Orientador: Manoel Lima de Menezes / Banca: Célia Maria de Sylos / Banca: Myrna Sabino / Banca: Maria Lucia Ribeiro / Banca: Helena Teixeira Godoy / Resumo: As investigações sobre a incidência de micotoxinas em alimentos são de suma importância para que esforços possam ser concentrados na prevenção, controle e na destoxificação dos produtos susceptíveis a esse tipo de contaminação. Dentre as micotoxinas existentes, a ocratoxina A, produzida por Aspergillus ochraceus, e Penicillium verrucosum é nefrotóxica, e o seu alvo secundário é o fígado. Esta micotoxina, que também apresenta atividade fortemente teratogênica em animais de laboratórios, tem sido encontrada em baixas concentrações em amostras de milho, soja, trigo, cevada, arroz, sorgo e amendoim. O brasileiro consome em média 46,8 litros de cerveja por ano, e esta tem como matéria-prima principal cevada, além de coadjuvantes como o milho e o arroz. Considerando-se que vários métodos analíticos, relatados na literatura, para a determinação das ocratoxinas A e B em diferentes tipos de amostras, sobretudo em bebidas, requerem o pré-tratamento da amostra (clean up) ou o emprego de colunas de imunoafinidade, foi desenvolvido um novo método analítico, por injeção direta da amostra de cerveja, empregando cromatografia líquida de alta eficiência, com uma coluna cromatográfica aniônica-ISRP (Internal Surface Reverse Phase). Assim foi possível efetuar a extração e pré-concentração on line da ocratoxina A (OTA) e ocratoxina B (OTB) presentes em amostras reais de cervejas. Os resultados obtidos indicaram que o método proposto é eficiente para a detecção e quantificação de OTA e OTB em cervejas. A avaliação da ocorrência destas ocratoxinas em cervejas comercializadas em Bauru e região mostraram que 7,1 % das amostras de cervejas nacionais, num total de 42 amostras, e 11,0 % das cervejas importadas num total de 09 amostras, estavam contaminadas com OTA. A OTB não foi detectada nas amostras de cervejas importadas. / Abstract: The investigations on the incidence of mycotoxins in food are crucial in order that the effords can be concentrated on prevention, control, and on the de-toxication of the products susceptible to this kind of contamination. Among the existent mycotoxins, the ochratoxins A, produced by Aspergillus ochraceus, Penicillium verrucosum and Peniciliumnomis, is nephrotoxic, and its secundary target is the liver. This mycotoxin, which also presents an activity strongly teratogenic in laboratory animals, has been found, in low concentrations, in corn, soy, wheat, barley, rice, sorghum, and peanuts samples. Brasilian people have an average ingestion of 4.8 litters of beer yearly, and beer, has as the main raw material, barley, besides corn and rice. Considering that various analytical methods reported in the literature for determining the ochratoxins A and B, in different types of samples, particularly in alcoholic beverages, require the pretreatment [clean-up] of the sample or the immunoaffinity columns,this present study proposed the development of a new analytic method, by direct injection of the beer sample, employing the high efficiency liquid chromatography, with an anionic chromatographic column ISRP(Internal Surface Reverse Phase), which possibilitate to carry out the extraction and pre-concentration on line of the Ochratoxin A (OTA) and Ochratoxin B (OTB) present in real beer samples, without the presence of interferent peaks. This study results indicated that the proposed method is effective for detection and quantitification OTA and OTB in beers. The survey of these ochratoxins occurrence in beers marketed in Bauru, and region (Sao Paulo State, Brazil), showed that 7.1% of the ochratoxins of national beers and 11.0% of the imported beers were contaminated by OTA. OTB was not detected in imported beers samples. / Doutor

Maneiras de se produzir hidrogênio limpo e combustíveis alternativos para uso em células a combustível têm sido um dos grandes desafios na busca por fontes de energia limpas e renováveis. Recentemente, foi desenvolvido em nosso laboratório um sistema em que o etanol é desidrogenado em um reator acoplado à uma célula a combustível de troca protônica (PEMFC) e o hidrogênio resultante dessa reação foi utilizado como combustível. No entanto, houve uma perda de densidade de potência da célula que, em 0,7 V, foi de 40% em relação à de uma célula alimentada com hidrogênio puro. O motivo dessa perda de desempenho ainda não foi elucidado, sendo este o foco do estudo realizado neste trabalho. Pesquisas sobre a contaminação de células PEM por várias impurezas, como por exemplo, CO, metanol, ácido fórmico, etc., já têm sido realizadas, mas, até o momento, nenhum estudo foi encontrado sobre a influência dos subprodutos da reação de desidrogenação do etanol (acetato de etila, acetaldeído e etanol não reagido) no desempenho destes sistemas. Além disso, devido à ausência de CO2, o hidrogênio produzido teria grande potencial para ser utilizado em células de membrana de troca aniônica (AEMFC) e, portanto, a realização de estudos sobre a influência desses contaminadores sobre o desempenho desse tipo de célula também é altamente relevante. Diante disso, neste trabalho, desenvolveu-se uma nova vertente de pesquisa, onde o hidrogênio foi contaminado pelos subprodutos em questão e as influências destes contaminadores sobre os desempenhos das PEMFC e AEMFC foram estudadas. No caso da AEMFC, por não haver membranas e, especialmente, ionômeros comerciais que resultem em células com altas densidades de potência, buscou-se sintetizar esses materiais antes dos estudos das contaminações. Através da análise por diferentes técnicas, foi possível esclarecer que o etanol não reagido é o principal veneno no caso das PEMFCs, sendo que o acetaldeído e o acetato de etila têm contribuições menores para o envenenamento. Foram testados diferentes eletrocatalisadores nos eletrodos a fim de se obter melhores desempenhos, sendo que o melhor resultado foi observado quando se utilizou o catalisador de Pt-Co/C no cátodo da célula (e Pt/C no ânodo), sendo que em 0,7 V a perda em densidade de potência foi de apenas 20% em comparação à uma célula alimentada por H2 puro e com Pt/C ambos os eletrodos. No caso da AEMFC, foi possível se obter ionômeros inéditos que combinados com as membranas sintetizadas, resultaram em células com densidade de potência máxima acima de 1 W cm-2. No entanto, devido à instabilidade química, ao serem expostos aos contaminadores, os materiais parecem sofrer degradação, que leva à perda quase total e irreversível do desempenho da célula. / The development of methods to produce clean hydrogen and alternative fuels for fuel cells has been a big challenge in the search of clean and renewable electric energy sources. Recently, a system was developed in our laboratory where ethanol was dehydrogenated in a reactor coupled to a proton exchange membrane fuel cell (PEMFC) and the hydrogen produced from this reaction was used as fuel. However, a loss of 40% in power density of the cell was observed at 0.7 V when compared to a cell fed with pure hydrogen. The reason for this loss of performance was not elucidated and this is a focus of the study involved in this work. Researches on the effect of contamination of PEM cells by various impurities, such as CO, methanol, formic acid, etc., have already been made, but so far, nothing has been found about the influence of the byproducts of the ethanol dehydrogenation reaction (ethyl acetate, acetaldehyde and unreacted ethanol) in fuel cells performances. Moreover, because of the absence of CO2, the hydrogen produced in such dehydrogenation reactor could have a great potential for applications in anion exchange membrane fuel cells (AEMFC), making the characterization of the influence of these contaminants in the performance of such systems of high relevance. In this context, in this work a new research strand was developed, where hydrogen was contaminated by the by-products of the ethanol dehydrogenation and their influences on the performances of PEMFC and AEMFC were investigated. In the case of AEMFC, because of the lack of commercially available membranes and ionomers that lead to high power densities, it was necessary to synthesize these materials before the contamination studies. Through the analysis by different techniques, it was possible to clarify that unreacted ethanol is the main poison in the case of PEMFCs, with acetaldehyde and ethyl acetate having minor contributions. Different catalysts were tested in order to obtain better fuel cells performances and the best result was achieved when the Pt-Co/C catalyst was used at the cathode of the cell (with Pt/C at the anode), for which the loss of power density was only 20% compared to a cell fed by pure H2 and with Pt/C on both electrodes (working at 0.7 V). In the case of the AEMFC, new ionomers were obtained that combined with the synthesized membranes resulted in cells with a maximum power density above 1 W cm-2. However, due to the chemical instability, when exposed to contaminants, these materials appear to undergo degradation, leading to almost total and irreversible losses of the cell performance.

A deposição de aflatoxinas em peixes é residual e cumulativa, além de causar efeitos adversos no peso, tamanho, consumo de ração e sobrevivência, demarcando amplas diferenças quanto à sensibilidade e metabolismo entre as espécies. O presente trabalho teve como objetivo avaliar a transferência de aflatoxinas da ração para matrinxã (Brycon cephalus) e a influência sobre parâmetros biométricos, bioquímicos e histopatológicos. As aflatoxinas foram incorporadas na ração pelo método de imersão em metanol, obtendo-se os seguintes tratamentos: A. Controle - ração sem toxina; B. Ração + 10 &micro;g Aflatoxina B1/kg; C. Ração + 20 &micro;g Aflatoxina B1/kg e D. Ração + 50 &micro;g Aflatoxina B1/kg. As aflatoxinas foram quantificadas por cromatografia líquida de alta eficiência (CLAE) no fígado e músculo de matrinxã. Para avaliação do desempenho produtivo foram mensurados o peso, comprimento, taxa de sobrevivência e consumo diário de ração. Para avaliação bioquímica e histopatológica foram realizadas coletas de sangue por punção da veia caudal para determinação das atividades séricas de aspartato aminotransferase (AST), fosfatase alcalina (FA), proteínas totais (PT), albumina (ALB) e globulina (GLOB). Para observação histológica foram coletados fragmentos de fígado, que foram processados para posterior inclusão em parafina e coloração de hematoxilina e eosina. Os peixes expostos aos tratamentos B, C e D apresentaram menor peso e comprimento (P<0,05) quando comparados com o tratamento controle, sendo os matrinxãs do tratamento C os mais afetados. O consumo de ração e a sobrevivência apresentaram diferenças a partir do dia 150 no tratamento D. Foi observado o acúmulo de AFB1 no fígado em função do aumento da concentração da toxina na ração. No tratamento D, foram observados resíduos a partir do dia 30, com valores entre 0,17 e 0,62 mg AFB1/kg. AST, FA, PT, ALB e GLOB, apresentaram alterações muito discretas, o que dificultou a identificação de danos hepáticos ou afecções à funcionalidade do fígado. A exposição à AFB1 causou degeneração gordurosa moderada e severa, degeneração hidrópica, morte celular ou células em processo de morte e desorganização do arranjo cordonal. Conclui-se que matrinxã sob condições experimentais não representa risco à saúde do consumidor, no entanto, é uma espécie sensível aos efeitos adversos das aflatoxinas. / The deposition of aflatoxins in fish is residual and cumulative, besides causing adverse nonlethal effects on weight, size, feed consumption and survival, establishing wide differences in sensitivity and metabolism among species. The present work aims to evaluate the transfer of aflatoxins from the feed to matrinxã (Brycon cephalus) and the influence on biometric, biochemical and histopathological parameters. The aflatoxins were incorporated into the feed by the method of immersion in methanol, obtaining the following treatments: A. Control - feed without toxin; B. Feed + 10 &micro;g AFB1/kg; C. Feed + 20 &micro;g AFB1/kg and D. Feed + 50 &micro;g AFB1/kg. Aflatoxins were quantified by high performance liquid chromatography (HPLC) in the liver and muscle of matrinxã. performance based on weight, length, survival rate and daily feed intake was evaluated. Blood samples were collected to determine the serum activity of aspartate aminotransferase (AST), alkaline phosphatase (AP), total proteins (PT), albumin (ALB) and globulin (GLOB). For histological observation, liver fragments were collected and processed in paraffin followed by hematoxylin and eosin staining. The fish exposed to treatments B, C and D presented lower weight and length (P<0.05) when compared with the control treatment, and the matrinxãs of treatment C were the most affected. Feed intake and survival showed differences from day 150 in treatment D. AFB1 accumulation was observed in the liver as the toxin concentration in the diet increased. In treatment D, residues were observed from day 30 with values between 0.17 and 0.62 mg AFB1/kg. AST, AF, PT, ALB and GLOB presented very discrete alterations, making it difficult to identify liver damage or liver function disorders. Exposure to AFB1 caused moderate and severe fatty degeneration, hydropic degeneration, cell death or cells in the process of death and disorganization of the cordial arrangement. Concludes that matrinxã under experimental conditions does not pose a risk to consumer health, however, is a susceptible species to the adverse effects of aflatoxins.

L'ulcère de Buruli, maladie négligée, pouvant entraîner déformations et incapacités permanentes, causée par Mycobacterium ulcerans, une mycobactérie associée aux écosystèmes aquatiques. Les sources et réservoirs de M. ulcerans ne sont pas précisément connus limitant la prophylaxie. Ma thèse contribue à démasquer les sources de contamination par M. ulcerans. Ma revue de la littérature répertoriant les sources potentielles, met en exergue les pièces manquantes pour la compréhension de l’épidémiologie de l’ulcère de Buruli. Mon étude de coculture M. ulcerans-Acanthamoeba griffini indique que cette amibe n’est pas un réservoir de M. ulcerans. Ensuite, mon étude du métabolisme des substrats carbonés indique que les bactéries, champignons, algues et mollusques peuvent combiner des sources carbonées au profit de M. ulcerans dans l’environnement. Capitalisant sur ce résultat, mon étude de l’effet des mycolactones secrétées par M. ulcerans sur les champignons, montre une attraction sur Mucor circinelloides. Ces observations démasquent une nouvelle activité de la mycolactone d’attraction d’organismes fungiques. Le mode de transmission de M. ulcerans à l’homme reste également un mystère. Dans ce sens, j’ai détecté des séquences d'ADN spécifiques de M. ulcerans sur la peau saine d’individus asymptomatiques en zones d’endémie. Ces données pourraient aider à promouvoir une prophylaxie fondée sur le port des habits de protection au contact des environnements à risques. En perspective à mon travail de thèse, une collaboration est mise en place avec le PNLUB et l’Institut Pasteur de Côte d’Ivoire pour étudier les réservoirs de M. ulcerans en Côte d'Ivoire. / Buruli ulcer is a dermis, epidermis and sometimes bone infection leading to deformities and permanent disabilities. It is caused by Mycobacterium ulcerans, a mycobacterium associated to the aquatic ecosystems but its sources and reservoirs are not yet defined. Therefore, no prophylaxis is established. This thesis contribute to unmask the sources of contamination of M. ulcerans. My review has identified potential sources of M. ulcerans in the environment and highlighted the missing pieces for understanding the epidemiology of Buruli ulcer. My study on the role of amoeba in the survival of M. ulcerans in the environment, install M. ulcerans as susceptible to amoeba rendering amoeba an unlikely host of M. ulcerans. Hereafter, i studied carbon substrates metabolized by M. ulcerans strains. Literature survey indicated that the environmental sources of carbon substrates metabolized by M. ulcerans were bacteria, fungi, algae and mollusks. I therefore studied the interactions of M. ulcerans with fungi by testing the effect of mycolactones on fungi. Mycolactones showed an attraction effect on Mucor circinelloides. This observation suggest a novel role for mycolactones as chemoatractants to fungi. The mode of transmission of M. ulcerans to humans remains unknown. I showed that M. ulcerans DNA can be detected on the healthy skin of asymptomatic persons, suggesting an asymptomatic carriage. These data could help promote prophylaxis based on wearing protective clothing in contact with risky environments. In perspective to my thesis work, we set up a collaboration with the Buruli Ulcer Program (PNLUB) and Institut Pasteur Côte d'Ivoire to study the reservoirs of M. ulcerans.

Uma área contaminada à jusante do Aterro de resíduos sólidos urbanos de Bauru foi investigada através dos métodos Eletroresistividade e Polarização Induzida, com uma técnica de imageamento 3D. O conjunto de dados 3D foi formado por dados de uma série de caminhamentos elétricos paralelos realizados com o arranjo dipolo-dipolo, e foi invertido como um levantamento 3D. Os resultados dos modelos invertidos de resistividade e cargabilidade sugerem a presença de uma pluma contaminação e seu caminho preferencial, que segue o sentido do fluxo subterrâneo. Dados de análises químicas das águas de poços de monitoramento comprovam a contaminação incipiente. / A contaminated site downstream a landfill in Brazil was investigated using a 3D resistivity and induced polarization imaging technique. The data set consisted of a series of parallel electrical profile data acquired with the dipole-dipole array, and was inverted as a 3D survey. . The results suggest the presence of a contamination plume and their preferential path, which is in good agreement with the underground water flow data. Chemical analysis data from the monitoring wells confirm the incipient contamination.

O presente estudo foi dividido em duas fases; a primeira visou avaliar o desempenho de diversos meios de cultura, para fungos, no ar de ambientes de produção de alimentos, através da resposta de contagem e identificação dos gêneros que podem conter espécies indesejáveis; também foi avaliada a condição ambiental juntamente com a contagem total de bactérias. O ambiente de duas áreas foi utilizado para a pesquisa, uma indústria de doces, produção de doce de leite e doce de amendoim, na Cidade de Ribeirão Preto (SP) e, outra, uma indústria de embutidos, nos setores de empacotamento e produção, na Região de Piracicaba (SP). Os meios de cultura utilizados foram: "ichloran Rose Bengal Chloramphenicol Ágar" RBC), "Sabouraud Dextrose a 4% Ágar", "Malt Ágar" (MA), "Malt Extract Agar - Yeast and Molds" (MEAYM), "Plate Count Ágar-Cloranfenicol" (PCA-Cloranfenicol), "Dichloran 18% Glycerol Ágar" (DG 18), Batata Dextrose Ágar (BDA) e "Oxytetracycline Glucose YeastAgar" (OGY); para a contagem de bactérias foi utilizado o meio "Plate Count Agar" (PCA). Cada um dos pontos foi amostrado em triplicata utilizando um amostrador de impactação linear. A segunda fase do projeto avaliou os meios de cultura "Dichloran Rose Bengal Chloramphenicol Ágar" (DRBC), "Sabouraud Dextrose a 4% Ágar" selecionados da primeira fase. Novas coletas foram realizadas amostrando cinco repetições em cada um dos pontos, que permaneceram os mesmos da primeira fase. Em paralelo foram utilizadas culturas puras de Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus parasiticus, Fusarium moniliforme, Fusarium verticulloides, Histoplasma capsulatum e Stachybotrys chartarum, inoculando os dois meios selecionados e avaliando o desenvolvimento desses fungos ao longo do período de incubação de sete dias, a 28ºC, para servir de parâmetro de comparação com as coletas de ar realizadas no mesmo período, a fim de se verificar se algum desses fungos indesejáveis estaria presente nas amostras de ar. De acordo com os resultados obtidos, os meios DRBC e Sabouraud Dextrose a 4% Ágar, foram, estatisticamente, melhores que os demais meios testados, apresentando um maior número de unidades formadoras de colônias/m3. O meio de Extrato de Malte diferenciou estatisticamente dos demais e teve o menor desempenho para a quantificação desses microrganismos no ar. A recomendação do melhor meio para identificação de fungos no ar de indústrias alimentícias não foi conclusiva, com exceção do PCA-Cloranfenicol que apresentou baixa diversidade de gêneros, sendo considerado reprovado. No geral foi observado um número elevado de unidades formadoras de colônias de fungos e bactérias/m 3 durante as amostragens. A avaliação quali-quantitativa dos ambientes estudados sugere que esses não se encontram em condições adequadas, sendo necessária a elaboração de um padrão referencial para o monitoramento da indústria alimentícia em nosso país. O amostrador utilizado nas coletas promoveu rapidez nas coletas e proporcionou a expressão dos resultados em medidas confiáveis, por ser um equipamento que permite calibração em seu sistema de aspiração de ar. / The present study consisted of two phases. The first one aimed at evaluating the performance of different culture media for fungi found in the air of food production environments, through the results of counting and identifying genders that may contain undesirable species. The environmental condition was also evaluated along with a total bacteria counting. The present work took place in two different places, an industry which produces sweets made from milk or peanuts, in Ribeirao Preto city (SP) and, in the packing and production sections of a meat encased products industry located in Piracicaba region (SP). The culture media used were: "Dichloran Rose Bengal Chloramphenicol Agar (DRBC)", "Sabouraud Dextrose 4% Agar (MA)", "Malt Extract Agar - Yeast and Molds (MEAYM)", "Plate Count Agar - Chloramphenicol (PCA-Chloramphenicol)", "Dichloran 18% Glycerol Agar (DG 18)", "Potato Dextrose Agar (BDA)" and "Oxytetracycline Glucose Yeast Agar (OGY)". The medium used for the bacteria counting was "Plate Count Agar (PCA)". Three replicates of each sampled spot were obtained by using a linear impacting sampler. The second phase of this project evaluated the following culture media, selected during the first phase of this study: "Dichloran Rose Bengal Chloramphenicol Agar (DRBC)" and "Sabouraud Dextrose 4% Agar". New sample collections (five replicates) were carried out for each of the spots selected. The sampled spots were the same for both phases. In a parallel manner, pure cultures of Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus parasiticus, Fusarium moniliforme, Fusarium verticulloides, Histoplasma capsulatum and Stachybotrys chartarum were employed to inoculate the two selected media. The development of these fungi was evaluated throughout a 7-day-incubation period, at 28ºC, to function as a comparative reference for the air samples obtained in the same period in order to verify if any of these undesirable fungi was present in the air samples. According to the results obtained, DRBC and Sabouraud Dextrose 4% Agar media were statistically superior than the others, presenting a higher number of colony forming units/m3. The Malt Extract medium was statistically different from the others and showed the worse performance as to the quantification of microorganisms present in the air. There was no conclusive recommendation as to the best medium for the identification of fungi found in the air of food industries, except for PCA-Chloramphenicol, which showed low diversity of genders and was discarded. In general, a high number of fungi and bacteria colony forming units/m3 was observed during the sampling procedures. The qualitative-quantitative evaluation of the environments studied suggests that they do not present adequate conditions, evidencing the need for the establishment of a referential standard in order to monitor food industries in our country. The sampler used in this work allowed a quick sample collection and a reliable expression of results, as this equipment enables the calibration of its air intake system.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Chemistry in the Faculty of Applied Sciences at the Cape Peninsula University of Technology / Paperboard made from recycled fibres is being used more frequently in direct food packaging applications, in addition to its use as secondary and tertiary packaging. However, recent research has shown that there is a risk that harmful chemicals may migrate from the paperboard into the food. The simplest approach to reducing the migration of these contaminants is the use of barrier films. The barrier efficiencies of these various films can be examined by means of a migration test into a food simulant, followed by extraction in a suitable solvent. The extract can then be analysed by chromatographic techniques such as gas chromatography mass spectrometry (GC-MS) to determine the concentration of the specific contaminants. However on a production level, the availability of this type of highly specialised equipment is limited. A simple, cost effective method is needed to evaluate the barrier properties to specific chemical contaminants. The Heptane Vapour Transmission Rate (HVTR) test is a permeation test method for use at quality control level to determine barrier properties to the migration of organic vapours. The first part of the study focussed on establishing a universal correlation between HVTR and specific migration of diisobutyl phthalate (DiBP), dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP) that would be applicable to any type of functional barrier. However, experimental data demonstrated this was not possible as the correlation factor linking HVTR to specific migration was largely dependent on the type and morphology of the coating considered. The initial objective of the study was reconsidered in favour of building individual models specific to the nature of the coating and substrate considered. A correlation between HVTR and specific migration of DiBP, DBP and DEHP for a polyvinylidene chloride (PVDC) barrier polymer was constructed by varying the applied coating weight. The vapour transport mechanism for the HVTR test and the specific migration test were found to differ, showing that a direct correlation between HVTR and the specific migration was again not possible. However, an indirect correlation could be made. The HVTR method gives an indication of film integrity, whereas the coating weight could be used as an indicator of the specific migration. The correlation between the coating weight and the specific migration yielded an equation that can be used to calculate the specific migration through the PVDC barrier polymer, provided the quantity of the chemical contaminant originally present in the paperboard was known. This equation was specific to the type of barrier polymer, the specific chemical contaminant as well as the intended shelf-life of the food product to be packaged in the paperboard.

Dissertation submitted in fulfilment of the requirements for the degree Master of Technology: Environmental Health in the Faculty of Applied Sciences at the Cape Peninsula University of Technology, 2011 / The retail sector in South Africa is increasingly evolving into a dynamic industry, driven by changes in technology, saturating markets and globalisation. A major phenomenon in South Africa has been the evolution of hypermarkets, which sell large quantities of almost all consumer goods on a self-service basis. The South African consumers are becoming increasingly health conscious and, as such, the demand for wellness foods, health and convenience food has escalated. Convenience foods are expected to remain popular with consumers and supermarkets and will therefore increase the amount of ready-to-eat food items offered. As the retail industry has changed over the last two decades, so has the epidemiology of foodborne illnesses, with an increase in the incidence of bacterial infections caused by emerging organisms. In addition, there are certain food safety issues specifically associated with ready-to-eat foods. In recent years, incidences of enteric diseases associated with meat consumption have risen. The emergence of several new foodborne diseases has led to an increased focus attention on the issue of food safety by consumers and the industry. The most commonly implicated foods in these disease outbreaks have been meat and dairy products. The microbial load of eight convenience food manufacturing plants was determined by firstly sampling stainless steel food contact surfaces after they had been cleaned and sanitised at the end of a day‘s shift. The samples were analysed for Total Plate Count (TPC), Escherichia coli, Salmonella species and Staphylococcus aureus and Listeria. The results showed that 59 % of the total areas sampled for TPC failed to comply with the legal requirements for food surfaces specified in the South African Health Act (< 100 cfu.cm-2). Listeria was detected in 23 % of the samples taken and E.coli was found in 1.3 % of the samples, while S. aureus was not detected in any of the samples. Fifty percent of the plants applied conventional cleaning methods for cleaning and sanitation and the remaining 50 % used the low-pressure foam (LPF) method. The bacterial results of the two cleaning methods were statistically compared and a statistically significant difference (P ≤ 0.05) was found between the TPC means of the cleaning methods after cleaning. No statistically significant difference (P > 0.05) was found in terms of the Listeria species counts after both cleaning processes. The LPF method proved to be the superior cleaning option for reducing TPC counts. Secondly surface samples were collected from washed and sanitised dominant hands of food handlers and analysed for the presence of total plate counts, S. aureus and E. coli. The study aimed to evaluate the efficacy of hand washing practices and sanitation before commencing work. A total of 230 samples were collected, involving 100 % of the food handlers in selected convenience food outlets. The highest bacterial count taken from handswas 7.4 x 10-3 cfu.cm-2 and the lowest showed no detectable growth. Forty percent of the TPC analysed complied with the legal limit of < 100 cfu.cm-2 and only 18 % of the food handlers had no detectable bacteria present on their hands. One hand sample tested positive for E. coli, which is generally viewed as an indication of faecal contamination. S. aureus could not be detected on the hands of any of the food handlers. The results of this study indicated that hand hygiene is unsatisfactory and underlined the importance of further training to improve food handlers‘ knowledge of good hand washing practices. The study also aimed to present data on the food hygiene knowledge and practices of food handlers based on a representative sample from convenience food outlets in the Gauteng area. The management, as well as food handlers, were interviewed without prior announcement and managers were interviewed prior to starting their shifts, followed by food handlers, after they had passed through the change room and hand wash facilities. Although the majority of food handlers adhered to basic hygiene principles, the results highlighted a need for proper and continuous training in hygiene practices, not only for food handlers, but also for management. Furthermore, all food handlers should adhere to a formal cleaning schedule and specific courses should be planned for food handlers. Most training is done away from the workplace and the workers might find it difficult to translate theory into practice. Although food safety training programmes are essential, behavioural changes will not occur merely as a result of having received training but rather continuous development of food handlers. In conclusion, the popularity of convenience food is bound to increase with the growing appeal for modern foods. Consumers in South Africa nowadays demand good quality and safe products at a reasonable cost. Due to continuous time constraints, convenience food is the food of the future for the working mother. It is clear that managing foodborne disease is a challenge and an economic problem subject to various constraints. Food safety has too often become a hit-or-miss gamble, with parents obliged to roll the dice when it comes to the safety of their children‘s food and consumers in general. The food industry therefore needs to improve food safety processes to prevent the contamination of foods and use methods to ensure safe food for consumers. Better training, more testing and better methods of tracking food must be utilised to verify that the processes are working. This study endeavoured to add to the understanding and improvement of hygiene processes as well as food handlers‘ practices in the convenience food industry in the Gauteng Province.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Na drenagem ácida de mina a contaminação pelo manganês é notável e se caracteriza como um dos principais problemas ambientais vivenciados pela indústria mineradora. Este elemento tem sido frequentemente encontrado em concentrações muito acima do limite permitido para o lançamento que, de acordo Resolução CONAMA No. 430, é de 1,0 mg/L. Neste contexto, a precipitação oxidativa com KMnO4, quando empregada para recuperação e remoção do manganês, se destaca como um processo promissor. Neste trabalho, a primeira etapa constou de um planejamento estatístico onde foi possível a avaliação da influência de parâmetros de processo e a modelagem empírica da precipitação oxidativa do Mn II em amostras preparadas em laboratório. Foram avaliados quatro parâmetros: a dose de KMnO4, o pH, o tempo de reação e a concentração da solução de KMnO4. Apenas a dose de KMnO4, o pH e a interação entre estes dois fatores apresentaram influência significativa sobre o processo de precipitação oxidativa do manganês. Na etapa de otimização, a análise do aspecto das superfícies de resposta, descritas por modelos matemáticos empíricos, permitiu avaliar as combinações entre o pH e a dose de KMnO4 que contribuem para uma maior eficiência do processo. Os melhores resultados foram obtidos para doses de KMnO4 de 1,63 mg KMnO4/mg Mn II em pH 3,0 e 1,54 mg KMnO4/mg Mn II em pH 5,0. As remoções de manganês observadas nestas condições foram 99,84% e 99,90% respectivamente, para uma concentração inicial de 100 mg/L. Posteriormente, o estudo cinético do processo utilizando soluções de Mn II preparadas em laboratório, mostrou que a precipitação do manganês com KMnO4 apresenta a vantagem de ser rápida. A concentração de Mn II decresceu exponencialmente atingindo limites inferiores a 1,0 mg/L em menos de 10 minutos de reação. A cinética da reação foi favorecida com a elevação do pH. Os precipitados formados apresentaram baixa cristalinidade com pequenas diferenças morfológicas em função do pH do meio, sendo a fase mineralógica encontrada a birnessita (MnO2), de acordo com espectroscopia RAMAN. Estas observações experimentais estão de acordo com os resultados da modelagem realizada com o programa PHREEQC, na qual a presença do óxido de manganês MnO2 foi confirmada nas fases birnessita, pirolusita e nsutita. Na etapa final, amostras de drenagem ácida oriundas de uma antiga mina de urânio desativada foram caracterizadas quimicamente e submetidas ao tratamento com KMnO4 em escala laboratorial. A caracterização das amostras mostrou que os parâmetros que estão fora da especificação segundo a legislação são o manganês, o fluoreto e também o pH. Além disso, as concentrações de cálcio, alumínio e sulfato são relativamente elevadas. O ensaios de precipitação oxidativa foram conduzidos em valores de pH 3,0, 5,0 e 7,0. Em pH 7,0 o processo mostrou-se mais eficiente, não apenas em relação a remoção de Mn II, que alcançou níveis de aproximadamente 99 %, mas também em termos da velocidade de reação, sendo o equilíbrio atingido em 10 min de reação. Verificou-se uma remoção mais significativa dos outros componentes como ferro, alumínio e urânio na etapa de ajuste do pH para 7,0 com NaOH. Os precipitados formados na etapa de oxidação não apresentaram cristalinidade, contudo foram identificadas as fases birnessita (MnO2), hausmanita (Mn3O4) e manganita (MnOOH), de acordo com espectroscopia RAMAN. Além do manganês, foram detectados nos precipitados: alumínio, cálcio, zinco, urânio, terras raras, oxigênio e flúor. A simulação com o PHREEQC permitiu a identificação das fases termodinamicamente possíveis em cada etapa do processo. Na etapa de ajuste de pH foram formadas, principalmente, fases contendo ferro, urânio, alumínio e o manganês. A etapa de adição do agente oxidante foi caracterizada por remoções de manganês nas fases birnessita (MnO2), bixbyita (Mn2O3), hausmanita (Mn3O4), manganita (MnOOH), nsutita (MnO2), pirolusita (MnO2) e cálcio na forma de fluorita (CaF2) / The manganese contamination present in acid mine drainage is outstanding as one of the main environmental issues experienced by the mining sector. This element has been frequently found in concentrations much higher than the allowed limit for discharge which is 1.0 mg/L according to Brazilian legislation, CONAMA No. 430. In this context, the oxidative precipitation by KMnO4, when employed to recover and remove manganese is a promising process. In this work, throughout a statistical design it was possible to assess the influence of process parameters as well as the empirical modeling of oxidative precipitation of Mn II in laboratory prepared samples. The experiments consisted of evaluating four parameters: the KMnO4 dose, pH, reaction time and concentration of KMnO4 solution. Only the dose of KMnO4, the pH and the interaction between these two factors have shown significant influence. In the optimization stage, by observing the aspect of the response surfaces, described by empirical mathematical models, it was possible to find out the combinations between pH and KMnO4 dose that could increase the process efficiency. The best results were obtained throughout trials conduct at pH 3.0 with KMnO4 ratio of 1.63 mg KMnO4/mg Mn II and at pH 5.0 with ratio of 1.54 mg KMnO4/mg Mn II. The manganese removals under these conditions were 99.84% and 99.90%, respectively. Subsequently, the kinetics study was carried out by using solutions of Mn II prepared in the laboratory. The results have shown that the precipitation of manganese by KMnO4 has the advantage of being fast. The concentration of Mn II decreases exponentially reaching the lower limit of 1.0 mg/L around 10 minutes of reaction. Additionally, the kinetics of the reaction is favored with increasing pH. The produced precipitates have low crystallinity and show slight morphologic differences according to the pH assessed. The main mineral phase identified by RAMAN spectroscopy was birnessite (MnO2). These experimental observations match with the modeling results performed withPHREEQC, in which the presence of manganese oxide MnO2 was identified as birnessite, pyrolusite and nsutita. In the final step, samples of acid mine drainage originated from one former and inactive uranium mine were chemically characterized and underwent with KMnO4 in bench scale. The samples characterization showed that manganese, fluoride and the pH are beyond limits set by legislation. Furthermore, the calcium, aluminum and sulphate are present in relatively high concentrations. The oxidative precipitation trials were carried out at pH 3.0, 5.0 and 7.0. At pH 7.0 the process was more efficient for the removal of Mn II, which accomplished levels of approximately 99%, and also in terms of reaction rate, the equilibrium was achieved within 10 min of reaction. Under the same condition i.e., at pH 7.0, there was an increase in the removal of other components such as iron, aluminum and uranium. The precipitates formed were not crystalline; nevertheless it was possible to identified the phases birnessite (MnO2), and possibly hausmanita (Mn3O4) and manganite (MnOOH) by RAMAN spectroscopy. Besides manganese, the species aluminum, calcium, zinc, uranium, rare earths, oxygen and fluorine were also detected in the precipitated. The simulation with PHREEQC enabled the identification of thermodynamically possible phases at each stage of the process. In the step of pH adjustment, essentially, phases containing iron, uranium, manganese and aluminum are formed. The adding of KMnO4 is characterized by manganese and calcium removal as birnessite (MnO2), bixbyite (Mn2O3), hausmaninte (Mn3O4), manganite (MnOOH), nsutite (MnO2), pyrolusite (MnO2) and fluorite (CaF2).

Nenhuma / A existência de uma área contaminada pode gerar problemas tais como danos à saúde, comprometimento da qualidade dos recursos hídricos, restrições ao uso do solo e danos ao patrimônio público e privado como, por exemplo, a desvalorização das propriedades, além de danos ao meio ambiente. A constatação da existência de passivo ambiental em local objeto de novos licenciamentos ou renovações pode dificultar ou até impedir a obtenção de novas licenças por parte do empreendedor. Os Valores de Referência de Qualidade (VRQ) são definidos como sendo a concentração de uma determinada substância no solo ou na água subterrânea e determinam um solo como limpo ou a qualidade natural da água subterrânea. Em âmbito mundial, os VRQ são bastante heterogêneos. No Brasil poucos estudos foram concluídos para se estabelecer esses valores, em especial, para os radionuclídeos das séries naturais do urânio e tório. Na ausência de VRQ para radionuclídeos em solos, são utilizados valores genéricos internacionais. Entretanto, deve-se ressaltar que esta prática pode levar a avaliações inadequadas, já que existem diferenças marcantes nas características físicas de cada região, em especial, das condições geológicas, hídricas e pedológicas. Essas diferenças justificam o desenvolvimento de uma tabela própria com VRQ para radionuclídeos naturais em solos específicos para cada região. Dando continuidade ao projeto Determinações de Valores de Referência para Elementos-Traço em Solos do Estado de Minas Gerais foi detectada a necessidade da determinação da concentração de atividade de radionuclídeos naturais nos solos. Dentro deste contexto, o principal objetivo deste trabalho é determinar os valores de referência de qualidade de solo para U e Th no Estado de Minas Gerais. Foram obtidos os seguintes valores de referência para qualidade de solo no Estado de Minas Gerais: 101,6 Bq.kg-1 (4,2 &#956;g/g) para o U e 75,7 Bq.kg-1 (18,6 &#956;g/g) para o Th. A análise estatística demostrou que o U e o Th apresentam correlação positiva com a classe dos Latossolos, bem com o conteúdo de argila e a matéria orgânica presente nos solos. Os resultados encontrados na Análise de Componentes Principais indicaram a existência de uma correlação positiva da concentração de U com os elementos As e Sb e o Th, principalmente, com o Ba e o Cd. / The existence of a contaminated area may pose several problems, such as health hazards, lessening of water resources quality, restrictions to the use of soils and damages to public and private property like, for instance, depreciation of their patrimonial and commercial values, besides, of course, the consequent impacts to the environment. Upon the configuration of an environmental degradation in a given site expected to be licensed or to have some kind of license renewed, this feature may retard or even impede the concession of new licenses to the entrepreneur. The Quality Reference Values (QRV) are defined as the concentration of a given substance in the soil or in groundwater, which determine a soil as being clean or determine the natural quality of the groundwater. Worldwide, QRV are very heterogeneous. Few studies have been carried out in Brazil with the purpose of establishing such reference values, in particular regarding the natural radionuclides of the uranium and thorium series. Considering the non-existence of such reference values for Brazilian soils, professionals tend to apply generic international values from literature. This practice, however, may result in inadequate evaluations, given that there exist outstanding physical differences among different regions of the country, in particular those concerning geological, hydrological and pedological aspects. Therefore, this heterogeneity may be the justification for the construction (elaboration) of a specific set of Quality Reference Values for natural radionuclides in soils for each specific region of interest. As a consequence of the development of the Project Determination of Reference Values for Trace Elements in Soils of the State of Minas Gerais, it was identified the need and importance of determining the activity concentrations of natural radionuclides in the mentioned soils. In this context, the main objective of the present work was to determine the Quality Reference Values of soils for U and Th in Minas Gerais. The following values have been defined: 101,6 Bqkg-1 (4,2 &#956;g/g) for U and 75,7 Bq.kg-1 (18,6 &#956;g/g) for Th. The statistical analysis of the all data showed that U and Th have a positive correlation with the soil class of Oxisols, as well as with the clay and organic matter content. The results on Principal Component Analysis indicated the existence of a positive correlation of U concentration with the elements As and Sb, and Th, mainly, with Ba and Cd.