a região de origem, onde, em geral, os butiás de Santa Maria apresentaram elevado teor de ésteres, enquanto os de Santa Rosa obtiveram maiores concentrações de alcoóis e aldeídos. Uma análise exploratória entre as variáveis de composição físico-química e volátil das amostras estudadas foram observadas através de uma PCA. Na visualização dos gráficos notou-se também uma parcial separação das amostras quanto à região de origem, sendo que as amostras SM2-10 e SR1-11 distanciaram-se das demais, indicando maior particularidade em suas composições químicas. Sendo assim, os butiás apresentaram grande variabilidade em suas características biométricas, físicoquímicas e nos perfis voláteis em função da região de origem e safra e, portanto, apresentou forte influência de fatores edafoclimáticos. Sobretudo, as características nutricionais e o alto rendimento de polpa de alguns frutos de butiás evidenciaram, neste estudo, o alto potencial para consumo in natura ou mesmo para a fabricação de produtos processados.
13

Óleo essencial de casca-preciosa (Aniba canelilla (H. B. K. ) Mez) : validação de metodologia bioanalítica e estudo de permeação cutânea in vitro / “Precious-bark” essential oil (Aniba canelilla (H. B. K.) Mez) : bioanalytical method validation and in vitro cutaneous permeation study

Kreutz, Tainá January 2017 (has links)
A Aniba canelilla (H.B.K.) Mez é uma planta aromática proveniente da região amazônica cujo óleo essencial apresenta como componentes majoritários o 1-nitro-2-feniletano e o metileugenol. Apesar das atividades antifúngicas e anti-inflamatórias cientificamente comprovadas e do uso popular do óleo para o tratamento de dermatites, acnes e feridas, não existe até o momento um estudo que verse sobre a quantificação desses compostos na pele. O objetivo deste trabalho foi a validação de um método bioanalítico otimizado por microextração em fase sólida no modo headspace em cromatógrafo gasoso com detector de ionização de chama (HS-SPME-GC-FID) para a determinação do 1-nitro-2-feniletano e metileugenol a partir do óleo essencial em diferentes amostras de estudo de permeação cutânea in vitro. Uma metodologia foi desenvolvida e validada por HS-SPME-GC-FID. A faixa da curva de calibração foi de 2,08 - 207,87 μg.mL-1 para o 1-nitro-2-feniletano e de 0,40-40,41 μg.mL-1 para o metileugenol. A presença de matriz e as características intrínsecas da metodologia de HS-SPME requereram uma transformação da curva de calibração. A transformação logarítmica (Log10) foi então aplicada aos dados e os resultados apresentaram homocedasticidade, resíduos dispersos, coeficiente de determinação (r²> 0,99) e recuperação adequados. Estudos de permeação cutânea foram realizados em células de Franz com diferentes quantidades (20, 100 e 200 μL) de óleo essencial de A. canelilla para avaliar o perfil de permeação e retenção em pele de orelha suína e fluido receptor. A análise das amostras nas condições validadas mostrou uma grande permeação e retenção dos compostos na seguinte ordem: fluido receptor >> derme >> epiderme >> estrato córneo. Verificou-se um aumento progressivo e dependência na retenção com base na quantidade aplicada no compartimento doador e grande retenção principalmente no fluido receptor e derme, resultado este compatível com as características físico-químicas de Log P, afinidade ao ambiente hidrofílico e lipofílico, tamanho e peso molecular do 1-nitro-2-feniletano e metileugenol. Em conclusão, o método proposto por HS-SPME-GC-FID para quantificar os compostos majoritários do óleo essencial de A. canelilla em amostras de pele de orelha suína e fluido receptor foi seletivo, preciso, exato e adequado, e pode ser utilizado em análises futuras. / Aniba canelilla (H.B.K.) Mez is an aromatic plant from the Amazon region whose essential oil has 1-nitro-2-phenylethane and methyleugenol as major compounds. Despite of the scientifically proved antifungal and anti-inflammatory activities and the popular use of oil for the treatment of dermatitis, acnes and wounds, there is no study up to date about the quantification of these compounds in skin samples. The aim of this study was the validation of an optimized bioanalytical method by solid phase microextraction on headspace mode in gas chromatograph with flame ionization detector (HS-SPME-GC-FID) for the determination of 1-nitro-2-phenylethane and methyleugenol from the essential oil in different samples of in vitro cutaneous permeation study. A methodology was developed and validated by HS-SPME-GC-FID. The ranges of calibration curves were 2.08 - 207.87 μg.mL-1 for 1-nitro-2-phenylethane and 0.40 - 40.41 μg.mL-1 for methyleugenol. The presence of matrix and the intrinsic characteristics of the HS-SPME methodology required a transformation to the calibration curves. The logarithmic transformation (Log10) was then applied to the data and the results showed homoscedasticity, dispersed residues, and adequate coefficient of determination (r²> 0.99) and recovery. Skin permeation studies were performed on Franz cells with different amounts (20, 100 and 200 μL) of A. canelilla essential oil to evaluate the skin permeation and retention profile in porcine ear skin and receptor fluid. The analysis of the samples under the validated conditions showed a high permeation and retention of the major compounds in the following order: receptor fluid >> dermis >> epidermis >> stratum corneum. A progressive increase and retention dependence were observed based on the amount applied in the donor compartment, and large retention mainly on the receptor fluid and dermis was observed, in accordance with the physicochemical characteristics of Log P, affinity to the hydrophilic and lipophilic environment, size and molecular weight of 1-nitro-2-phenylethane and methyleugenol. In conclusion, the method proposed by HS-SPME-GC-FID to quantify the major compounds of A. canelilla essential oil in porcine ear skin and receptor fluid samples was selective, accurate, precise and adequate, and can be used in future analyzes.
14

Óleo essencial de casca-preciosa (Aniba canelilla (H. B. K. ) Mez) : validação de metodologia bioanalítica e estudo de permeação cutânea in vitro / “Precious-bark” essential oil (Aniba canelilla (H. B. K.) Mez) : bioanalytical method validation and in vitro cutaneous permeation study

Kreutz, Tainá January 2017 (has links)
A Aniba canelilla (H.B.K.) Mez é uma planta aromática proveniente da região amazônica cujo óleo essencial apresenta como componentes majoritários o 1-nitro-2-feniletano e o metileugenol. Apesar das atividades antifúngicas e anti-inflamatórias cientificamente comprovadas e do uso popular do óleo para o tratamento de dermatites, acnes e feridas, não existe até o momento um estudo que verse sobre a quantificação desses compostos na pele. O objetivo deste trabalho foi a validação de um método bioanalítico otimizado por microextração em fase sólida no modo headspace em cromatógrafo gasoso com detector de ionização de chama (HS-SPME-GC-FID) para a determinação do 1-nitro-2-feniletano e metileugenol a partir do óleo essencial em diferentes amostras de estudo de permeação cutânea in vitro. Uma metodologia foi desenvolvida e validada por HS-SPME-GC-FID. A faixa da curva de calibração foi de 2,08 - 207,87 μg.mL-1 para o 1-nitro-2-feniletano e de 0,40-40,41 μg.mL-1 para o metileugenol. A presença de matriz e as características intrínsecas da metodologia de HS-SPME requereram uma transformação da curva de calibração. A transformação logarítmica (Log10) foi então aplicada aos dados e os resultados apresentaram homocedasticidade, resíduos dispersos, coeficiente de determinação (r²> 0,99) e recuperação adequados. Estudos de permeação cutânea foram realizados em células de Franz com diferentes quantidades (20, 100 e 200 μL) de óleo essencial de A. canelilla para avaliar o perfil de permeação e retenção em pele de orelha suína e fluido receptor. A análise das amostras nas condições validadas mostrou uma grande permeação e retenção dos compostos na seguinte ordem: fluido receptor >> derme >> epiderme >> estrato córneo. Verificou-se um aumento progressivo e dependência na retenção com base na quantidade aplicada no compartimento doador e grande retenção principalmente no fluido receptor e derme, resultado este compatível com as características físico-químicas de Log P, afinidade ao ambiente hidrofílico e lipofílico, tamanho e peso molecular do 1-nitro-2-feniletano e metileugenol. Em conclusão, o método proposto por HS-SPME-GC-FID para quantificar os compostos majoritários do óleo essencial de A. canelilla em amostras de pele de orelha suína e fluido receptor foi seletivo, preciso, exato e adequado, e pode ser utilizado em análises futuras. / Aniba canelilla (H.B.K.) Mez is an aromatic plant from the Amazon region whose essential oil has 1-nitro-2-phenylethane and methyleugenol as major compounds. Despite of the scientifically proved antifungal and anti-inflammatory activities and the popular use of oil for the treatment of dermatitis, acnes and wounds, there is no study up to date about the quantification of these compounds in skin samples. The aim of this study was the validation of an optimized bioanalytical method by solid phase microextraction on headspace mode in gas chromatograph with flame ionization detector (HS-SPME-GC-FID) for the determination of 1-nitro-2-phenylethane and methyleugenol from the essential oil in different samples of in vitro cutaneous permeation study. A methodology was developed and validated by HS-SPME-GC-FID. The ranges of calibration curves were 2.08 - 207.87 μg.mL-1 for 1-nitro-2-phenylethane and 0.40 - 40.41 μg.mL-1 for methyleugenol. The presence of matrix and the intrinsic characteristics of the HS-SPME methodology required a transformation to the calibration curves. The logarithmic transformation (Log10) was then applied to the data and the results showed homoscedasticity, dispersed residues, and adequate coefficient of determination (r²> 0.99) and recovery. Skin permeation studies were performed on Franz cells with different amounts (20, 100 and 200 μL) of A. canelilla essential oil to evaluate the skin permeation and retention profile in porcine ear skin and receptor fluid. The analysis of the samples under the validated conditions showed a high permeation and retention of the major compounds in the following order: receptor fluid >> dermis >> epidermis >> stratum corneum. A progressive increase and retention dependence were observed based on the amount applied in the donor compartment, and large retention mainly on the receptor fluid and dermis was observed, in accordance with the physicochemical characteristics of Log P, affinity to the hydrophilic and lipophilic environment, size and molecular weight of 1-nitro-2-phenylethane and methyleugenol. In conclusion, the method proposed by HS-SPME-GC-FID to quantify the major compounds of A. canelilla essential oil in porcine ear skin and receptor fluid samples was selective, accurate, precise and adequate, and can be used in future analyzes.
15

Óleo essencial de casca-preciosa (Aniba canelilla (H. B. K. ) Mez) : validação de metodologia bioanalítica e estudo de permeação cutânea in vitro / “Precious-bark” essential oil (Aniba canelilla (H. B. K.) Mez) : bioanalytical method validation and in vitro cutaneous permeation study

Kreutz, Tainá January 2017 (has links)
A Aniba canelilla (H.B.K.) Mez é uma planta aromática proveniente da região amazônica cujo óleo essencial apresenta como componentes majoritários o 1-nitro-2-feniletano e o metileugenol. Apesar das atividades antifúngicas e anti-inflamatórias cientificamente comprovadas e do uso popular do óleo para o tratamento de dermatites, acnes e feridas, não existe até o momento um estudo que verse sobre a quantificação desses compostos na pele. O objetivo deste trabalho foi a validação de um método bioanalítico otimizado por microextração em fase sólida no modo headspace em cromatógrafo gasoso com detector de ionização de chama (HS-SPME-GC-FID) para a determinação do 1-nitro-2-feniletano e metileugenol a partir do óleo essencial em diferentes amostras de estudo de permeação cutânea in vitro. Uma metodologia foi desenvolvida e validada por HS-SPME-GC-FID. A faixa da curva de calibração foi de 2,08 - 207,87 μg.mL-1 para o 1-nitro-2-feniletano e de 0,40-40,41 μg.mL-1 para o metileugenol. A presença de matriz e as características intrínsecas da metodologia de HS-SPME requereram uma transformação da curva de calibração. A transformação logarítmica (Log10) foi então aplicada aos dados e os resultados apresentaram homocedasticidade, resíduos dispersos, coeficiente de determinação (r²> 0,99) e recuperação adequados. Estudos de permeação cutânea foram realizados em células de Franz com diferentes quantidades (20, 100 e 200 μL) de óleo essencial de A. canelilla para avaliar o perfil de permeação e retenção em pele de orelha suína e fluido receptor. A análise das amostras nas condições validadas mostrou uma grande permeação e retenção dos compostos na seguinte ordem: fluido receptor >> derme >> epiderme >> estrato córneo. Verificou-se um aumento progressivo e dependência na retenção com base na quantidade aplicada no compartimento doador e grande retenção principalmente no fluido receptor e derme, resultado este compatível com as características físico-químicas de Log P, afinidade ao ambiente hidrofílico e lipofílico, tamanho e peso molecular do 1-nitro-2-feniletano e metileugenol. Em conclusão, o método proposto por HS-SPME-GC-FID para quantificar os compostos majoritários do óleo essencial de A. canelilla em amostras de pele de orelha suína e fluido receptor foi seletivo, preciso, exato e adequado, e pode ser utilizado em análises futuras. / Aniba canelilla (H.B.K.) Mez is an aromatic plant from the Amazon region whose essential oil has 1-nitro-2-phenylethane and methyleugenol as major compounds. Despite of the scientifically proved antifungal and anti-inflammatory activities and the popular use of oil for the treatment of dermatitis, acnes and wounds, there is no study up to date about the quantification of these compounds in skin samples. The aim of this study was the validation of an optimized bioanalytical method by solid phase microextraction on headspace mode in gas chromatograph with flame ionization detector (HS-SPME-GC-FID) for the determination of 1-nitro-2-phenylethane and methyleugenol from the essential oil in different samples of in vitro cutaneous permeation study. A methodology was developed and validated by HS-SPME-GC-FID. The ranges of calibration curves were 2.08 - 207.87 μg.mL-1 for 1-nitro-2-phenylethane and 0.40 - 40.41 μg.mL-1 for methyleugenol. The presence of matrix and the intrinsic characteristics of the HS-SPME methodology required a transformation to the calibration curves. The logarithmic transformation (Log10) was then applied to the data and the results showed homoscedasticity, dispersed residues, and adequate coefficient of determination (r²> 0.99) and recovery. Skin permeation studies were performed on Franz cells with different amounts (20, 100 and 200 μL) of A. canelilla essential oil to evaluate the skin permeation and retention profile in porcine ear skin and receptor fluid. The analysis of the samples under the validated conditions showed a high permeation and retention of the major compounds in the following order: receptor fluid >> dermis >> epidermis >> stratum corneum. A progressive increase and retention dependence were observed based on the amount applied in the donor compartment, and large retention mainly on the receptor fluid and dermis was observed, in accordance with the physicochemical characteristics of Log P, affinity to the hydrophilic and lipophilic environment, size and molecular weight of 1-nitro-2-phenylethane and methyleugenol. In conclusion, the method proposed by HS-SPME-GC-FID to quantify the major compounds of A. canelilla essential oil in porcine ear skin and receptor fluid samples was selective, accurate, precise and adequate, and can be used in future analyzes.
16

Validación de una metodología para la determinación de benceno en suelos mediante HS-GC-FID y su aplicación en biorremediación en suelos co-contaminados con Hg (ii)

Rojas Molina, Nataly Andrea 03 1900 (has links)
Seminario de Título entregado a la Universidad de Chile en cumplimiento parcial de los requisitos para optar al Título de Química Ambiental. / Los suelos se han constituido como el principal sumidero de metales pesados y otros contaminantes producto de causas naturales y actividades antropogénicas. Ejemplo de estas actividades son las mineras que liberan metales pesados, tales como Hg+2, Pb+2, Cu+2 y Zn+2, y las plantas petroquímicas que producen hidrocarburos aromáticos como Benceno, Tolueno, Etilbenceno, y Xilenos (BTEX) a partir de la fracción volátil del petróleo. El objetivo de este seminario de título consiste en validar un método analítico para la cuantificación de benceno en microcosmos conformados por muestras de suelo co-contaminado contenidas en viales, a los cuales se le adiciona una bacteria especializada. De esta forma, se desarrolla una metodología para determinar benceno remanente en suelo, carente de solventes orgánicos, simple y costo-efectiva, mediante un sistema de extracción de espacio de cabeza acoplado a un cromatógrafo de gases junto a un detector de ionización de llama (HS-GC-FID), que permita monitorear la cinética de remoción de benceno en un suelo co-contaminado con Hg (II), durante un proceso de biorremediación bacteriana utilizando la cepa modificada genéticamente Cupriavidus metallidurans MSR33 que es altamente resistente a mercurio. De esta manera, en el presente trabajo se utilizó un suelo contaminado con benceno y mercurio como una aproximación a una situación real de co-contaminación, donde se aplicó una técnica de remediación a través de la utilización de bacterias especializadas capaces de remover benceno en presencia de mercurio. La medición de benceno con la metodología validada permitió monitorear la cinética de biorremediación utilizando la bacteria C. metallidurans MSR33 entregando información rápida y veraz al aplicar directamente en viales con microcosmos de suelo contaminados con Benceno 200 mg×Kg-1 y Hg (II) 2 mg×Kg-1. La determinación de benceno permitió demostrar que este proceso de biorremediación conforma una novedosa tecnología costo-efectiva y amigable con el medioambiente, aplicable a suelos impactados con BTEX en presencia de metales tóxicos. / Soils have been established as the main sink for heavy metals and other pollutants due to natural causes and anthropogenic activities. Examples of these are mining activities which release heavy metals, such as Hg+2, Pb+2, Cu+2 and Zn+2, and petrochemical plants which produce aromatic hydrocarbons such as Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) from volatile fractions of petroleum. The aim of this seminar consists of validate an analytical method for the quantification of benzene in microcosms consisting on vials containing co-contaminated soil samples, which are inoculated with a specially adapted bacterial culture. The methodology was developed in order to measure benzene concentrations remaining in soil in an organic solvent-free, simple and cost-effective manner. This was carried by means of a headspace extraction system coupled to a gas chromatograph with flame ionization detector (HS-GC-FID), that allowed to monitor the kinetics of benzene removal in a soil co-contaminated with Hg (II), during the process of bacterial bioremediation with the genetically modified strain Cupriavidus metallidurans MSR33 that is highly resistant to mercury. Thus, soil samples polluted with benzene and mercury were used on this research as a practical approach to a real co-contamination scenario. A remediation technique was applied by means of bacteria specially adapted to remove benzene from soil in presence of mercury. The measurement of benzene with the validated methodology allowed to monitor the kinetics of bioremediation using the C. metallidurans MSR33 bacterial strain delivering fast and accurate information when applied directly in vials with soil microcosms contaminated with Benzene 200 mg×Kg-1 and Hg (II) 2 mg×Kg-1. The determination of benzene allowed to demonstrate that this process of bioremediation forms a novel, cost-effective and environmental-friendly technology, potentially useful for treatment of soils impacted with BTEX in the presence of toxic metals.
17

Vliv přídavku tuzemských vín při výrobě vinných klobás / The effect of the addition of local wines in the production of wine sausages

Brlíková, Eliška January 2021 (has links)
The aim of this diploma thesis was to determine the effect of the addition of several types of local wines in the production of wine sausages. Selected wine varieties were characterized using basic and modern analytical methods (liquid chromatography with a diode array detector) and the obtained results were compared with the results of sensory analysis.The sensory analysis was divided into two parts, the first evaluated six non-traditional wine varieties used in the production of wine sausages and the second part evaluated samples with the addition of the traditionally used wine variety Veltlínské zelené, but in three different volumes. Using the Statistica program, the data obtained from the sensory analysis were processed and the mutual correlation was evaluated. Using the gas chromatography method with a flame ionization detector the fatty acid content of a standard sample of wine sausage has been determined. Based on all the determined results, the best wine variety for the production of wine sausages was chosen, it was the blue grape variety André.
18

Výroba a charakterizace sýrů s přídavkem rostlinného extraktu / Production and characterization of cheese with the addition of plant extract

Kučerka, Štefan January 2021 (has links)
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.
19

Charakterizace sýrových analogů vyrobených s přídavkem ořechového oleje / Characterization of cheese analogues produced with addition of nut oil

Mitra, Michal January 2020 (has links)
This thesis deals with the production and characterization of cheese analogues, i.e. products where some of the dairy components are partially or completely replaced by a non-dairy component. Model samples – Eidam type cheese and analogue with the addition of pistachio oil, were produced by a conventional technological process at MENDELU in Brno. Free and bound fatty acids, volatile substances and sensory quality were selected and monitored as the main characterizing parameters of the sample quality. The aim was to characterize the differences between the samples caused by the addition of nut oil in the monitored parameters. The HS-SPME-GC-MS method was used for the identification and semi-quantification of volatiles. The extraction of fats from the samples was performed with a mixture of solvents (diethyl ether, petroleum ether), fatty acids were converted to methyl esters by acid esterification with methanolic solution of boron trifluoride as a catalyst and subsequently identified and quantified by GC-FID. Descriptive scales and comparisons with standard were used to sensory evaluate the appearance, color, texture, odor, taste, and overall acceptability of the samples. The structure was monitored by electron microscopy. The results show that the addition of pistachio oil affects the sensory properties, the maturation process (higher content of volatile substances), the nutritional value (increased content of unsaturated fatty acids) and the stability of the product.
20

Analýza vybraných alergenů ve vonných kompozicích / Analysis of selected allergens in fragrances

Koláčková, Adéla January 2010 (has links)
This thesis is focused on potentially allergenic substances (PASs) in cosmetics. Their specific features, methods of control and observation are described. There are also mentioned dermatology problems connected with usage of perfumed cosmetic products in which the allergenic ingredients can be found and possibilities of their regulation. Fragrances are mixtures of natural or synthetic character which give the aroma. In nature, fragrances are produced mainly by plants. More than one hundred fragrances have been identified as allergens. Twenty six of them were declared as PASs. Allergenic components of perfume compositions are the main cause of allergic contact dermatitis. Experimental part of the thesis is focused on the procedure of analysis of specific allergenic fragrances (?-Amylcinnamaldehyde, Anisealcohol, Benzylsalicylate, Cinnamaldehyde, ?-Hexylcinnamaldehyde, 7-Hydroxycitronellal and Methyl-2-octynoate). Headspace-Solid Phase Microextraction connected with Gas Chromatography-Flame Ionisation Detector (HS-SPME-GC-FID) was used for extraction, analysis and identification of these substances. The method was validated and applied on the spectrum of real samples of cosmetic products.

Page generated in 0.0223 seconds