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  • 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.
31

Metodologia alternativa para detecção rápida de Salmonella ssp. em leite via espectroscopia e quimiometria / Determination of Salmonella sp in whole milk by NIR and chemometrics

Pereira, Juliana Marques 06 May 2016 (has links)
CAPES / O leite é um alimento com poder nutricional considerável e, por ser rico em componentes nutritivos, apresenta-se como um ótimo meio de crescimento para microrganismos. Portanto, o leite “cru”, deve passar por um tratamento térmico para reduzir ou eliminar as bactérias nocivas. O consumo de leite que tenha passado por um tratamento inadequado pode levar a infecções devido a diversos agentes patogênicos como, por exemplo, a Salmonella spp.. Por ser altamente nociva, a presença desta bactéria em alimentos é intolerável, tornando obrigatórios os testes microbiológicos de amostras de alimentos para determinar a presença deste microrganismo. Os métodos convencionais para a detecção da Salmonella spp. são lentos e trabalhosos, exigem o uso de volumes consideráveis de meios líquidos e sólidos e reagentes. Desta forma, metodologias alternativas que apresentem vantagens, tais como um custo relativamente baixo, rapidez, não ser destrutiva, ser livre de uso de reagentes, e consequentemente, não gerar Q Residuals, são demandas urgentes no controle de qualidade deste tipo de alimento. Assim, esta pesquisa teve como objetivo oferecer uma metodologia alternativa baseada em Espectroscopia no Infravermelho Próximo (NIR) para discriminar entre presença e ausência de Salmonella spp. em leite integral e desnatado UHT (Ultra High Temperature). Para isso, foram adquiridas diferentes amostras de leite integral e desnatado, ambos tratados de forma UHT. O tratamento dos dados foi realizado em software Matlab®, utilizando-se ferramentas do PLS toolbox®. Os modelos PLS-DA obtidos foram centrados na média, utilizando-se validação cruzada com algoritmo “deixe um fora”. O modelo para a discriminação de amostras de leite desnatado foi construído utilizando-se 4 variáveis latentes e apresentou RMSEC = 0,1639; RMSECV = 0,2084 e RMSEP = 0,0971. Já para leite integral, o modelo foi construído utilizandose 6 variáveis latentes com valores de RMSEC = 0,1351; RMSECV = 0,2076 e RMSEP = 0,0928. Os resultados mostraram que a metodologia sugerida foi capaz de discriminar as amostras contaminadas das não contaminadas com êxito, apresentando potencial para implementação no setor de controle de qualidade deste tipo de alimento. / Milk is a food with significant nutritional value and for being rich in nutritional constituents is presented as a great growth medium for microorganisms. Therefore, the "raw" milk, must undergo a thermal treatment to reduce or eliminate the most harmful bacteria. The consumption of milk that has passed through improper treatment, can lead to infections due to various pathogens such as, Salmonella spp.. For being highly detrimental, the presence of these bacteria in food is intolerable, making the microbiological food testing’sto determine the presence of this microorganism, absolutely required. Conventional methods to detect Salmonella spp. are laborious, requiring the use of significant amounts of liquid and solid media and reagents, besides demanding time-consuming procedures. Therefore, alternative methods which provide advantages, such as, relatively low cost, fast, non-destructive, free of reagents and, consequently, which does not generate waste are urgent demand did to the quality control of this kind of food. Thus, this research aimed to offer an alternative methodology based on Near Infrared (NIR) spectroscopy to discriminate between the presence and absence of Salmonella spp. in whole and skimmed UHT milk. Different samples of whole and skimmed milk, both treated through UHT were submitted to data analysis conducted in Matlab ® software, using PLS toolbox® tools. The PLS-DA models were median centered and cross-validated using leave one out algorithm. The model to discriminate skimmed milk samples was constructed using four latent variables and presented RMSEC = 0.1639; RMSECV = 0.2084 and RMSEP = 0.0971. To the whole milk, the model was built using six latent variables with RMSEC = 0.1351 values; RMSECV = 0.2076 and RMSEP = 0.0928. The results showed that the suggested methodology was able to differentiate between contaminated and uncontaminated samples successfully, presenting potential to be implemented in the quality control sector of milk industry.
32

Efeito do tratamento térmico e da digestibilidade sobre a interação entre aflatoxina B1 e M1 com a fração proteica do leite / Effect of heat treatment and digestibility on interaction between aflatoxin B1 and M1 with the milk protein fraction

Centenaro, Andressa Inez 09 June 2016 (has links)
CNPQ / O leite é uma das principais fontes de nutrientes da dieta humana e é um alimento que acompanha o ser humano durante toda a vida, tanto como leite de consumo como através de seus derivados. O leite pode apresentar contaminação oriunda de diversas fontes, relacionados desde a ordenha até o processo de beneficiamento do mesmo. Dentre esses contaminantes, destacam-se as micotoxinas, que são metabólitos tóxicos produzidos por fungos em condições de estresse. Estudos correlacionam a ocorrência de micotoxinas em leite e derivados lácteos, com ênfase na aflatoxina M1 (AFM1) que é regulamentada pela legislação vigente. Apesar da maior parte da literatura afirmar que a aflatoxina B1 (AFB1) é completamente convertida em AFM1, resultados preliminares tem sugerido que isso não é verdadeiro, o que vem a justificar que a mesma passe, também, a ser analisada, uma vez que a toxicidade da AFB1 é maior que a da AFM1. Na área de leite e derivados lácteos, estudos têm sugerido que as aflatoxinas, em especial a AFM1, localizam-se predominantemente nas frações proteicas. Porém, a elucidação da interação entre AFM1 e fração proteica permanece sem conclusão definitiva, o que sugere um campo amplo de estudo nesta área. Ainda, tendo em vista que a concentração de aflatoxinas é predominante na fração proteica e que pode haver uma interação química entre esta fração e aflatoxinas, os tratamentos térmicos aos quais o leite é submetido podem causar alterações significativas nas estruturas dessas proteínas e, por conseguinte, nas interações entre proteínas e AFM1 e AFB1. Portanto, o entendimento da natureza das ligações entre as AFM1 e AFB1 às proteínas do leite é imprescindível para a compreensão da biodisponibilidade dessas micotoxinas em animais e seres humanos. Desta forma, o objetivo do trabalho foi verificar o efeito do tratamento térmico e da digestibilidade sobre a interação proteína-aflatoxina. Para isso, foram contaminados amostras de solução de caseína bovina e leite desnatado com AFB1 (200 µg.L-1) e AFM1 (20 µg.L-1), posteriormente submetidas a pasteurização e digestão in vitro. As determinações realizadas consistiram na quantificação das AFLB1 e M1 por Cromatografia à Líquido de Ultra Alta Eficiência, Espectroscopia na região do infra vermelho (FTIR), Calorimetria Exploratória Diferencial (DSC) e Espectroscopia de fluorescência. Não houve redução da concentração de AFB1 e AFM1 após o tratamento térmico e a bioacessibilidade foi de 91,2% 70,5% e 90,9% e 69,7%, respetivamente, para caseína bovina e leite desnatado. Avaliando quantitativamente as estruturas secundárias da solução de caseína bovina e leite desnatado contaminados com AFB1 e AFM1 as principais mudanças ocorreram nas estruturas β-volta, β-anti e β-folha. Com a análise de DSC observou-se picos exotérmicos para ambos os ensaios, com variação de entalpia (∆H) após cada ensaio. Em relação aos espectros de fluorescência, foi possível verificar que as AFB1 e AFM1 promoveram redução da fluorescência original das proteínas lácteas. Pelos resultados obtidos, é possível concluir que a concentração das AFB1 e M1 não foram reduzidas pela temperaturaempregada, provavelmente pela interação proteínas do leite-aflatoxina, resultando numa bioacessibilidade relativamente elevada. / Milk and derivates are one of the main sources of nutrients of the human diet and is a food that follow's man during all of your life. The milk may be contaminated from several sources, related since milking until the beneficiation process. Among these contaminants, highlights are the mycotoxins, which are toxic metabolites produced by fungus in conditions of stress. Studies related to the occurrence of mycotoxins in milk and milk products, with the emphasis on aflatoxin M1 (AFM1) which is ruled by Brazilian law. While most of the literature stating that aflatoxin B1 (AFB1) is completely converted into AFM1, preliminary results have suggested that this is not true, justifying that it passes also to analyze because the toxicity of AFB1 is greater than the AFM1. In the milk and dairy products, studies have suggested that aflatoxins, in particular AFM1, are located predominantly in protein fractions. However, the elucidation of the interaction between AFM1 and protein fraction remains without definitive conclusion, suggesting a large broad field of study in this area. Also considering that the concentration of aflatoxins are prevalent in the protein fractions and can have a chemical interaction between these fractions and aflatoxins, the thermal treatments that the milk is subjected can cause significant changes in these proteins structures and consequently in interactions between proteins and AFM1 and AFB1. Therefore, the knowledge of nature of the links between AFM1 and AFB1 to milk proteins is indispensable for understanding the bioavailability of these mycotoxins in animals and humans. Thus, the aim of this study was to investigate the effect of thermal treatment and the digestibility of the interaction protein-aflatoxin. For this, samples of bovine casein solution and skimmed milk were contaminated with AFB1 (200 μg.L-1) and AFM1 (20 μg.L-1), and then submitted to pasteurization and in vitro digestion. The carried analyzes consisted in quantifying AFB1 and AFM1using high performance liquid chromatography, Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and fluorescence spectroscopy. There was no reduction in the concentration of AFB1 and AFM1 and after the thermal treatment the bioaccessibility was 91.2% and 70.5%, 90.9% and 69.7%, respectively, for bovine casein and skim milk. In quantitative assessments of the secondary structures of bovine casein and skim milk contaminated with AFB1 and AFM1 the major changes occurred in the β-turn structures, β-anti and β-sheet. With the DSC analysis was observed exothermic peaks for both tests, the change of enthalpy (∆H) after each test. Regarding the fluorescence spectra, we found that AFB1 and AFM1 promoted reduction of the original fluorescence of milk proteins. From the results, it may be concluded that the concentration of AFB1 and M1 not been reduced by the temperature applied, probably by the interaction between milk protein and aflatoxin, resulting in a relatively high bioaccessibility.
33

Bifenilas policloradas no leite materno brasileiro : desenvolvimento de metodologia analitica e avaliação da contaminação / Polychlorinated biphenyls in the Brazilian breast milk : development of analytical methodology and evaluation of the contamination

Kowalski, Claudia Hoffmann 12 April 2008 (has links)
Orientadores: Helena Teixeira Godoy, Fabio Augusto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-12T13:02:51Z (GMT). No. of bitstreams: 1 Kowalski_ClaudiaHoffmann_D.pdf: 1521730 bytes, checksum: 5077a83f5292bcd2dd1b651ce2fc229c (MD5) Previous issue date: 2008 / Resumo: Um estudo sobre a contaminação do leite materno com bifenilas policloradas (PCB) foi desenvolvido objetivando um conhecimento mais amplo dessa problemática no nosso país. Para isso, amostras de leite foram coletadas em nove estados brasileiros e questionários contendo perguntas sobre hábitos alimentares, condições sócio-econômicas, locais de habitação entre outras foram aplicados às mães doadoras. A determinação dos PCB foi feita por Microextração em Fase Sólida no modo headspace (HS-SPME) combinada com Cromatografia Gasosa e Detector de Captura de Elétrons (GC-ECD). As etapas da SPME foram otimizadas univariadamente e através de planejamento experimental Doehlert. A análise de variância mostrou que a temperatura de extração e a força iônica do meio (estudada através da adição de NaCl) foram as variáveis que mais influenciaram nas quantidades de PCB extraídas. Em seguida, refinaram-se as condições experimentais através de uma abordagem neuro-genética (rede neural Bayesiana aliada a algoritmos genéticos) que identificou como o ponto experimental ótimo a seguinte condição: concentração de NaCl de 0,36 g mL-1, temperatura de extração de 95,0 °C, tempo de extração de 60 minutos e adição de 210 µL de metanol. Após a otimização, o método foi validado através do estudo das figuras de mérito e apresentou-se linear na faixa estudada (1 a 16 µg L-1) com r > 0,9884, além de boa precisão (RSD < 12 %, n = 5), recuperação aceitável (71 a 127 %) e limites de quantificação entre 0,45 µg L-1 e 2,42 µg L-1. A fim de estabelecer correlações entre os resultados das amostras (expressos na forma de áreas cromatográficas) e os resultados obtidos nos questionários, fez-se uso da rede neural de Kohonen. Assim, foi possível verificar que nas cidades metropolitanas o acúmulo de PCB no leite é mais expressivo que em outras regiões. Por exemplo, em São Paulo 58 % das amostras estavam contaminadas com algum PCB, principalmente os congêneres 180 e 153. Outro resultado gerado pela rede foi que, em geral, as amostras de leite maduro (maior porcentagem de gordura) estavam mais contaminadas com PCB. O número de gestações também foi um fator importante a ser considerado, pois o estudo mostrou que o primeiro filho normalmente recebe uma dose maior de PCB do que os demais. Ainda, maior contaminação foi encontrada no leite de mães que moram nas proximidades de indústrias e/ou rios poluídos, corroborando com o fato de que esses compostos chegam facilmente ao meio ambiente e em seguida aos seres humanos / Abstract: A study about the contamination of the breast milk with polychlorinated biphenyls (PCB) was developed aiming a wider knowledge of this problematic in our country. For that, breast milk samples were collected in nine Brazilian states and questionnaires with questions regarding to food habits, social and economic conditions, places of dwelling between others were applied to the donors. The determination of the PCB was done by headspace Solid-Phase Microextraction (HS-SPME) combined with Gas Chromatography and Electron Capture Detector (GC-ECD). The SPME steps were optimized through univariated procedures and Doehlert experimental design. The analysis of variance showed that the temperature of extraction and the ionic strength of the media (studied by the addition of NaCl) were the most significant variables in the quantities of extracted PCB. After that, the experimental conditions were refined considering a neurogenetic approach (Bayesian neural network and genetic algorithms) and it was identified as the optimum experimental point the following condition: concentration of NaCl of 0.36 g mL-1, temperature of extraction of 95.0 °C, time of extraction of 60 minutes and addition of 210 µL of methanol. After the optimization, the method was validated through the study of the figures of merit. It showed linear in the studied range (1 to 16 µg L-1) with r > 0.9884, besides good precision (RSD < 12 %, n = 5), acceptable recuperation (71 to 127 %) and limits of quantization between 0.45 µg L-1 and 2.42 µg L-1. In order to establish correlations between the results of the samples (expressed as chromatographic areas) and the results obtained in the questionnaires, Kohonen neural network had been used. Thus, it was possible to check that in the metropolitan cities the accumulation of PCB in the milk is more expressive than in other regions. For example, in Sao Paulo state, 58 % of the samples were contaminated by some PCB, mainly the congener 180 and 153. Another result produced by the net was that the samples of hindmilk (higher fat percentage) were the most contaminated. The number of gestations also was an important factor to be considered, since the study showed that the first son normally receives a higher dosage of PCB compared to the others. Also higher levels of contamination was found in the milk of mothers who lived in the proximities of industries and/or polluted rivers, corroborating with the fact that these compounds are easily spread in the environment and consequently in the human beings / Doutorado / Doutor em Ciência de Alimentos
34

Isolation and molecular characterization of Bacillus cereus from cow’s raw milk

Lukanji, Zinathi, Ndip, R N January 2015 (has links)
Bacillus cereus is a group of ubiquitous facultative anaerobic spore forming Gram-positive rods commonly found in soil. It has been detected and implicated in several contaminated food products and raw milk in dairy farms and it causes foodborne gastroenteritis by producing several toxins. This study is aimed at characterizing virulence determinants of B. cereus from cow‟s raw milk. A total of 400 raw milk samples were collected in Fort Hare Dairy Trust and Middledrift Dairy Farm; and cultured on Polymyxin pyruvate Egg-Yolk Mannitol Bromothymol Agar (PEMBA) for 48 hours at 37°C. DNA was isolated from the isolates and 16S rDNA was amplified and sent to Central Analytical Laboratory for sequencing. The gyrB gene of B. cereus was also used to confirm the identity of the isolates. Antibiotic susceptibility profiles of the isolates together with virulence genes were investigated. Multilocus Sequence typing was used to investigate the genetic relatedness of some selected isolates. Furthermore, spores of the isolates were produced, harvested and their concentrations determined. All (100%) of the isolates were identified as having a 96-99% similarity to B. cereus, B. thuringiensis and B. anthracis using sequencing; while gyrB gene was observed in all (100%) of the isolates. Three virulence genes nheA, nheB, nheC encoding for non haemolysin enterotoxin were amplified in all (100%) the isolates. All (100%) of the isolates were susceptible to doxycycline, gentamycin, tetracycline, ciprofloxacin, chloramphenicol and streptomycin. Resistance to rifampicin and penicillin G was predominant with equal rate of 100%, while susceptibility to erythromycin, clindamycin and doxycycline ranged from 60% to 100%. The selected isolates were related and are descendants of the same ancestor. All (100%) the isolates produced spores. The B. cereus isolates contain virulence genes, has multiple antibiotic drug resistance and produce spores, which poses a health risk to the public and cannot be used as probiotics.
35

Die ontwikkeling van 'n moniteringsprogram vir roumelkgehalte as deel van die gehaltebestuurstelsel van 'n melkprosesseerder in die Noordwes-provinsie

Linde, Susanna. Gezina. January 2008 (has links)
Thesis (M. Tech.) -- Central University of Technology, Free State, 2008 / In this study, the development and implementation of a quality-monitoring program for raw milk as part of the quality management system of a milk processor was studied. Various aspects that contribute to raw milk quality were also included. Ten factors that are important in the production of good quality raw milk were summarised in the Ten Point Plan for the production of quality raw milk. Thirty-eight producers, who have supplied raw milk to the processor over a period of five year, were involved in this program. The producers are located all over the Northwest Province. Sixty thousand litres of milk is processed at the processor daily. The milk is taken in from the farms on alternative days by tankers supplied by the processor. A mark sheet was developed to evaluate control points during milking that can be measured directly from the laboratory. This was done monthly. Factors that could not be measured in the laboratory were evaluated when visits to the milk parlours were done twice a year. At the end of the year, the results of the mark sheet as well as the results of the parlour audits were compiled on a quality chart and the results were calculated as a percentage. The processor used the results of the quality charts to reward producers for quality milk. It was found that producers do not have the necessary infrastructure and knowledge to analyse milk. Analysing the raw milk and releasing the results to the producer are important measures to identify and manage problem areas that can pose a risk to the production of good quality raw milk. It is very important to supply the producer with the correct and relevant information because most of the representatives of companies, which visit the farms, supply information to the benefit of the product they sell. A formal monitoring program ensures that raw milk adhere to quality measures due to the fact that producers know the basic principles necessary for the production of good quality raw milk and the fact that the producer can implement measures in his/her own unique farm environment. The implementation of the Ten Point Plan for the production of quality raw milk at the processor had a significant influence on the quality of raw milk that was bought from producers. During times of milk shortages, the processor had to buy milk from alternative sources, which have no quality-monitoring program. Most of the times, this milk did not comply with the law regarding the total bacterial count, the coliform count, and the E. coli count. Record keeping is an important part of the management system of a dairy. Results from this study stressed a meaningful relationship between the keeping of records as mentioned in the Ten Point Plan and the production of good quality raw milk. It is recommended that producers be sharpened regarding the requirements for the production of good quality raw milk. Purchasing good quality raw milk assured the marketing of the best quality dairy products to the consumer. The contribution of this study to the dairy industry is the fact that the implementation of a quality-monitoring program ensures the maintenance of a sustainable quality of raw milk to the industry.
36

Toxic elements in foodchain : exposure pathways to infants in selected areas of Limpopo Province

Ali, Y.D. (Yemisi Deborah) 07 1900 (has links)
This study was concerned with establishing the extent to which various components of the environment were exposed to the three toxic minerals, arsenic, mercury and lead. The concentration of these three elements were determined in groundwater and surface water, soil, plants, animals such as goats, and humans in potentially contaminated areas in the Limpopo Province of South Africa. The focus of the study was to assess the possible exposure to infants through ingestion to arsenic, mercury and lead. Comparison of the mineral content of water at the study sites with international and national drinking water standards, indicated water from Rooiberg, Leeupoort and Gravelotte are not fit for human consumption due to high arsenic and lead concentrations. Water at Gravelotte also has unacceptably high levels of mercury. The soil, plants, goat’s milk and mother’s milk at Rooiberg have higher levels of arsenic and lead than have been recorded for many other countries. Mother’s milk and goat’s milk are the main sources of arsenic, lead and mercury contamination at Rooiberg. It is therefore newborns and toddlers who are most at risk from exposure to arsenic and lead. This is a cause for environmental and health concerns, but as this research is only a base-line study, it is imperative that more comprehensive surveys of potentially toxic mineral contamination be conducted in the province. / Environmental Sciences / (M.Sc. (Environmental Science))
37

Toxic elements in foodchain : exposure pathways to infants in selected areas of Limpopo Province

Ali, Y.D. (Yemisi Deborah) 07 1900 (has links)
This study was concerned with establishing the extent to which various components of the environment were exposed to the three toxic minerals, arsenic, mercury and lead. The concentration of these three elements were determined in groundwater and surface water, soil, plants, animals such as goats, and humans in potentially contaminated areas in the Limpopo Province of South Africa. The focus of the study was to assess the possible exposure to infants through ingestion to arsenic, mercury and lead. Comparison of the mineral content of water at the study sites with international and national drinking water standards, indicated water from Rooiberg, Leeupoort and Gravelotte are not fit for human consumption due to high arsenic and lead concentrations. Water at Gravelotte also has unacceptably high levels of mercury. The soil, plants, goat’s milk and mother’s milk at Rooiberg have higher levels of arsenic and lead than have been recorded for many other countries. Mother’s milk and goat’s milk are the main sources of arsenic, lead and mercury contamination at Rooiberg. It is therefore newborns and toddlers who are most at risk from exposure to arsenic and lead. This is a cause for environmental and health concerns, but as this research is only a base-line study, it is imperative that more comprehensive surveys of potentially toxic mineral contamination be conducted in the province. / Environmental Sciences / (M.Sc. (Environmental Science))
38

The management and control of milk hygiene in the informal sector by environmental health services in South Africa

Agenbag, Michael Hermanus Albertus January 2008 (has links)
Thesis (M. Tech.) -- Central University of Technology, Free State, 2008 / Local government (LG) is under increasing pressure from the milk industry and consumers regarding their ability and willingness to carry out their mandate with regard to the quality control of milk, especially in the informal sector. The government and the milk industry currently have programmes underway to stimulate economic activities in the informal sector, targeting emerging cattle farmers for the production of milk as part of government’s Accelerated Shared Growth Initiative of South Africa (ASGISA). These initiatives further increase the number of informal milk producers and distributors, which holds a further challenge to regulatory authorities. At the same time, the quality of milk from the informal milk-producing sector poses a serious public health concern. Most of the milk produced and sold by the informal sector is raw (unpasteurised), which does not meet the minimum statutory requirements, and the milking practices applied by the informal sector also do not comply with best practice compliance standards. Local authorities (LAs) are statutorily responsible for registering milking parlours and controlling milk hygiene quality from production stage to purchase stage in order to ensure safe and wholesome dairy products to the consumer. Therefore, LG should play an increasingly important role in ensuring that safe and wholesome milk is produced and distributed to the consumers. All metropolitan municipalities (metros) and district municipalities (DMs) should be authorised by the Ministry of Health to enforce the Foodstuffs, Cosmetics and Disinfectants Act, 1972 (Act 54 of 1972) through their authorised officials – mainly environmental health practitioners (EHPs). Secondly, LG should have specific programmes, systems and resources to register, monitor, evaluate and control milk production and distribution outlets for continued compliance
39

Avaliação de resíduos de oxitetraciclina em leite de vacas acometidas de dermatite digital papilomatosa tratadas por aplicação tópica e intramuscular / Milk oxitetracicline residues evaluation in DDP afflicted cows treated with topic and intramuscular administration

Oliveira, Marcus William Mauricio de 02 February 2006 (has links)
O presente trabalho visa avaliar a presença de resíduos de oxitetraciclina de longa ação em leite de vacas acometidas de dermatite digital papilomatosa, divididas em dois grupos, tratadas por aplicação tópica e intramuscular, utilizando a técnica de Cromatografia Líquida de Alta Eficiência. Desta forma, objetivando determinar a curva de eliminação da oxitetraciclina de longa ação em múltiplas administr ações e o período de carência desse antibiótico no leite, foram colhidas amostras biológicas em diferentes tempos após a administração do fármaco. O método analítico validado apresentou linearidade, limite de quantificação, recuperação, precisão e exatidão adequados, para a quantificação da oxitetraciclina em leite bovino. Os animais do grupo 2, tratados com a aplicação tópica, não apresentaram resíduos no leite. No grupo 1, onde os animais foram tratados com aplicação intramuscular, o aumento na concentração do resíduo variou de acordo com a proximidade da coleta com a administração, e foram tão altos quanto 4854ng/ml, e os limites máximos de resíduos, foram superiores a tempo de carência preconizado pelos laboratórios farmacêuticos. / The purpose of this present work is to evaluate the presence of long action oxitetracic1ine residues in milk from DDP afflicted cows, treated with topic and intramuscular administration (8 animals per group). Analysis were performed by High Performance Liquid Chromatography after treatment with trichloracetic acid. Therefore, aiming to determine the long action oxitetracic1ine elimination curve in milk residues, after multiple administrations, and withdraw period, biological samples were collected in different times after antibiotic administrations. The validated analytic method showed suitable linearity, quantification limit, accuracy, precision and recovery, for quantification of oxitetraciclina in milk. The group in which oxytetracycline, was administred dermically showed any residues in milk in all analysed samples. In the first group, where the animals were treated with intramuscular administration, values as high as 4854 ng/ml were detected, and concentration were higher than Maximum Residue Levels after the withdraw period, determined for the pharmaceutical laboratories.
40

Avaliação de resíduos de oxitetraciclina em leite de vacas acometidas de dermatite digital papilomatosa tratadas por aplicação tópica e intramuscular / Milk oxitetracicline residues evaluation in DDP afflicted cows treated with topic and intramuscular administration

Marcus William Mauricio de Oliveira 02 February 2006 (has links)
O presente trabalho visa avaliar a presença de resíduos de oxitetraciclina de longa ação em leite de vacas acometidas de dermatite digital papilomatosa, divididas em dois grupos, tratadas por aplicação tópica e intramuscular, utilizando a técnica de Cromatografia Líquida de Alta Eficiência. Desta forma, objetivando determinar a curva de eliminação da oxitetraciclina de longa ação em múltiplas administr ações e o período de carência desse antibiótico no leite, foram colhidas amostras biológicas em diferentes tempos após a administração do fármaco. O método analítico validado apresentou linearidade, limite de quantificação, recuperação, precisão e exatidão adequados, para a quantificação da oxitetraciclina em leite bovino. Os animais do grupo 2, tratados com a aplicação tópica, não apresentaram resíduos no leite. No grupo 1, onde os animais foram tratados com aplicação intramuscular, o aumento na concentração do resíduo variou de acordo com a proximidade da coleta com a administração, e foram tão altos quanto 4854ng/ml, e os limites máximos de resíduos, foram superiores a tempo de carência preconizado pelos laboratórios farmacêuticos. / The purpose of this present work is to evaluate the presence of long action oxitetracic1ine residues in milk from DDP afflicted cows, treated with topic and intramuscular administration (8 animals per group). Analysis were performed by High Performance Liquid Chromatography after treatment with trichloracetic acid. Therefore, aiming to determine the long action oxitetracic1ine elimination curve in milk residues, after multiple administrations, and withdraw period, biological samples were collected in different times after antibiotic administrations. The validated analytic method showed suitable linearity, quantification limit, accuracy, precision and recovery, for quantification of oxitetraciclina in milk. The group in which oxytetracycline, was administred dermically showed any residues in milk in all analysed samples. In the first group, where the animals were treated with intramuscular administration, values as high as 4854 ng/ml were detected, and concentration were higher than Maximum Residue Levels after the withdraw period, determined for the pharmaceutical laboratories.

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