Food Microbiology Commons^™

The Effects Of Salinity On Pythium Disease Of Rice And Soybean, Terea Jeanette Stetina

Graduate Theses and Dissertations

Increasing salinity is an important factor limiting agricultural productivity worldwide. In addition to direct effects on growth and yield, diseases also may be affected. This study characterized the effects of soil salinity on seedling disease of soybean and rice caused by Pythium spp. Controlled environment experiments on soybean used two cultivars which differed in chloride tolerance and soil treated with a CaCl₂ solution to create a range of electrical conductivity (EC) levels. For soybean, soil was either not infested or infested with Pythium sylvaticum or P. aphanidermatum (pathogenic to soybean), or P. oligandrum (not pathogenic to soybean). Twenty-one days …

Effect Of Antimicrobials And Sodium Replacement Agents On The Survival Of Pathogenic Bacteria In Low Sodium Low-Moisture Part-Skim (Lmps) Mozzarella Cheese, Tiffany M J Taylor

Master's Theses

Recent increases in chronic cardiovascular diseases, such as hypertension, have put pressure on the food industry to reduce sodium levels. Dairy products, though full of vital nutrients, are perceived as being high in sodium. However, the reduction of salt in dairy products could potentially alter the microbial stability, as well as cause unfavorable changes in flavor. In order to reduce the sodium level, while maintaining acceptable flavor and microbial stability, salt replacers and alternative antimicrobial agents may need to be introduced into the food matrix. To identify potential antimicrobials for use in reduced sodium dairy products, this study evaluated the …

Effect Of Functional Starch In Brown Rice And Grain Sorghum On Plasma Glucose And Insulin Responses In Humans, Nicole Marie Poquette

Graduate Theses and Dissertations

Diabetes and obesity are chronic illnesses increasing at dramatic rates in the U.S. and around the world. Research has looked to prevent or control diabetes and obesity through functional ingredients such as healthy-dietary carbohydrates to control blood glucose levels. Starch is a principle carbohydrate, which influences blood glucose levels, and measuring starch digestibility fractions can help predict the glucose response in the body. The objectives of this study were to investigate the functional starch content of parboiled brown rice flour and grain sorghum flour, and measure the effects on postprandial plasma glucose and insulin levels of 14 and 10 healthy …

Effect Of Electrostatic Spraying Of Food-Grade Organic And Inorganic Acids, And Grape Seed Extract On Salmonella Typhimurium And Escherichia Coli O157:H7 On Spinach And Iceberg Lettuce, Vijayalakshmi Ganesh

Graduate Theses and Dissertations

The safety of fresh produce is often challenged by the sporadic incidences of outbreaks owing to Salmonella Typhimurium (S.T.) and Escherichia coli O157:H7 (E.c.). Washing and current disinfection strategies do not completely decontaminate leafy greens such as spinach and iceberg lettuce. Therefore, more effective treatments are essential to ensure the microbial safety of the produce at the selling point. Here, a multiple hurdle approach was applied: (1) Natural antimicrobials - organic acids (malic, lactic and tartaric acids; MA, LA, TA, respectively) and plant extract (grape seed extract, GSE) and (2) Application method - Electrostatic spraying, was …

Electrostatic Spray Application Of Food-Grade Organic Acids And Plant Extracts To Decrease Escherichia Coli O157:H7 And Salmonella Typhimurium On Select Produce, Leighanna Maeree Massey

Graduate Theses and Dissertations

Both consumers and suppliers have been negatively affected by an increase in foodborne pathogens contaminating fruits. Consequently, there is a need for the development of more efficient antimicrobials and application techniques to decrease contamination. Natural preservatives such as organic acids and plant extracts have demonstrated promising results in decontaminating produce. In addition, the effectiveness of such preservatives may be enhanced by the use of an electrostatic sprayer. The objective of this research was to determine the combinations and concentrations of organic acids and plant extract that were able to reduce Salmonella Typhimurium (ST) and Escherichia coli O157:H7 (EC) inoculated fruits …

Physical And Biochemical Factors Affecting Breast Fillet Tenderness In Broilers Reared For Divergent Market Demands, Valerie Belle Brewer

Graduate Theses and Dissertations

Market trends have dictated that broilers be reared for divergent market demands for decades. Also, broiler genetic strains have been adapted to meet market demands which include: genetic selection for improved breast meat, the practice of growing birds to older ages and greater market weights to meet demands, and decreasing postmortem (PM) aging time to improve processing efficiency and fillet yield. These production practices can also affect product quality, specifically boneless breast fillet tenderness and water-holding capacity. To address these factors, a series of experiments were conducted to determine the effect of strain and slaughter age on meat quality parameters, …

Phenotypic, Physiological And Growth Interactions Among Salmonella Serovars, Juliany Rivera Calo

Graduate Theses and Dissertations

This thesis consists of four research parts: a literature review that covers Salmonella spp., one of the more prominent foodborne pathogens that represents a major risk to humans (chapter 1). Understanding the growth of Salmonella serovars and strains is an important basis for more in depth research. In this case we studied a) the aerobic and anaerobic growth responses of multiple strains from six different serovars, b) how the spent media from different serovars, more importantly S. Heidelberg, affect the growth of S. Typhimurium, and c) determined whether or not two different serovars undergo competitive interactions when they were …

Probiotics: Finding The Right Regulatory Balance, Diane E. Hoffmann, Claire M. Fraser-Liggett, Frank B. Palumbo, Jacques Ravel, Karen H. Rothenberg, Virginia Rowthorn

Faculty Scholarship

Some products marketed as drugs should be excused from Phase I trials, but safety and efficacy claims for dietary supplements should be more tightly regulated.

Food, Parasites, And Epidemiological Transitions: A Broad Perspective, Karl Reinhard, Luis Fernando Ferreira, Françoise Bouchet, L. Sianto, J. M.F. Dutra, A. Iniguez, Daniela Leles, M. Le Bailley, Martín Horacio Fugassa, Elisa Pucu, Adauto Araújo

Karl Reinhard Publications

Pathoecology provides unique frameworks for understanding disease transmission in ancient populations. Analyses of Old and New World archaeological samples contribute empirically to our understanding of parasite infections. Combining archaeological and anthropological data, we gain insights about health, disease, and the way ancient people lived and interacted with each other and with their environments. Here we present Old and New World parasite evidence, emphasizing how such information reflects the different ways ancient populations exploited diverse environments and became infected with zoonotic parasites. It is clear that the most common intestinal helminthes (worm endoparasites) were already infecting ancient inhabitants of the New …

Kinetic Studies For The Preparation Of Probiotic Cabbage Juice: Impact On Phytochemicals And Bioactivity, Amit Jaiswal, Nissreen Abu-Ghannam

Articles

A kinetic study for the production of probiotic cabbage juice was carried out under controlled pH and dissolved oxygen using several strains of Lactic acid bacteria (LAB). Furthermore, effect of probiotic fermentation on polyphenolic content and antioxidant capacity was investigated. Results showed significant growth in Lactobacillus brevis, Lactobacillus plantarum and Lactobacillus rhamnosus corresponding to 9.19, 9.47 and 10.6 log CFU/ml after 24 h of fermentation, which is satisfying criteria for a food product to be characterized as probiotic. Lactic acid (LA) was the major end product of the fermented cabbage juice attaining the concentrations of 6.97, 9.69 and 12.2 g/l …

Excretion Of Phenolic Compounds After Consumption Of Fresh Versus Aged Chokeberry Juice In Rats, Sarah Elizabeth Graves

Graduate Theses and Dissertations

Flavonoids, such as anthocyanins, may be responsible for the health benefits of chokeberries, as they are present in large quantities in chokeberries and are potent antioxidant and anti-inflammatory agents. Despite these health properties, previous investigations on the bioavailability of flavonoids illustrate that little of the ingested amount reaches the bloodstream. This study investigated two factors that may help to explain these inconsistencies. First, storage of berry fruits and berry fruit products leads to extensive polymerization of their anthocyanins with procyanidins. Additionally, after consumption flavonoids may undergo metabolism into phenolic acids and subsequent conjugation to an extent that may explain their …

Development Of Rapid Detection Methods And Novel Control Measures For Salmonella In Poultry, Si Hong Park

Graduate Theses and Dissertations

This dissertation consists of three research parts: 1) development of rapid detection methods for foodborne pathogens; 2) immune response of chicken cells against Salmonella and bacteriophage P22; 3) evaluation of novel control measures for poultry productions. In order to develop rapid and accurate detection methods for foodborne pathogens, two types of PCR assays were utilized. Three foodborne pathogens included Campylobacter, Escherichia coli and Salmonella in watershed were qualitatively and quantitatively detected by multiplex PCR and qPCR (chapter 2). Since Salmonella species are commonly present in poultry and poultry products as well as most popular foodborne pathogen in …

Characterization Of The Gut Microbiota And Colitogenic Bacterial Species In Core 1 O-Glycans Deficient Mice, Maria E. Perez-Munoz

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Mucus is one important component of the intestinal mucosal barrier, and loss of its functionality is associated with colitis in humans and mice. Mice deficient in core 1 O-glycans (TM-IEC C1galt1^-/-) display a thinner mucus layer upon mutation of the glycosyltransferase enzyme (C1GALT1) responsible for core 1 O-glycans attachment, thus constituting an experimental model for human Ulcerative Colitis (UC). Under conventional conditions, these mice experience spontaneous inflammation of the colon. However, the exact role of the microbiota in colitis development in these mice has not been systematically investigated.

Aimed to gain insights into the role of …

Enhancement Of The Phytochemical And Fibre Content Of Beef-Patties With Himanthalia Elongata Seaweed, Sabrina Cox, Nissreen Abu-Ghannam

Articles

The effect of adding Himanthalia elongata seaweed (10 - 40% w/w) as a source of antioxidants and dietary fibre on physical, chemical, microbial and sensory traits of cooked beef patties was studied throughout chilled storage. Patties with seaweed showed reduced cooking losses and were nearly 50% more tender as compared to patties without seaweed. Microbiological counts and lipid oxidation were significantly lower in patties containing seaweed (P < 0.05), by day 30 of storage there was no bacterial growth in samples with ≥ 20% seaweed and lipid oxidation levels were low (0.61 mg malondialdehyde/kg of sample). Seaweed incorporation significantly increased the dietary fibre (1.64 g per 100 g fw in 40% seaweed-patties), total phenolic content (up to 28.11 mg GAE/100 g fw) and DPPH radical scavenging activity (up to 52.32%) of patties compared to the control. Sensory analysis indicated that the seaweed-patties were accepted by consumers in terms of aroma, appearance, texture and taste. Patties containing 40% seaweed were rated highest in terms of overall acceptability, most likely due to improvement in texture and mouthfeel. Addition of seaweed in the formulation of beef patties leads to the enhancement of the nutritional and technological quality together with an acceptable sensory quality.

Isolation And Partial Characterization Of Bioactive Fucoxanthin From Himanthalia Elongata Brown Seaweed: A Tlc-Based Approach, Gaurav Rajauria, Nissreen Abu-Ghannam

Articles

Seaweeds are important sources of carotenoids, and numerous studies have shown the beneficial effects of these pigments on human health. In the present study, Himanthalia elongata brown seaweed was extracted with a mixture of low polarity solvents, and the crude extract was separated using analytical thin-layer chromatography (TLC).The separated compounds were tested for their potential antioxidant capacity and antimicrobial activity against Listeria monocytogenes bacteria using TLC bioautography approach. For bio-autography, the coloured band on TLC chromatogram was visualized after spraying with DPPH and triphenyltetrazolium chloride reagents which screen antioxidant and antimicrobial compounds, respectively, and only one active compound was screened …

Food Defense Among Meat Processing And Food Service Establishments In Kentucky, Morgan Webb-Yeates

Masters Theses & Specialist Projects

Agroterrorism is the deliberate introduction of a plant or animal disease with the
goal of causing fear, economic instability, illness, or death. After the 2002 terrorist
attacks on the World Trade Center, the security of the food supply is of increasing
concern to the United States. A major incidence of agroterrorism or food tampering would have far reaching impacts on the economy and public health. The first objective of this project was to determine knowledge and concern of agroterrorism in meat processing facilities in Kentucky, and to determine knowledge and concern of food tampering and food defense in food service …

Physio-Chemical And Sensory Properties Of A Nutrient-Fortified Extruded Product, Tajudini Lassissi Akande

Graduate Theses and Dissertations

Protein malnutrition is responsible for half the deaths of children under the age of five each year in developing countries. More than 4%, 26%, and 70% of children with protein malnutrition live in Latin America/the Caribbean, Africa, and Asia, respectively. The objective of this research was to develop a novel snack made with millet, black eye bean (from Niger Republic), and rice flour fortified with soybean meal protein using extrusion technology. Proximate analysis of the four flours was carried out to determine their chemical composition. Central composite design (CCD) was used to obtain best extrusion conditions to develop a protein-enriched …

Development Of A Predictive Modeling System For Validation Of The Cumulative Mirobial Inactivation Of The Salmonellae In Pepperoni Utilizing A Non-Pathogenic Surrogate Microorganism (Enterococcus Faecalis), Scott Donald Stillwell

Graduate Theses and Dissertations

Salmonellosis is the most frequently occurring bacterial foodborne illness in the United States and the human case rate has not improved for the past two decades. The federal agency responsible for oversight of meat and poultry processors has announced the intent to extend existing pathogen reduction performance standards for Salmonella spp. to cover all classes of products including fermented sausages that are currently produced under HACCP plans that are validated for control of Escherichia coli O157:H7. The proposed regulatory modifications will require processors to revalidate HACCP plan controls to achieve either a 6.5 or a 7.0 log10 inactivation of the …

A Single Point Mutation In The Listerial Betl Sigma(A)-Dependent Promoter Leads To Improved Osmo- And Chill-Tolerance And A Morphological Shift At Elevated Osmolarity, Ronald F. Hoffman, Susan Mclernon, Audrey Feeney, Colin Hill, Roy D. Sleator

Department of Biological Sciences Publications

Betaine uptake in Listeria monocytogenes is mediated by three independent transport systems, the simplest of which in genetic terms is the secondary transporter BetL. Using a random mutagenesis approach, based on the E. coli XL1 Red mutator strain, we identified a single point mutation in a putative promoter region upstream of the BetL coding region which leads to a significant increase in betL transcript levels under osmo- and chill-stress conditions and a concomitant increase in stress tolerance. Furthermore, the mutation appears to counter the heretofore unreported “twisted” cell morphology observed for L. monocytogenes grown at elevated osmolarities in tryptone soy …

Aqueous Extract Of Nigella Sativa Seeds Suppresses Testicular Steroidogenesis In Mice Leydig Cells In Vitro., 5sheikh A. Saeed, Naheed Anwar, Qaiser Jabeen, Anwar Hassan Gilani

Department of Biological & Biomedical Sciences

10ABSTRACT 11Nigella sativa (black seed) is an important medicinal herb with folkloric use in wide range of diseases. It is 12well studied for its biological activities. However, there is limited information regarding its effect on the 13male reproductive system. This study describes the effect of the aqueous extract of N. sativa (NSE) on 14 testicular steroidogenesis from mice Leydig cells in vitro. Mice testicular cells were incubated in a media 15 containing either no treatment or NSE or LH alone or combination of LH and NSE. Incubations were 16 carried out for three hours in a shaking water bath at …

Innovative Food Product Development Using Molecular Gastronomy: A Focus On Flavour And Sensory Evaluation, Mark Traynor

Doctoral

The primary goal of this research was to develop novel ice cream products using the principles of molecular gastronomy. An ice cream model system (emulsion) was developed, in which the effects of ingredient levels on stability and formation were investigated and optimised using Response Surface Methodology (RSM). Two characteristic volatiles of banana (isoamyl acetate and furfuryl acetate) were added to the optimised emulsion, and their headspace emission was quantified using Solid Phase Microextraction with Gas Chromatography Mass Spectrometry. RSM was used to investigate the main and interactive effects of ingredient, salt and pH levels on the headspace emission of these …

Optimization Of Fermentation Conditions For The Utilization Of Brewing Waste To Develop A Nutraceutical Rich Liquid Product, Shilpi Gupta, Amit Jaiswal, Nissreen Abu-Ghannam

Articles

Utilization of brewers’ spent grain (BSG), for the development of a fermented liquid product rich in value-added phenolic compounds was investigated. Changes in and liberation of phenolic compounds and antioxidant activity during fermentation of BSG was studied. The effect of various particle size (PS), solid liquid (SL) ratio, fermentation time and rotation speed was optimized using response surface methodology (RSM) for the purpose of improving bacterial growth and the enhancement in the release of polyphenolic compounds. Contour maps generated using the response surface equation showed that the experimental variables significantly affected the response. A production of 10.4 log cfu/ml, 2.95 …

Utilisation Of Spent Dairy Yeast Kluyveromyces Marxianus For The Production Of Flavoured Yeast Extracts., Brendan Mccarra

Theses

Spent dairy yeast Kluyveromyces marxianus (SDYK), a by-product of whey to ethanol fermentations, was investigated as a natural biomass source for the production of alternative flavoured yeast extracts. SDYK which was characterised by a high protein content (55.3% (w/w) ± 0.8) and comparable levels of flavor enhancing amino acids to that of S. cerevisiae was prepared for induced autolysis at different pH values in the presence of inductors sodium chloride and the proteolytic enzyme papain. An induced autolysis process was developed for the production of flavoured yeast extracts in which pH and autolytic treatment applied were found to have a …

Antilisterial Characteristics Of Volatile Essential Oils, Leeann L. Slaughter

Theses and Dissertations--Animal and Food Sciences

This study explored the in vitro and in situ antilisterial inhibitory activity of 16 essential oils during indirect exposure: Spanish Basil oil (Ocimum basilicum), Bay oil (Pimenta racemosa), Italian Bergamot oil (Citrus bergamia), Roman Chamomile oil (Anthemis nobilis), Sir Lanka Cinnamon oil (Cinnamomum zeylanicum), Citral, Clove Bud oil (Syzygium aromaticum), Cumin Seed oil (cuminum cyminum), Eucalyptus oil (Eucalyptus globulus), Eugenol, Geranium extract (Pelargonium graveolens), Marjoram oil (Origanum majorana), Neroli extract (Citrus aurantium), Peppermint oil (Mentha piperita L.), …

The Effect Of Non-Thermal Processing Technologies On Microbial Inactivation: An Investigation Into Sub-Lethal Injury Of Escherichia Coli And Pseudomonas Fluorescens, Rachel Halpin, L. Duffy, O. Cregenzán-Alberti,, J.G Lyng, F. Noci

Articles

In recent years, there has been an increased interest in food processing technologies that could lessen the thermal impact on food products. In the present study, thermosonication (TS) and pulsed electric fields (PEF), applied individually or in combination (TS/PEF), were investigated to determine their effects on inactivation and sub-lethal injury of Pseudomonas fluorescens and Escherichia coli. TS was applied at a low (L) and high (H) wave amplitude (18.6 μm and 27.9 μm, respectively), while PEF was applied at a low and high electrical field strength (29 kV cm⁻¹ and 32 kV cm⁻¹, respectively). In addition, …