Life Sciences Commons^™

Environmental Health Assessments For Foodborne Illness Outbreaks In The United States From 2017- 2019, Alyssa Shontel Woods

Walden Dissertations and Doctoral Studies

Individual cases of foodborne illness can lead to outbreaks that result in severe morbidity and fatality. As the United States’ food scene continues to evolve and diversify, there is a need to consider cultural variations and how they may affect food safety practices. This quantitative study, based on the National Environmental Assessment Reporting System (NEARS) data, grounded in the socio-ecological model, examined the prevalence and factors associated with salmonella outbreaks in ethnic versus non-ethnic food service establishments (FSEs) in the U.S. from 2017 to 2019. The research questions involved understanding the relationship between the primary language spoken, food safety training, …

Thermal Inactivation Of Salmonella, Escherichia Coli, And Enterococcus Faecium Nrrl B-2354 In Pasta Matrices, Kristi Shannon Gowans

Theses and Dissertations

Limited data are currently available characterizing the thermal resistance of foodborne pathogens in semolina flour and intermediate pasta matrices representative of commercial conditions during mixing, extrusion, and drying. These data are essential to pasta producers seeking to be compliant with federal regulations since Salmonella spp. and Escherichia coli demonstrate survival in wheat flour and dried pasta products. This study investigated the heat resistance of Salmonella, pathogenic E. coli, and E. faecium NRRL B-2354 in raw semolina flour and partially dried pasta intermediates via thermal death time (TDT) studies. This study also assessed the appropriateness of E. faecium NRRL B-2354 as …

Isothermal Inactivation Studies Of Listeria Monocytogenes, Salmonella, And Enterococcus Faecium Nrrl B-2354 In Almond, Peanut, And Sunflower Butters, Ruo Fen Liao

Theses and Dissertations

Vegetative, non-sporeforming foodborne pathogens show notable survival and uncanny thermotolerance in low water activity (aw) foods. Controlled studies on Listeria monocytogenes, Salmonella spp., and Enterococcus faecium NRRL B-2354 (a Salmonella surrogate) in a variety of food matrices support thermal process validation studies required to achieve global food safety objectives. In this study, we determined and compared thermal inactivation rates using independent six-strain cocktails of pathogens in three plant-based butters. Direct determinations of decimal reduction times (D-values) for L. monocytogenes, Salmonella, and E. faecium, in corresponding butters were inoculated using peanut oil, almond oil, or sunflower oil. Thermal Death Time (TDT) …

Improving Nutrition And Food Safety Knowledge Of Small-Scale Fish Processors In Delta State, Nigeria, Grace Adeola Adegoye

Theses and Dissertations

Introduction: Fish is an affordable animal source food that provides nutrition and serves as a source of income for many people especially women in Nigeria. Smoking and sun drying are the processing methods in practice that expose the fish products to possible contaminants which may consequentially negate their nutritive value.

Aim: To improve the knowledge of fish processors on nutrition and safe fish handling.

Methodology: A 3-day participatory training was organized to train 122 fish processors, 95 women, and 25 men. The training was conducted in the three senatorial districts in Delta State, Nigeria. Knowledge was assessed using the pre …

Physical And Microbiological Characteristics Of Pickled Eggs From Japanese Quail (Coturnix Coturnix Japonica) Of The Pharaoh Variety, Adair Hoover

All Theses

The quality and microbiological characteristics of quail eggs were evaluated after eggs were pickled in different vinegar brine solutions. Pickling food in vinegar is one of the oldest preservation methods; however, little research has been conducted on pickled quail eggs. Commercial quail eggs obtained from a local producer were boiled, peeled, and placed into various pickling solutions and held for 24 or 48 hours at room temperature. After the holding period, eggs were removed from the solutions, weighed, and tested for pH, water activity, texture, and color. A second experiment was conducted to determine the effects of various pickling solutions …

Detection Of Mycotoxins Using Surface-Enhanced Raman Spectroscopy, Lourdes B. Martinez Rojas

Doctoral Dissertations

Mycotoxins are toxic metabolites produced by fungus that can be parasites or saprophytes of crops or livestock forage. Consumer demand for plant-based foods and interest in animal-based foods originating from animals fed plant-based feed has been on the rise. Therefore, monitoring mycotoxins occurring in the food supply is more critical than ever. The goal of this project is to improve surface-enhanced Raman spectroscopy’s (SERS) ability to identify and detect mycotoxins using label-free SERS substrates. Two simple approaches were designed to enhance the detection of mycotoxins produced by the Aspergillus and Penicillium genera, ochratoxin A and aflatoxin B1. Ochratoxin A was …

Evaluation Of Food Safety Practices At Louisiana Summer Feeding Sites And Food Safety Communication Via Social Media During Crises, Peyton E. Haynes

LSU Master's Theses

The United States Department of Agriculture’s Summer Food Service Program (SFSP) provided children under the age of 18 in low-income areas 145 million free meals in 2018 through summer feeding sites. Food safety issues arise for Louisiana feeding sites due to time-temperature controlled foods served, weather patterns in Louisiana, seasonal staff and short operation time, and lack of equipment. The purpose of this study was to assess food safety practices at Louisiana feeding sites through observational study with intention to compare food practices at institutional and noninstitutional sites. A rubric following USDA food safety guidelines based on categories: hot holding, …

High Throughput Analysis To Study Emerging Pollutants And Nanoparticle Fate In Biological Systems, Xiaolong He

Doctoral Dissertations

”The increasing applications of emerging and fugitive contaminants (EFCs) and engineered nanoparticles (ENPs) attract significant research interest for their potential risks to human health and the environment. In order to assess the health risks of these emerging contaminants, rapid and reliable analytical methods to measure the concentrations and fates of these contaminants are imperative. This dissertation focuses on the developments of advanced analytical methods and their applications to study those emerging contaminants in crop plant and simulated gastric fluid (SGF). Three types of mass spectrometry based methodologies have been developed, one is freeze-thaw/centrifugation extraction followed by high performance liquid chromatography …

The Use Of Inorganic And Organic Acids As Short Duration Antimicrobial Dips On Mitigating Pathogens Present On Commercial Chicken During Peri-Harvest, Dana Kristen Dittoe

Graduate Theses and Dissertations

With poultry being the most consumed meat in the United States, poultry processors must provide consumers with safe, wholesome products. As a consequence, poultry processors are faced with the challenge of reducing the presence of foodborne pathogens such as Salmonella spp. and Campylobacter jejuni among raw poultry products. Though multi-hurdle approaches using antimicrobials are placed throughout processing to reduce these pathogens, Salmonella and C. jejuni still persist among raw poultry. Thus, it was the objective of the current dissertation to investigate various antimicrobials, organic and inorganic acids, as short duration dips and sprays as means to reduce common pathogens (Salmonella, …

Fate And Dissemination Of Salmonella Reading In Market-Age Turkeys At Processing Using Oral Gavage Challenge Model, Aaron Ashcraft

Graduate Theses and Dissertations

This study aimed to evaluate the fate and dissemination of Salmonella Reading (SR) in market-age turkeys using an oral gavage challenge model. One hundred twenty-eight-week-old commercial turkey hens were moved from commercial production to research facilities. Upon arrival, a combination of enrofloxacin, 10 mg/kg, and florfenicol, 20 mg/kg, were orally administered sequentially before comingled placement on fresh pine shavings. Turkeys were challenged with 108 cfu SR by oral gavage on days 4 and 7 post-placement. Subsets were subjected to simulated commercial processing on days 14 (n=40), 21 (n=40) and 28 (n=32) post-placement (corresponding to 10, 11, and 12 weeks of …

Effects Of Salt And Garlic Concentration On The Microbial Safety, Biochemical Properties, And Sensory Acceptance Of Spontaneously Fermented Beet Kvass, Abigail Hing

Electronic Theses and Dissertations

Fermentation is the process by which primarily lactic acid bacteria (LAB), an environmentally ubiquitous group of organisms, convert carbohydrates into several byproducts, including acid, ethanol and/or gas. Often these resulting byproducts create desirable foods with unique flavor attributes and an increased inherent safety due to acidification. Vegetables such as red beetroot are suitable commodities for fermentation, due to abundant nutrient sources to sustain the LAB population. However, sufficient growth of LAB may lead to the production of harmful biogenic amines, specifically histamine and tyramine which can cause an allergic reaction and poisoning at high levels. Additionally, red beetroot is grown …

Isothermal Inactivation Of Salmonella, Listeria Monocytogenes, And Enterococcus Faecium Nrrl-B 2354 In Peanut Butter, Powder Infant Formula, And Wheat Flour, Adam Robert Quinn

Theses and Dissertations

Pathogens in low-moisture foods are an emerging food safety concern due to increased survival and thermotolerance in matrices with low water activity. However, limited data is publicly available for the thermotolerance of Listeria monocytogenes, Salmonella spp., and Enterococcus faecium NRRL B-2354 (a Salmonella surrogate). The aims of this study were to identify differences in thermal inactivation rates between these organisms in three different low-moisture foods. Three model low-moisture foods (peanut butter, powder infant formula, and wheat flour) were inoculated with either E. faecium, a Salmonella spp. cocktail, or a L. monocytogenes cocktail using a dry inoculation method for a total …

Thermal Inactivation Of Bacterial Pathogens And Fungal Spores Under Post-Process Contamination Scenarios In Maple Syrup Processing, Maria Fiore

Electronic Theses and Dissertations

Maple syrup is produced by the extensive thermal evaporation of maple sap traditionally collected from the Acer saccharum tree and other maple varietals. The resulting low water activity product (Aw < 0.85) is classified by the FDA as a low risk food commodity, due to the moisture limitations which inhibit the growth of pathogenic microorganisms. However, recent outbreaks associated with other designated low risk products, including peanut butter and wheat flour, now challenge the current understanding of factors required to induce human illness. Among the most notorious bacterial pathogens, as few as ten bacterial cells, have been cited to cause infection. In addition to bacteria-based risks, fungal contaminants have also been noted to jeopardize safety due to the potential for mycotoxin production, penetrating beyond the immediate product surface.

The extensive heating process required to produce syrup from sap is sufficient to eradicate the majority of present microflora. However, post-process contamination scenarios, which are augmented by producer behaviors, can introduce microorganisms into the finished product. Among these risk factors include direct product contamination due to insufficient heating temperatures, or contamination of bottles, as a result of improper container storage. Therefore, the objectives of this work are to (i) determine …

Assessment Of Protein Quality, Lipid Metabolism, Hepatic Transcriptome And Safety Of A Silver Carp (Hypophthalmichthys Molitrix) Derived Sarcoplasmic Protein Powder., Derek Cole Warren

Graduate Theses, Dissertations, and Problem Reports

Fishery resources are currently operating either near optimal yield or at levels with elevated risk for fish stock depletion. A solution for overcoming limitations of natural fish resources is through utilization of less desirable fish species and fish processing by-products. Water-soluble sarcoplasm proteins consist of 25 – 30% of protein in carp, are lost in wash water during processing and can be recovered and freeze-dried to produce a protein-rich powder (CSP). The objective of this project was to evaluate the protein quality and safety of CSP, assess diets consisting of CSP or commercial milk proteins effects on lipid metabolism, and …

Evaluation Of Salmonella Enteritidis And Escherichia Coli O157:H7 Volatile Organic Compound Analysis For Food Safety Monitoring: A Preliminary Study, Jessica E. Lemley

Graduate Theses, Dissertations, and Problem Reports

Food borne illness has the potential to impact every point of production from producers to consumers. Food product recalls are common due to the presence of food borne illness causing bacteria. Detection of volatile organic compounds (VOC) have the potential to reduce the number of illnesses and recalls through application of additional monitoring of food products like those most commonly recalled. The objective of this research was to 1) explore the use of closed-loop headspace analysis coupled with gas chromatography-mass spectrometry (GC-MS) on food borne illness causing bacteria and 2) examine the VOC profile of Escherichia coli serotype O157:H7 in …

Identification Of High-Risk Food Coping Strategies Of Maine Food Pantry Clients, Kathryn Cutting

Electronic Theses and Dissertations

Food coping strategies are strategies adopted by individuals in order to obtain enough food for themselves and their family. Food coping strategies can range from using coupons (couponing) and buying in bulk to skipping meals and stealing food. Although not all strategies are considered to be high risk, all strategies should be accounted for so that nutrition education programming caters to strategies that individuals are employing. This topic has not been widely researched in the United States. The purpose of this study was to identify common food coping strategies of food pantry clients across nine counties in Maine, explore identified …

Characterization Of Bacterial Isolates Obtained From Commercial Poultry Feed And Retail Food Using Whole Genome Sequence Analysis And Selected Biochemical Tests, Elena George Olson

Electronic Theses & Dissertations

The goals of this study is two-fold. The first part investigates bacterial isolates from commercial poultry feed and the second part deals with bacterial isolates recovered from retail food. In order to reduce pathogen contamination in poultry products identification of overall microbial populations in poultry production processing steps have always been considered an important monitoring tool for assessing sanitizer effectiveness and the corresponding responses of bacteria load levels on poultry carcasses. Bacterial isolates recovered from corn-based chicken feed were purified on aerobic plate count agar and eleven morphologically different colonies were selected for whole genome sequencing. In this part, the …

Regulatory Disclosure Policies And Potential Induced Changes In Behavior: An Outcome Evaluation Of Santa Clara County’S Enhanced Food Safety Program Elements, Christian Cruz

Master's Projects

Despite countless advances in food microbiology and public health regulations, foodborne illness continues to be a major strain on public health outcomes and a costly economic burden. In the United States, many agencies are responsible for ensuring the quality of food, both domestically produced and imported. States and localities are delegated the responsibility of identifying and ensuring sound practices in the latter stages of the food production process, namely the retail distribution of food products to consumers.

Regulatory policies across the nation have only recently incorporated the evidenced-based principles of hazard risk management (Law, 2003). Still, food-related acute gastrointestinal illnesses …

An Environmental Approach To Food Safety Assessment Using Artisan Cheese And Fresh Produce As Model Systems, Marie Limoges

Graduate College Dissertations and Theses

This dissertation examined recently issued regulatory standards using cheese and produce as model systems. FDA's 2015 Domestic and Imported Cheese and Cheese Products Compliance Program Guidelines (CPG) E. coli standards on cheese safety, and the extent to which these standards affect domestic and imported cheese commerce, was assessed. Results from FDA's Domestic and Imported Cheese Compliance Program for samples collected between January 1, 2004 and December 31, 2006 were analyzed. Of 3,007 cheese samples tested for non-toxigenic E. coli, 76% (2,300) of samples exceeded 10/g, FDA's target for regulatory activity. In cheese samples containing E. coli levels of 10/g and …

Hospital And Meat Associated Staphylococcus Aureus And Their Biofilm Characteristics, Trevor Michael Wienclaw

Theses and Dissertations

Biofilm phenotypes were studied in 32 Staphylococcus aureus strains isolated from store-bought meats and 22 from diseased patients in hospitals. Of the meat-associated strains, 21 were methicillin-resistant Staphylococcus aureus (MRSA) and 11 were methicillin-susceptible Staphylococcus aureus (MSSA). The hospital-associated strains included 15 MRSAs and 7 MSSAs. We studied the robustness and composition of the biofilms produced by these strains. We found that on average hospital-associated strains form more robust biofilms than meat associated strains. The model often used to describe S. aureus biofilm composition includes two biofilm types defined by the presence or absence of polysaccharide intercellular adhesin (PIA), PIA-dependent …

Three Essays On Food Safety Regulations And International Trade Of Agricultural Products, Jun Ho Seok

Theses and Dissertations--Agricultural Economics

This dissertation investigates food safety regulations and international trade of agricultural products dividing into three aspects: the signalling effect from U.S. strict food safety regulations on U.S. vegetable exports, political determinants of sanitary and photosanitary non-tariff barriers, and the impact of trade barriers on employment in developing countries. In chapter 2, we investigate the impact of high U.S. maximum residue limit (MRL) standards on U.S vegetable exports to 102 countries utilizing the hierarchical model. MRL, which is one of non-tariff barriers with respect to food safety, is applied to home and foreign countries at the same time. Thus, firms in …

Modeling For Thermal Resistance Of Non-O157 Shiga Toxin Producing Escherichia Coli In Ground Beef, Jagpinder S. Brar

Open Access Dissertations

Predictive models in microbiology are used for estimating the growth or survival of microorganism in a set of environmental conditions. A validated predictive model provides an alternative to extensive survival and shelf life studies. In this study, a predictive inactivation model for non-O157 shiga toxin producing Escherichia coli (STEC) in ground beef was developed. Six strains of non-O157 STEC; E. coli O26:H1, E. coli O45:H2, E. coli O103:H2, E. coli O111:H8, E. coli O121:H9, and E. coli O145: nonmotile, has similar pathogenicity as E. coli O157:H7 and can cause serious food borne illnesses. These pathogens are considered as an adulterant …

The Effects Of Using Cinnamon Leaf And Bark Essential Oils On Listeria Monocytogenes (L.M.), Salmonella Typhimurium (S.T.), In Model System, Strawberry Shake And Fresh Celery, And Sensory & Shelf Life Studies, Wafaa Brnawi

Graduate Theses and Dissertations

Essential oils derived from the bark and leaves of the cinnamon plant have long been used as natural preservatives and flavoring agents in different types of foods. In this study, we evaluated the antimicrobial effects of cinnamon essential oils (CEOs), obtained from cinnamon leaf or bark, against two foodborne pathogens i.e., Salmonella Typhimurium (S.T.) and Listeria monocytogenes (L.m.). Two different concentrations of microbial loading were used i.e.,109 and 104, cultured in nutrient media broth, strawberry shakes, and on celery sticks. Both CEOs of leaf and bark at 0.5% and 1% were found to completely inhibit S.T. and L.m., immediately after …

Development Of Bacteriophage Based Detection Technique For Food Safety And Environment Monitoring, Ziyuan Wang

Doctoral Dissertations

Foodborne or waterborne pathogens which are responsible for numerous worldwide outbreaks of disease have caused serious health problems and enormous economic cost. Development of new bacterial detection technologies with high sensitivity and specificity is of great importance for food safety and public health. This has highlighted the significance of developing rapid and effective techniques for pathogen screening. Thus we aim to explore a bacteriophage mediated detection system for foodborne or waterborne bacteria monitoring. Bacteriophage as a novel recognition probe has been applied in various biosensor by immobilizing phage particles on solid sensor surface. They possess high specificity for targeted microorganism …

Enzymatic Digestion Improved Bacteria Separation From Leafy Green Vegetables, Danhui Wang

Masters Theses

An effective and rapid method for the separation of bacteria from food matrix remains a bottleneck for rapid bacteria detection for food safety. Bacteria can strongly attach to the food surface or internalize within the matrix which makes their isolation extremely difficult. Traditional methods of separating bacteria from foods routinely involve stomaching, blending and shaking, however these methods may not be efficient at removing all the bacteria from complex matrices. Here, we investigate the benefits of using enzyme digestion followed by immunomagnetic separation to isolate Salmonella from spinach and lettuce. Enzymatic digestion using pectinase and cellulase was able to break …

Ecological Dynamics In Compost-Amended Soils And The Resulting Effects On Escherichia Coli Survival, Anya Cutler

Graduate College Dissertations and Theses

Escherichia coli (E. coli) are common and typically innocuous copiotrophic bacteria found in the mammalian gut microbiome. However, over the past 30 years, pathogenic E. coli have been responsible for several outbreaks of foodborne illness linked to contaminated produce. The introduction of Escherichia coli to an agricultural soil, via contaminated water, compost, or raw manure, exposes the bacterium to a medley of ecological forces not found in a mammalian gut environment. This study assesses a variety of abiotic and biotic soil factors that influence the ability of an "invasive" copiotrophic coliform bacterium to survive in compost-amended agricultural soil. The study …

Microbial Safety, Shelf Life Stability, Quality Preservation, And Consumer Acceptance Of Vacuum-Infused, Irradiated Chicken Breast Meat Treated With Natural Plant Extracts And Organic Acids, Kenneth Franklin Over

Graduate Theses and Dissertations

Contamination of poultry products with food borne pathogens is a consistently recurring problem in the United States and the world. Recalls associated with chicken contamination are responsible for considerable economic losses to the poultry industry. Many decontamination steps are currently in place to reduce the likelihood of contaminated products reaching the consumer, but despite these safeguards, contamination events are still uncomfortably frequent. Irradiation is a safe and effective means of ensuring the safety of both ready-to-cook and ready-to-eat poultry but is not utilized in the United States. This is due, in part, to certain irradiation dose-dependent quality characteristic defects associated …

Reduction Of Campylobacter Jejuni On Chicken Wingettes By Treatment With Caprylic Acid, Chitosan Or Protective Cultures Of Lactobacillus Spp., Ann Nicole Woo-Ming

Graduate Theses and Dissertations

Poultry is one of the main sources of protein in the United States and in 2014 Americans ate approximately 100 lbs per person. However, consumption of poultry products is strongly associated with foodborne illness from Campylobacter. In the first study, chitosan, caprylic acid and their combination were evaluated as a coating treatment for the reduction of Campylobacter jejuni on poultry products. For the initial screening trials, chitosan of three different molecular weights (15-50 kDa, 190-310 kDa and 400-600 kDa) was evaluated at three concentrations (0.5%, 1.0%, 2.0%) and separately, caprylic acid was tested at 0.5%, 1.0% and 2.0% using chicken …

Phenotypic And Functional Genomics Analyses Of Salmonella For Food Safety Applications, Turki Dawoud

Graduate Theses and Dissertations

Non-typhoidal Salmonella species have been major foodborne zoonotic pathogens causing serious problems in public health and food industry for several decades. Numerous Salmonella species have frequently been associated with different food commodities mainly poultry meat, eggs, and their products. This dissertation begins with a literature reviews discussing many aspects of Salmonella generally; and subsequently focused on two serotypes, Salmonella Enteritidis and S. Typhimurium as they are at the top of all other serovars responsible for most illness cases and outbreaks. In addition, some Salmonella strains have exhibited their ability to tolerate and survive many food processing treatments. We can divide …

Effective Education On Consumers' Food Safety Knowledge, Perceptions, And Behaviors At Local Area Farmers' Markets, Molly Louise Albin

Masters Theses

Although extensive research has been conducted to understand consumers’ knowledge of food safety risks, there is a lack of research on consumers’ knowledge, perceptions, and behaviors towards risks associated with locally grown, processed, and manufactured foods sold at farmers’ markets. Recently, there has been a movement toward purchasing local foods to support local economies, out of concern for food miles, or because of a perception of higher quality goods. In Tennessee, the number of farmers’ markets has doubled in five years. Furthermore, previous research determined food safety education is most effective if developed with input from the target audience. The …