The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on December 29, 2009). Thesis advisor: Dr. Andrew D. Clarke. Includes bibliographical references.

M. Tech. Food Technology. / Problems to be solved in this project was to validate isolation and detection methods for C. koseri; to assess the environmental prevalence of C. koseri by testing a range of raw South African food products and to determine the specific risk of neonatal infections by monitoring powdered infant formula on the South African market for the presence of this organism.

M. Tech. Chemistry. / Aims to evaluate, compare and modify existing methods and investigate new methods for the qualitative and quantitative determination of melamine. Specific aims were to: evaluate and modify an existing GC-MS15 and HPLC-DAD method16, published by US FDA, for the determination of melamine in pet food and baby milk powder formulae ; develop a novel HPLC fluorescence detection (FLD) method for the determination of melamine in pet food and baby milk powder formulae ; compare these methods to a commercial ELISA detection method for the determination of melamine in pet food samples previously implicated in the poisoning of dogs ; apply NIR spectroscopy with subsequent multivariate analysis to rapidly determine melamine in pet food; and compare the different methods statistically with respect to their analytical performances.

Sparti pramonės ir urbanizacijos plėtra iškėlė naujų saugios mitybos problemų nes atsirado pavojus užteršti maisto produktus pramonės ir buities atliekomis bei naujomis cheminėmis medžiagomis. Ypač pavojingi yra sunkieji metalai, chlororganiniai pesticidai ir PCB. Šie teršalai, nors jau nebenaudojami apie 30 metų ir jų visiškai neturi būti, jie vis dar randami, nors ir nedideliais kiekiais mūsų maiste. Jie pasižymi ilgaamžiškumu ir savybe kauptis gyvuosiuose organizmuose,todėl yra pagrindinių mūsų laikų ligų, tokių kaip vėžys, kraujotakos organų ligos, vidaus sekrecijos liaukų ir kitų organų veiklos sutrikimų iniciatoriai. Tikslas - išanalizuoti maisto produktuose aptiktus sunkiuosius metalus ir pesticidus,PCB bei palyginti šiuos duomenis su Lietuvos Respublikos ir Europos Sąjungos teisės aktais. Uždaviniai:  Literatūros apžvalgoje aptarti sunkiųjų metalų, pesticidų ir PCB ypatumus, jų patekimą į maisto produktus.  Apžvelgti maisto produktų užterštumą sunkiaisiais metalais ir pesticidais Lietuvoje ir kitose šalyse.  Nustatyti veiksnius, kurie lemia skirtingos rūšies maisto produktuosų užterštumą.  Apibendrinti literatūrą, nagrinėjančią sunkiųjų metalų ir pesticidų savybes, išanalizuoti sunkiųjų metalų ir pesticidų įtaką žmogaus sveikatai.  Išanalizuoti gautus sunkiųjų metalų tyrimų rezultatus ir juos palyginti su HN- 54: 2003 reglamentuotomis sunkiųjų metalų normomis, bei EB Nr. 1881/2006 reglamentuotomis normomis. Darbo aktualumas. Mityba, suvartojamo maisto... [toliau žr. visą tekstą] / The rapid expansion of industry and urbanization caused the new problems of safe nutrition, because the danger was caused to contaminate the food products with industrial and household waste and new chemical substances. The heavy metals, chlororganic pesticides and PCB are especially dangerous. Although these pollutants have not been used for about 30 years, they are still found in our food. They are characterized by long life and ability to accumulate in the live organisms; therefore they are the initiators of the principal modern diseases, such as cancer, vascular diseases, disorders of inner secretion glands and other organs. The purpose is to analyze the heavy metals, pesticides and PCB encountered in food products, and to compare this data with the legal acts of the Republic of Lithuania and the European Union. Tasks:  To discuss the peculiarities of heavy metals, pesticides and PCB in the survey of literature and their way to the food products.  To determine the factors, which cause the different contamination in food products.  To generalize the literature that analyzes the features of heavy metals and pesticides, and to analyze the influence of heavy metals and pesticides on human health.  To analyze the results received from the tests of heavy metals, and to compare them with the norms stated for the heavy metals in HN – 54: 2003, and with the EU No. 1881/2006 norms. Topicality of the work. The nutrition, assortment of used food and its quality have a big... [to full text]

Quality control procedures during food processing may involve either lengthy enrichment steps, precluding enumeration of bacteria in contaminated food, or direct inoculation of food samples onto appropriate selective media for subsequent enumeration. However, sublethally injured bacteria often fail to grow on selective media, enabling them to evade detection and intervention measures and ultimately threaten the health of consumers. This study compares traditional selective and nonselective agar-based overlays versus two commercial systems (Petrifilm and Easygel) for recovery of injured Escherichia coli B-41560, originally an isolate from ground beef. Bacteria were propagated in tryptic soy broth (TSB), ground beef, or infant milk formula (IMF) to a density of 106-108 CFU/mL, and stressed for six minutes either in lactic acid (pH of 4.5) or heat-shocked for 3 min. at 60°C. Samples were pour- plated in basal layers of either tryptic soy agar (TSA), Sorbitol MacConkey (SMAC), or Violet Red Bile (VRB) agar and resuscitated for 4h prior to addition of agar overlays. Other stressed bacteria were plated directly onto the commercial media Petrifilm and Easygel. Our results indicate that the use of selective and nonselective agar overlays for sensitive recovery and accurate enumeration of E. coli B-41560 is dependent on the stress treatment and food system. These data underscore the need to implement food safety measures that address sublethally- injured bacteria such as E. coli O157:H7, without the use of enrichment steps, in order to avoid underestimation of true densities for target pathogens. / Department of Biology

The development of a scum in a commercial sports drink is of concern because the product would be of poor quality, which may result in financial losses due to consumer rejection of the product and hence a decrease in the firm’s market share. The scum could be harmful to health and as such the firm could be litigated. Several factors, including microbial proliferation, may be the cause of the development of a scum in sports drink, but the actual cause seems not to have been established. The aim of this study was to characterise the scum in sports drink and determine the effects of preservation factors (pasteurisation, chemical preservatives and refrigeration) on its development. Samples of the sports drink were taken at different stages of processing to determine the effect of preservatives, pasteurisation and storage temperature on scum development. Some samples were kept at room temperature (approx. 25°C) and others were kept in the refrigerator (approx. 4ºC) during the study. A total of 150 samples were analysed over a period of four months. The structural characteristics of the scum that developed in the sports drink were determined by scanning electron microscopy (SEM) and elemental analysis. The sports drink samples were analysed for their microbial load and microbial types. Consumer acceptability of pasteurised and non-pasteurised drink was compared by conducting sensory evaluation using a consumer panel of 60 panellists. Customer complaints recorded by the sports drink manufacture that were due to scum development in the drink were also reviewed to establish the impact of scum development on consumer acceptability of the drink. The results of the study indicated that scum development was due to microbial contamination of the drink. The causative organism of the scum was identified as Acinetobacter baumanii. Acinetobacter baumanii is a gram negative non-spore forming coccobacilli and does not ferment sucrose. Acinetobacter baumanii forms the scum in sports drink as a means of protection from environmental stresses. The scum was found to be a compound of C, Si and O. The non-pasteurised samples were slightly more acceptable to consumers compared to the pasteurised samples. The consumer acceptability of pasteurised drink samples was negatively affected by the loss of aroma and flavour during pasteurisation. The preservation factors (chemical preservatives, pasteurisation and refrigeration) had no effect on scum development. To prevent post pasteurisation contamination, it is recommended that the pasteurisation process be done at the filling stage instead of at the holding stage. The frequency of changing rubbers and gaskets on the filling line should be at least every two months. The drink is pasteurised at 90ºC for 20 seconds, this needs to be reduced to a level where it will not have an influence on the loss of taste and aroma of the pasteurised drink, but without reducing the effectiveness of pasteurisation. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

Thesis (PhD) -- University of Western Sydney, 2003. / "A thesis submitted for degree of Doctor of Philosophy, Centre for Advanced Food Research, School of Science, Food & Horticulture, University of Western Sydney, Hawkesbury campus, Richmond, Australia, January 2003" Bibliography: leaves 199-227.

Thesis (M.S.P.H.)--University of Michigan, 1939.