Tegel Foods Limited produces an extensive range of poultry products which may contain various potential allergens. These include wheat, soy, milk, and egg, sometimes in combination. This research has two purposes. One was to examine three cleaning stages of processing equipments – Rinse only, Foam and rinse and Sanitise and rinse to validate the efficacy of cleaning required between production runs where the first but not the second product contains the allergen. The allergen chosen to model the cleaning efficacy was gliadin, a protein in wheat. The second aim was to quantify allergenic risk to consumers from inadequately cleaned conveyer surfaces. The commercial motives driving this research were as follows. Cleaning represents a loss in productivity and an increase in consumables costs, and if it can be minimised, this would be advantageous. The requirement to declare the possibility of cross-contamination on retail packaging can potentially adversely affect consumer response, and if these declarations can be avoided then this too would be a commercial advantage. Three approaches were adopted or developed, an ATP bioluminescence test, an ELISA test kit for gliadin, and a Coomassie Blue test to quantify protein given that most allergens are proteins. Fifteen trials were done in the High Care Zone and the Old Further Processing line of the Tegel Henderson Plant production area over a period of nine months. In a typical trial, gliadin values normalised to Uncleaned values fell from 1000 (Uncleaned) arbitrary units, to 60 (Rinse only), to 0.3 (Foam and rinse), to zero (Sanitise and rinse). Parallel ATP tests similarly showed a progressive decrease in values. Compared with Uncleaned, the relative gliadin value was less than the relative ATP value after Foam and rinse in 14 of 14 trials. After Sanitise and rinse the same result was obtained. In the equivalent trials with ATP and Coomassie Blue, after cleaning of Foam and rinse and Sanitise and rinse, the relative ATP values exceeded the relative Coomassie Blue values in four of the five trials. Therefore the considerably cheaper and simpler ATP test is not only an indicator of hygiene but also a good guide to gliadin concentration (gliadin test), and to allergen contamination in general on the basis that allergens are mostly proteins (Coomassie Blue). Modelling of second-product contamination has been done, and was based on knowledge of the absolute gliadin concentration on a typical Uncleaned conveyer surface, as established in the first part of this project. The concept of the worst-case scenario examined the highest possible risk that a sensitive consumer would be exposed to an allergenic dose of gliadin. A pickup efficiency fraction of 0.3 was assumed as an upper limit of contamination from conveyer to the surface of a previously uncontaminated chicken piece. The model showed that the highest concentration of gliadin on the second product would be 6.3 ppm which is below the legislated limit of low-gluten. Information of direct commercial interest to Tegel has been extracted from all these results, and suggestions for future research have been made.

Along with an increasing understanding of the harmful effects on the environment of a wide range of pollutants has come the need for more sensitive, faster and less expensive detection methods of identification and quantitation. Many environmental pollutants occur in low levels and often in complex matrices thus analysis can be difficult, time consuming and costly. Because of the availability and easy cultivation of the microorganisms with potentially high specificity, there is considerable interest in the use of living microorganisms as the analytical component (the biocomponent) of sensors for pollutants. While a number of biosensors using bacteria have been developed, yeast has been comparatively rarely used as the biocomponent. Yeast are attractive because they are easy to culture and they are eukaryotes which means their biochemistry is in many respects closer to that of higher organisms. This thesis describes the development of whole cell bioassays that use yeast cells as a sensing element and redox mediators to probe the intracellular redox reactions to monitor the catabolic activity of the yeast resulting from the external substrate, steady-state voltammetry is utilised as the electrochemical detection technique. The isogenic differential enzyme analysis (IDEA) concept of Lincoln Ventures Limited, lead NERF funded research consortium uses bacteria that have been cultured using specific organic pollutants as the carbon source which are the biocomponent in sensors. The use of wild type yeast Arxula adeninivorans that has the ability to use a very wide variety of substrates as sources of carbon and nitrogen was used as an alternative to bacteria to validate the “IDEA” concept. Naphthalene and di-butyl phthalate were chosen as model target contaminant molecules. The performance, detection limits and the usefulness of yeast based biosensor applications for environmental analysis are discussed. This thesis also describes the development and optimisation of a simple, cost effective in vivo estrogens bioassay for the detection of estrogens using either genetically modified or a wild type yeast Saccharomyces cerevisiae. In this study, catabolic repression by glucose was exploited to achieve specificity to estrogens in complex environmental samples that eliminates the requirement for conventional sample preparation. This is the first time that the use of wild type yeast to quantify estrogens has been reported. The attractive features of the bioassay are its use of a non-GMO organism, its speed, its high specificity and sensitivity with a detection limit of 10-15 M. The similarity of binding affinities for major estrogens to those of human estrogens receptors makes this in vivo estrogen bioassay very useful for analytical/screening procedures. The electrochemical detection method also makes it easy to interface with a variety of electronic devices.

Tegel Foods Limited produces an extensive range of poultry products which may contain various potential allergens. These include wheat, soy, milk, and egg, sometimes in combination. This research has two purposes. One was to examine three cleaning stages of processing equipments – Rinse only, Foam and rinse and Sanitise and rinse to validate the efficacy of cleaning required between production runs where the first but not the second product contains the allergen. The allergen chosen to model the cleaning efficacy was gliadin, a protein in wheat. The second aim was to quantify allergenic risk to consumers from inadequately cleaned conveyer surfaces. The commercial motives driving this research were as follows. Cleaning represents a loss in productivity and an increase in consumables costs, and if it can be minimised, this would be advantageous. The requirement to declare the possibility of cross-contamination on retail packaging can potentially adversely affect consumer response, and if these declarations can be avoided then this too would be a commercial advantage. Three approaches were adopted or developed, an ATP bioluminescence test, an ELISA test kit for gliadin, and a Coomassie Blue test to quantify protein given that most allergens are proteins. Fifteen trials were done in the High Care Zone and the Old Further Processing line of the Tegel Henderson Plant production area over a period of nine months. In a typical trial, gliadin values normalised to Uncleaned values fell from 1000 (Uncleaned) arbitrary units, to 60 (Rinse only), to 0.3 (Foam and rinse), to zero (Sanitise and rinse). Parallel ATP tests similarly showed a progressive decrease in values. Compared with Uncleaned, the relative gliadin value was less than the relative ATP value after Foam and rinse in 14 of 14 trials. After Sanitise and rinse the same result was obtained. In the equivalent trials with ATP and Coomassie Blue, after cleaning of Foam and rinse and Sanitise and rinse, the relative ATP values exceeded the relative Coomassie Blue values in four of the five trials. Therefore the considerably cheaper and simpler ATP test is not only an indicator of hygiene but also a good guide to gliadin concentration (gliadin test), and to allergen contamination in general on the basis that allergens are mostly proteins (Coomassie Blue). Modelling of second-product contamination has been done, and was based on knowledge of the absolute gliadin concentration on a typical Uncleaned conveyer surface, as established in the first part of this project. The concept of the worst-case scenario examined the highest possible risk that a sensitive consumer would be exposed to an allergenic dose of gliadin. A pickup efficiency fraction of 0.3 was assumed as an upper limit of contamination from conveyer to the surface of a previously uncontaminated chicken piece. The model showed that the highest concentration of gliadin on the second product would be 6.3 ppm which is below the legislated limit of low-gluten. Information of direct commercial interest to Tegel has been extracted from all these results, and suggestions for future research have been made.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 149-178) Also available in print.

Thesis (M.Eng.). / Written for the Dept. of Chemical Engineering. Title from title page of PDF (viewed 2009/06/17). Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 149-178) Also available online.

Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on Apr. 16, 2010). Includes bibliographical references.

103 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-11T16:52:59Z No. of bitstreams: 1 dissertação versão impressão.pdf: 2800746 bytes, checksum: 4d63904f9a1733021edd1015bb31a294 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-05-10T17:10:19Z (GMT) No. of bitstreams: 1 dissertação versão impressão.pdf: 2800746 bytes, checksum: 4d63904f9a1733021edd1015bb31a294 (MD5) / Made available in DSpace on 2013-05-10T17:10:19Z (GMT). No. of bitstreams: 1 dissertação versão impressão.pdf: 2800746 bytes, checksum: 4d63904f9a1733021edd1015bb31a294 (MD5) Previous issue date: 2011 / FAPESB / A cultura do tomate tem ocupado lugar de destaque em todo mundo. O aumento na produtividade da hortaliça provocou um aumento na utilização de insumos agroquímicos, fazendo-se necessário o monitoramento de elementos essenciais e elementos potencialmente contaminantes. Neste trabalho foram determinadas as concentrações de elementos essenciais e elementos potencialmente contaminantes em tomates das espécies caqui, itália e cereja, em cultivos convencional e orgânico, em fase inicial e final de maturação. As amostras foram coletadas em vários estabelecimentos da cidade de Salvador, Bahia, Brasil visando avaliar as diferenças nas concentrações entre os estágios de maturação, tipo de cultivo e espécie, no fruto inteiro e em suas partes (casca, polpa e semente). Os elementos estudados foram Al, Ba, Cd, Cu, Co, Cr, Fe, Mn, Ni, Pb, Sb, Se, Sn, Sr, V e Zn. Após otimização do procedimento de preparo, as amostras foram submetidas à digestão em forno de micro-ondas com cavidade, usando a mistura de 3,5 mL de ácido nítrico concentrado destilado, 3,5 mL de água ultra pura e 1,0 mL de peróxido de hidrogênio. Para determinação dos elementos foram empregadas as técnicas espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) e espectrometria de massas com plasma indutivamente acoplado (ICP-MS). Através dos resultados obtidos, foi possível comparar a concentração dos elementos estudados nos estágios de maturação, cultivo e espécies dos tomates analisados. Quanto ao estágio de maturação, os tomates em estágio final de maturação apresentaram maiores valores de concentração para a maioria dos elementos medidos, nas três espécies estudadas. Na comparação quanto ao tipo de cultivo, as amostras provenientes do manejo orgânico apresentaram maiores valores de micronutrientes e menores de elementos com potencial contaminante quando em comparação com as amostras de tomates oriundas de cultivo convencional. Em relação às diferentes espécies estudadas, observou-se que as amostras de tomate contribuem significativamente para a ingestão diária recomendada de Cr, Cu e Mn, sendo a espécie caqui a que mais contribui para a ingestão de Cu, a itália de Cr e a cereja de Mn. As concentrações dos elementos potencialmente tóxicos, encontradas para as amostras das três espécies de tomate, estão abaixo dos teores regulamentados pela ANVISA. Palavras-Chave: toma / Salvador

Our research investigated the correlations of five key contaminants in drinking water in the State of Illinois with the incidence rates of three different categories of negative reproductive outcomes: birth defects, adverse pregnancy outcomes and preterm births. The five water contaminants included three agrichemical-based contaminants (atrazine, nitrate and nitrite) and two disinfectant byproducts (total trihalomethanes and haloacetic acids). We obtained nearly 38,000 measurements of the individual concentrations of these five contaminants from the Illinois Environmental Protection Agency (IEPA). These data, spanning over a five-year period (1998-2002), were collected from nearly 1,800 community water supplies (CWS) located in all 102 Illinois counties. The county-specific incidence rate data for the same time period for preterm births, seven groups of birth defects and seven groups of adverse pregnancy outcomes were collected from the Illinois Department of Public Health (IDPH). The traditional approach of establishing correlation of one explanatory variable at a time indicated that nitrate concentration in drinking water was statistically correlated to the incidence rate of only one category of negative reproductive outcome, i.e., birth defects. However, multiple regression analysis, which took into consideration all water contaminant data simultaneously, established statistical significance of the correlation between nitrate and all three categories of negative reproductive outcomes. Total trihalomethanes (TTHM) and haloacetic acids (HAA5) were also found to be the statistically significant explanatory variables for all three types of negative reproductive outcomes. Nitrite was found to be associated with adverse pregnancy outcomes and preterm births only; its correlation with birth defect rates could not be established at 80% confidence level. Atrazine was found to be among the significant explanatory variables for all three negative reproductive outcomes. However, its correlations with birth defect model developed using censored data and preterm birth model developed based on observed data were not statistically significant. Nearly 21.5%, 35.8% and 16.6% of the variabilities in incidence rates of different types of birth defects, adverse pregnancy outcomes and preterm births, respectively, were correlated to average concentrations of above mentioned five contaminants in community drinking water supplies. The monthly average concentrations of two of three agrichemical-based contaminants, i.e., atrazine and nitrate were significantly higher in SW(surface water)-based than GW(ground water)-based community water supplies. On the other hand, concentrations of both disinfectant byproducts and the other agrichemical-based contaminant, i.e., nitrite were significantly higher in GW-based water supplies. Further correlation analysis based on the actual observed concentration (excluding all 0 detections) was conducted utilizing SW-based atrazine and nitrate data and GW-based nitrite, TTHM and HAA5 data. All categories of negative reproductive outcomes were found significantly correlated with at least one type of water contaminants. The overall negative reproductive outcomes were correlated with nitrate, nitrite and atrazine. Birth defects specifically correlated with nitrate and TTHM, whereas adverse pregnancy outcomes were correlated with nitrate, nitrite and HAA5; preterm birth was correlated with the concentrations of nitrite, atrazine and TTHM. Further investigation indicated significant correlations among the explanatory variables (drinking water contaminants data), which is referred as multicollinearity. In such case, multiple linear regression based analysis may not provide reliable results. Partial least squares (PLS) approach of regression analysis was introduced into our study to overcome the multicollinearity problem. As much as 65.5% of the variability in the county-wide average concentrations of five contaminants in public drinking water supplies was explained by the 4 component PLS regression model, whereas only 7.7% of the incidence rates of different types of birth defects, adverse pregnancy outcomes and preterm births in various Illinois counties, were explained by PLS regression. Although, individual negative reproductive outcome model could be generated, the low R2 values indicated the poor reliability of these models. We attempted to corroborate our statistical analysis findings with the physiological effects of various water contaminants reported in the literature. It is well known that excessive exposure to any of the five key water contaminants may cause malfunction of organism or the immune system, reproduction, nervous and endocrine system and others, which may further result in potential risk of developing adverse effects. Nitrate and nitrite in drinking water associate to a certain extent with congenital malformations, such as central nervous system abnormalities, in human offsprings. Excessive exposure to atrazine is known to increase the risk of potential cardiovascular or reproductive system problems. A certain type of TTHM, i.e., BDCM are known to be associated with an increased risk of spontaneous miscarriage in pregnant women. It also may result in an increased risk of reproductive problem, such as fetal growth restriction.

To date, limited research has been conducted on the effects of cytotoxic drugs on aquatic species. Three of these species, a single celled plant, an invertebrate and a fish, were exposed to six cytotoxic drugs, both singly and as simple mixtures. A range of endpoints were assessed, including growth inhibition in algae, immobilisation in daphnia and the impact on organ size and the expression of the DNA damage repair genes RAD51 and p53 in zebrafish. No effects at environmentally relevant concentrations were observed in any of the three species.