Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 116-121). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 116-121). Also available on the Internet.

No description available.

Meat and poultry slaughtering and processing practices have been associated with the microbial contamination with Listeria spp. Ready-to-eat poultry products have been considered as a primary agent associated with Listeria monocytogenes illness outbreaks. Developing environmental monitoring programs (EMPs) that are based on product and/or process risk level analysis is a useful approach to reduce contamination in poultry processing plants and enhance food safety. Sampling criteria that is based on product risk levels and process control in ready-to-eat poultry processing facilities was developed to allow users to design and conduct appropriate sampling plans to target Listeria spp. After developing the criteria, an internet-based environmental monitoring program ("EZSafety") was developed to allow poultry producers to enhance their sample collection and analysis of test results over time and conduct appropriate sampling plans for Listeria spp. and other microbiological indicators. The frontend of the program website was built using React Native (an open-source JavaScript library for building user interfaces). The backend of the program website was built using Node.js which executes JavaScript code outside a web browser. MongoDB was used as a document-oriented database for the website. The program was evaluated by 20 food safety professionals to assess its ability to develop appropriate sampling plans to target Listeria spp. The majority of these participants believed that EZSafety has several tools that are effective for targeting Listeria spp. and other indicators and enhancing environmental monitoring. Additionally, most participants agreed that EZSafety is organized and user-friendly. EMPs can play a significant role in improving the detection rate and the prevention of Listeria spp. and other indicators in poultry processing plants. / Master of Science in Life Sciences / Meat and poultry slaughtering and processing practices have been associated with the microbial contamination with a bacterium known as Listeria. Cooked poultry products during the manufacturing process have been considered as a primary agent associated with Listeria monocytogenes (disease causing type of bacteria) sickness outbreaks. Developing environmental monitoring plans to detect and prevent this bacterium in poultry processing establishments is a useful approach to reduce contamination and enhance food safety. Several guidelines and baselines were developed to allow users to design and conduct appropriate environmental monitoring plans to target this bacterium. After developing these guidelines and baselines, an internet-based environmental monitoring program ("EZSafety") was developed to allow poultry processors to enhance their sample collection and analysis of test results over time. The program was developed using several kinds of computer platforms (JavaScript, React Native, and MongoDB) . These open-source platforms were used to design, develop, and store the program over the internet. In order to validate its usefulness, the program was evaluated by 20 users who are majored in food safety and familiar with poultry processing plants hygiene to assess its ability to suggest appropriate monitoring plans. Most of the participants believed that EZSafety has several tools that are effective for targeting Listeria and other kinds of bacteria and enhancing environmental monitoring plans. Additionally, most participants agreed that EZSafety is organized and user-friendly. Such automated monitoring programs can play a significant role in enhancing the detection rate and the prevention of Listeria and other organisms in poultry processing facilities.

Utilizing data collected by the University of Kentucky Lung Cancer Research Initiative (LCRI), this study investigated potential mining-related sources for the elevated levels of cadmium in Harlan and Letcher counties. Statistical analyses for this study were conducted utilizing SAS. A number of linear regression models and logarithmic models were used to evaluate the significance of the data. The linear regression models consisted of both simple and multivariate types, with the simple models seeking to establish significance between the potential sources and urine cadmium levels and the multivariate models seeking both to identify any statistically significant linear relationships between source types as well as establish a relationship between the potential source and the urine cadmium levels. The analysis began by investigating which ingestion method caused the increased levels of cadmium exposure. The analysis included ingestion through water sources and inhalation of dust. Of these two, dust showed the higher level of correlation. The second step was to analyze a number of sources of dust, particularly those related to mining practices in the area. These included the proximity to the Extended Haul Road System, secondary haul roads, rail roads, and processing plants. Of the variables in the analysis, Extended Haul Roads, secondary haul roads, and rail roads showed no correlation, and only the proximity to processing plants showed statistical significance.

need to dry-mill the wheat into flour, and as a result, the total cost of conversion from wheat to bread is reduced. The resulting product has been perceived as being more filling than normal bread and it is also more nutritious and more affordable. The wet-mill concept was developed in a laboratory environment and no process methodology or equipment has existed to enable the technology to be used in a real bakery environment. The focus of this research was to design the particular equipment required for a medium plant-bakery production facility based on the wet-mill technology. Due to severe overcapacity in the bread-making industry, the research focuses on how best to integrate this equipment into an existing production facility. Three broad areas are investigated: • Product Development • Process Design • Machine Design The aim of the Product Development phase was to create a recipe that would withstand the rigours of the plant bakery environment, while at the same time satisfying consumer demand for taste and texture. The Process Design phase ensured that any new equipment had the capacity to match the throughput rate of the rest of the plant bakery, so that wet-mill dough could seamlessly continue downstream. Process control variables were examined to ensure that a consistent quality product was delivered. Inbound material handling was also investigated and designed to ensure safe and uncontaminated delivery of perishable raw material. Since the end product is edible, hygiene design requirements were also considered by completing a HACCP study to ensure a consumer-safe product. The Machine Design phase involves the development and design of a completely new food machine: a vertical wet-mill cutter. Many ideas are evaluated and a prototype machine, based on the optimal design, was built to test the concept. This prototype was then used to define process and design constraints for a scaled, large plantbakery machine. The final detailed design of a plant bakery wet-mill cutter was then completed. It includes drive, belt, bearing and pneumatic cylinder selection, and shaft and blade design. Safety considerations were an important part of the design process and production facility. Conformity to OHS Act regulations required investigation into the safe operation of the designed equipment with particular reference to driven and rotating machinery sub-regulations of the Act. A hazard analYSis and operability study was also undertaken. Lastly, the research calculates a financial valuation of the project to ascertain whether a plant baker should be interested in implementing wet-mill technology. The research concludes with a discussion of the various successes of the three research areas, and states any further investigation that may be required before full implementation. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

Thesis (Ph.D.)--Victoria University (Melbourne, Vic.), 2008.

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Made available in DSpace on 2014-08-20T13:42:06Z (GMT). No. of bitstreams: 1 Denise da Fontoura Prates.pdf: 535436 bytes, checksum: c3acb08e8f12a05440096b13c688b6f2 (MD5) Previous issue date: 2010-12-17 / Listeria monocytogenes is a Gram-positive of ubiquitous natural, psychrotropic pathogen which colonizes the surfaces of equipment and utensils in food processing industries. Milk and dairy products, especially cheeses with medium and high humidity have been implicated in listeriosis cases and outbreaks. Microbial contamination could be originated in raw material or be incorporated during the development stages of the product, coupled with inadequate hygiene practices. The general aim of this study was to evaluate the occurrence of Listeria spp. along the processing line of cheese with middle and high humidity, in three dairy subjected to different levels of sanitary survey located in Southern Brazil. From 208 samples tested Listeria spp. were isolated 7.69%, being isolated 43.75%, 25%, 31.25%, respectively, in dairy products A, B and C. From these isolates, 25% were found in raw milk, 18.75% in contact surfaces with the product, 50% in areas without contact with the product and 6.25% in the final product. L. innocua and L. monocytogenes were the only species identified between the isolates being L. innocua the prevalent species (68.7%). Among the serotypes of L. innocua, the serotype 6a was prevalent (72.7%) and between L. monocytogenes serotype 4b was prevalent (55.6%). All Listeria strains isolated from raw material and final product showed multiresistance to five antibiotics (penicillin, amoxicillin, chloramphenicol, cefaclor and clindamycin) of the fifteen antibiotics tested. Among the samples of raw material assessed microbiologically, the raw milk showed the highest levels of contamination and the highest levels found between them were > 1.1x106 MPN/mL for fecal Overall, 1.1x105 MPN/mL for fecal coliform, 4x105 CFU/ml for coagulase-positive staphylococci and Salmonella spp. in one of the samples. Among six samples of the final product, only one showed himself at odds with the existing regulatory standard, exceeding the allowed limit for ECP. Listeria spp. and L. monocytogenes were present along the lines of the three dairy processing plants, regardless of the size of the industry, highlighting the risk of contamination during food manufacturing. Therefore, it becomes necessary to introduce effective measures to reduce such contamination or improvements in the practices already adopted by the industry, because of the risks to public health. / Listeria monocytogenes é uma bactéria Gram-positiva de natureza ubíqua, psicrotrófica, que coloniza superfícies de equipamentos e utensílios dentro de indústrias processadoras de alimentos. Leites e derivados lácteos, em especial queijos com média e alta umidade, têm sido incriminados em casos e surtos de listeriose, por serem alimentos que favorecem o desenvolvimento microbiano, além de serem prontos para o consumo. A contaminação microbiana pode ter origem na matéria-prima, ou ser incorporada durante as etapas de elaboração do produto, associada a práticas inadequadas de higiene. O objetivo geral neste trabalho foi avaliar a ocorrência de Listeria spp., em especial de L. monocytogenes, ao longo da linha de processamento de queijos de média e alta umidade, em três laticínios, localizados na região sul do Rio Grande do Sul, submetidos a diferentes níveis de inspeção sanitária. Das 208 amostras avaliadas 7,69% apresentaram Listeria spp., sendo isoladas, 43,75%, 25%, 31,25%, respectivamente, nos laticínios A, B e C. Destes isolados, 25% foram encontrados no leite cru, 18,75% em superfícies de contato com o produto, 50% em superfícies sem contato com o produto e 6,25% no produto final. L. innocua e L. monocytogenes foram as únicas espécies identificadas entre os isolados, sendo L. innocua a espécie prevalente (68,7%). Entre os sorotipos de L. innocua, o prevalente foi 6a (72,7%) e entre L. monocytogenes o sorotipo prevalente foi 4b (55,6%). Todas as cepas de Listeria isoladas da matéria-prima e do produto final apresentaram multirresistência a cinco (penicilina, amoxilina, cloranfenicol, cefaclor e clindamicina) dos 15 antibióticos testados. Dentre as amostras de matéria-prima avaliadas microbiologicamente, as de leite cru, foram as que apresentaram os maiores níveis de contaminação, sendo que, os níveis mais elevados encontrados entre as amostras de leite cru foram: >1,1x106 NMP.mL-1 para coliformes totais, 1,1x105 NMP.mL-1 para coliformes termotolerantes, 4x105 UFC.mL-1 para estafilococos coagulase positiva (ECP) e a presença de Salmonella spp. em uma das amostras avaliadas. Entre as seis amostras de produto final, apenas uma apresentou-se em desacordo com o padrão regulamentar vigente, excedendo o limite permitido para ECP. Listeria spp. e L. monocytogenes foram isoladas ao longo das linhas de processamentos nos três laticínios, independente do porte da indústria, evidenciando risco de contaminação durante a fabricação dos dois tipos de queijo, os quais são produtos prontos para o consumo. Dessa forma, torna-se necessária a implantação de medidas eficazes para redução dessas contaminações, ou melhorias nas práticas já adotadas pelas indústrias, em virtude dos riscos à saúde pública.