Life Sciences Commons^™

A Mixed Methods Approach To Context Specific Curriculum Design For Very Small And Small Strawberry Growers In The Southeastern United States, Thomas A. Yeargin

Graduate Theses and Dissertations

Outbreaks of foodborne illness due to fresh produce are a continued threat to both the publichealth and the economy in the United States. Though there are many factors which influence the perpetuation of foodborne pathogens, the inability of the food industry to curtail this issue indicates systemic failure of interventions aimed at improving food safety practices. In this dissertation, we detail the efforts made over the past few decades to provide training to food producers and food handlers as well as recommendations that have been made for improvement based on these studies. By borrowing from more advanced fields of study …

To The Window, To The Wall: Improving Environmental Monitoring Protocols, Sarah Jones

Graduate Theses and Dissertations

Detecting microorganisms on environmental surfaces via an environmental monitoring (EM) program is part of a preventive food safety culture. Environmental monitoring should 1) verify that food safety plans are reducing cross-contamination risk from surfaces to food, 2) pinpoint microbial niches, and 3) prevent the transmission of pathogens. Environmental monitoring programs utilize EM tools, such as sponges, to sample food contact and non-food contact surfaces. However, EM tool selection is determined by the individual food firm. This dissertation evaluated and characterized factors influencing EM program effectiveness in the food industry. Specifically, this dissertation focuses on the release of microorganisms from EM …

Evaluating The Accuracy And Quality Of Microgreens Training Materials Available On The Internet: A Content Analysis, Supun Chathuranga Nabadawa Hewage

All Theses

Microgreens are the young, edible seedlings of various vegetables, spices, herbs, and considered as the intermediate stage of sprouts and mature greens, suggesting microgreens may share similar food safety risks with both of these produce. Even though there are no known outbreaks due to contaminated microgreens, multiple product recalls have been reported, indicating food safety risks associated with microgreens should not be underemphasized. A recent national survey of the U.S. microgreens industry reported that almost half of growers (48.3% of 176) learned to grow microgreens by viewing websites and videos on the internet.¹ However, it is unknown whether the …

Contaminated Raw Produce As A Major Source Of Foodborne Salmonellosis, Barisua C. Ikpe

Walden Dissertations and Doctoral Studies

Foodborne pathogens continue to threaten the food supply chain. Salmonellosis is a persistent foodborne pathogen responsible for gastroenteritis, leading to severe illness in children below 5 years of age, adults 65 and older, and people with weakened immune systems. Maryland has rising cases of salmonellosis linked to outbreaks due to consumption of raw or fresh fruits and produce. The purpose of this quantitative study was to determine the association between the development of salmonellosis and the consumption of raw (fresh) produce, demographic and geographic characteristics, type of produce, and seasonal variation in Maryland. The study is based on the theory …

Improving Microbial Safety Of Food Products By Thermal And Non-Thermal Technology And Evaluate The Knowledge Of Antibiotic Resistant Issue Among Local Produce Growers, Wentao Jiang

Graduate Theses, Dissertations, and Problem Reports

Microbial contamination of food products is one of the main transmission routes of disease in the world today, which is responsible for about two-thirds of all food-borne disease outbreaks although the hygiene process was improved recently. Improving microbial safety and implementing a good food management system are important elements to reduce microbial contamination and improve food safety and security. To improve microbial safety, I conducted inactivation studies on food pathogens and further explored antibiotic resistant risks. Initial research evaluated the efficacy of commercial antimicrobials distribution by comparing electrostatic sprayer with conventional sanitization process. The antibiotics applied by electrostatic spraying achieved …

Effect Of Simulated Storage And Distribution On Listeria Innocua Growth In Non-Traditional Salad Ingredients, Emma L. Sandquist

Master's Theses

The fresh-cut produce industry has seen expansive growth in recent years, to meet consumer demand ready-to-eat (RTE) salads have included the use of non-traditional ingredients. Uncommon ingredients include beet greens, kale, broccoli stalk, and Brussels sprouts, since these ingredients have not historically been consumed raw, potential food safety issues should be reassessed. Current processing technologies include produce washes that can reduce microbial levels but do not eradicate all populations. The lack of a kill step in produce processing emphasizes the need to minimize pathogen contamination during production and growth during a product’s shelf life. Listeria monocytogenes, a leading cause …

Evaluation And Impact Of Food Safety Messages In New Media For Trending Recipes: Savory Jam On Youtube, Alison L. Brodt

Electronic Theses and Dissertations

Home canning has been used as a method of food preservation for hundreds of years. The United States has a regulatory agency known as the National Center for Home Food Preservation (NCHFP), which gives guidelines on canning safely to decrease the risk of foodborne illness. The NCHFP provides tips for fruit jams and jellies; however, savory jam is rising in popularity. Savory jam includes jams with a savory main ingredient, such as tomatoes, bacon, onion, or chili peppers. There are currently no guidelines for safe preparation of savory jams. Research is needed to see if recipes for savory jam are …

Elucidating Basis Of Rice Discoloration And Developing Prevention Strategies, Zeinab Mohammadi Shad

Graduate Theses and Dissertations

Economically, discolored rice kernels have less market value, which can seriously impact farm net profit. The reasons for rice discoloration during storage have not been studied extensively and many questions remain. Therefore, the primary goal of this study was to improve understanding of the role and contributions of storage practices on rice quality degradation and discoloration. In this study, three rice cultivars including XL753 (hybrid), Roy J (pureline), and Titan were assessed for changes in quality and microbial kinetics. The rice samples at a high moisture content (MC) of 21% w.b. and a low MC of 16% were stored at …

Microbiota Characterization Of Poultry Processing Systems And Associated Microbiological Sampling Materials Collected At Commercial Processing Facilities, Jennifer A. Wages

Graduate Theses and Dissertations

The poultry industry and associated regulatory bodies use whole bird carcass (WBC) rinsates to evaluate different stages of broiler processing systems for the prevalence of food-borne pathogens, including Salmonella spp. and Campylobacter spp. Within industry and research groups, the same sample collections are enumerated to determine E. coli, Enterobacteriaceae (EB), and Aerobic Plate Count (APC) microorganisms. Analysis of these indicator microorganisms provides numerical data that can be used to demonstrate the effects of specific process control steps where low occurrences of target pathogens hinder the exclusive use of prevalence data. With the utilization of next generation sequencing (NGS), including analysis …

Comparison Of The Kinetic Parameters Of Escherichia Coli 0157:H7, Listeria Monocytogenes And Salmonella Typhimurium Derived From The Baranyi And Huang Models In A Chemically Defined Minimal Medium, Jose Isidro Fuentes

LSU Master's Theses

Microbial growth can be characterized by parameters such as lag time, growth rate, and maximum population density at any specific point of time. Mathematical models that predict microbial growth of foodborne pathogens are increasingly used in the food industry as a viable alternative to traditional methods of microbial enumeration. The Baranyi model has been widely used as the primary model of choice by many authors because of its performance and accuracy. The most recently developed Huang model has been less implemented and few comparisons between the Baranyi and Huang models have been made when modeling pathogenic growth. For this research, …

Improving The Food Safety Of Louisiana Strawberry Industry, Jose L. Brandao Delgado

LSU Doctoral Dissertations

Escherichia coli O157:H7, Salmonella sp., and Listeria monocytogenes have been linked to foodborne outbreaks in produce. The most recent outbreaks in produce have been associated with irrigation water due to infiltration of well water or water run-off from contaminated sources. The Food Safety Modernization Act (FSMA) requires all irrigation water to be safe for use on produce, as a strategy to reduce foodborne illnesses. A surfactant modified zeolite (SMZ) filtration system could provide produce farmers with a sustainable low-cost system for high-quality and safe irrigation water. The objective of this study was to evaluate the effectiveness of hexadecyltrimethylammonium …

Reducing The Risk: Psychological And Technological Approaches For Improving Handwashing Practices In The Foodservice Industry, Jeffrey Allan Clark

Graduate Theses and Dissertations

As Americans are spending greater portions of their dollar on food consumed outside the home, the foodservice industry plays more of an integral part of daily existence compared to previous generations. Given the numerous annual foodborne illness outbreaks that threaten human lives while undermining confidence in the food supply, food safety is a pertinent issue for industry stakeholders, government regulators, and consumers. Food worker handwashing reduces the risk of foodborne illness transmission, yet compliance with this simple behavior is a complex problem. This dissertation addresses, predominantly, the issue of sub-optimal handwashing practices through applying psychology and technology, including wearable computers …

Microbiota Metabolic Product Deoxycholic Acid Prevents Campylobacter Jejuni Chicken Colonization Through Modulating Ceca Anaerobes, Bilal Ali Alrubaye

Graduate Theses and Dissertations

Campylobacter jejuni is a prevalent infectious enteritis mainly foodborne from chickens. Despite of reducing C. jejuni food contamination dramatically decreases campylobacteriosis, few effective approaches are available for the bacterial reduction in chickens. The aim of this study was to use microbial metabolic product deoxycholic acid (DCA) to reduce C. jejuni chicken colonization. Broiler chicks were fed 0 or 1.5 g/kg DCA, lithocholic acid (LCA), or urodeoxycholic acid (UDCA) in diets or orally gavaged with cholic acid (CA, 1.5g/kg body weight). Birds were also transplanted with DCA modulated anaerobes (DCA-Anearo) or aerobes (DCA-Aero). Birds were infected with 109 CFU/bird human clinical …

Aqueous Ozone Inactivation Of Viruses And Bacteria On Biotic And Abiotic Surfaces, Cailin Dawley

Graduate Theses and Dissertations

Produce is susceptible to contamination by foodborne pathogens. Food service establishments utilize sanitizing agents to reduce microbes on produce surfaces. The research objectives were to evaluate the efficacy of aqueous ozone 1) on the inactivation of viruses and bacteria on produce; 2) on the inactivation of viruses on stainless steel; and 3) against viruses in association with bacteria on produce surfaces. For objective 1, Boston bibb lettuce and cherry tomatoes were spot inoculated with a cocktail of viruses (murine norovirus (MNV) and MS2 bacteriophage) or bacteria (Enterobacter cloacae and Bacillus cereus) and washed for 40 min with samples taken every …

Investigating Antibiotic Resistance In Urban Agricultural Environment Using Phenotypic, Genomic, And Metagenomic Tools, Abdullah Ibn Mafiz

Wayne State University Dissertations

Urban agricultural environment can be an important reservoir of antibiotic resistance and have great food safety and public health indications. This study was to investigate antibiotic-resistant bacteria and antibiotic resistance genes in urban agricultural environment using phenotypic, whole genome sequencing, and metagenomic tools. Three urban community gardens from metro Detroit were studied in two phases.

First phase of this study recovered a total of 207 soil bacteria from 41 soil samples collected from an urban agricultural garden. The most prevalent antibiotic resistance phenotypes demonstrated by Gram-negative bacteria was the resistance to ampicillin (94.2%), followed by chloramphenicol (80.0%), cefoxitin (79.5%), gentamicin …

Novel Advancements For Improving Sprout Safety, Kyle S. Landry

Doctoral Dissertations

All varieties of bean sprouts (mung bean, alfalfa, broccoli, and radish) are classified as a “super-food” and are common staples for health conscious consumers. Along with the proposed health benefits, there is also an inherent risk of foodborne illness. When sprouts are cooked, there is little risk of illness. The purpose of this dissertation was to explore novel techniques to minimize or prevent the incidence of foodborne illness associated with the consumption of sprouts. Three areas were investigated: 1) the use of a biocontrol organism, 2) the use of a novel spontaneous carvacrol nanoemulsion, and 3) the influence of the …

Advanced Materials For Rapid Diagnostics In Food, Agriculture And Healthcare, Charmaine K.W. Koo

Doctoral Dissertations

Paper based devices are an emerging trend for micro total analysis systems due to their rapid, sensitive and specific attributes. Lateral flow assays (LFAs), the predecessor of paper-fluidic devices, are developed for many applications which range from nucleic acid and antibody detection to commercial home pregnancy tests. With growing interest in replacing conventional detection methods, multistep assays are needed. These assays require multiple test reagents, therefore, there is a need to control fluid flow for the development of complex paper-based devices. We were able fabricate paper-fluidic platforms where we used electrowetting-on-dielectrics to create valves on paper. With this method, we …

The Food Industry’S Perception Of Economically Motivated Adulteration And Related Risk Factors, Lindsay Colleen Murphy

Masters Theses

The United States of America has numerous safeguards in place to protect our food supply, including federal regulations and the food and beverage industry’s dedication to food safety. One of the issues that the food and beverage industry continuously battles is the prevalence of intentional adulteration. The Food Safety Modernization Act (FSMA) specifically addresses intentional adulteration and its sub-category of economically motivated adulteration (EMA) by requiring all facilities that supply food to the US to assess the vulnerabilities within their operation in order to prevent events that could cause public harm. The purposes of this study are threefold: (1) to …

Foodservice Employees Behaviors And The Presence Of Foodborne-Illness Responsible Microorganisms On Smart Phones, Louise Louise De Gracia, R.D.

Master's Theses and Doctoral Dissertations

As technology advances, smart phone (SP) use is on the rise, including in foodservice establishments. Likewise, the incidence of foodborne-illness in the United States remains high. The presence of disease-responsible microorganisms on health care employees’ mobile phones is well-documented, but little research has examined this relationship concerning foodservice employees’ SPs. Employees (n=50) from a Michigan foodservice establishment were surveyed for their SP use behaviors, and their SPs were swabbed to detect Salmonella, coliforms, and norovirus. Poor hygienic behaviors, such as SP use in the bathroom (75.5%, n=37) were widespread. ServSafe®-certified employees (46%, n=23) were significantly (p=0.041) less likely to use …

Sanitization Effectiveness Of Alkaline-Dissolved Essential Oils As Organic Produce Washing Solutions, Marion Lewis Harness Iii

Masters Theses

Produce is often rinsed immediately post-harvest to remove dirt and debris. Rinse water can be a point of cross-contamination if no antimicrobials are present. While plant essential oils (EOs) are recognized as antimicrobials, their hydrophobicity makes them difficult to implement in rinsing solutions. In this study, the efficacy of emulsified EOs were examined against Salmonella on the surface of cherry tomatoes and Escherichia coli O157:H7 on the surface of baby spinach. Contaminated produce samples were rinsed in an emulsions of clove bud oil or thyme oil at 0.2 and 0.5% (v/v), as well as free chlorine at 200 ppm and …

Acanthamoeba Spp. As Reservoirs For Transmission Of Norovirus, Tun-Yun Hsueh

Graduate Theses and Dissertations

Human noroviruses (HuNoV) are the most common cause of foodborne disease outbreaks in the United States and the most common food commodities implicated in HuNoV outbreaks are leafy greens; however, the vehicle of transmission and point of contamination are often unknown. Here, we hypothesize that common free-living amoebae (FLA) ubiquitous in the environment may act as reservoirs of HuNoV and facilitate the transmission of these pathogens to fresh produce. The objective of this research was to first evaluate the interaction/association between HuNoV surrogates and Acanthamoeba by incubating them together and analyzing virus titer associated with amoeba through an 8 day …

Enhancement Of Antimicrobial Activity Of Naturally Occuring Phenolic Compounds By Nano-Particle Mediated Delivery Against Listeria Monocytogenes, Escherichia Coli O157:H7, And Salmonella Typhimurium, Madhuram Ravichandran

Graduate Theses and Dissertations

Food-borne illnesses are of major concern in the U.S. and worldwide. Salmonella,Listeria,E. coli O157:H7 continue to be some of the major foodborne pathogens. Recurring recalls due to these pathogens demand critical antimicrobial strategies to decontaminate the food through its procession from farm to fork. In our study, we combined the effectiveness of naturally occurring phenolic compounds individually, with/ without ethylenediamine tetraacetic acid (EDTA) and/or Nisin and nanoparticle delivery to improve the antimicrobial potential of the compounds against Listeria monocytogenes (L.m.), Salmonella Typhimurium (S.T.), and Escherichia coli O157:H7 (E.c.), in brain …

Chitosan Reduces Enteric Colonization Of Campylobacter In Young Chickens, But Not On Post-Harvest Chicken Skin Samples, Hanna Royce Arambel

Graduate Theses and Dissertations

Worldwide, Campylobacter is one of the leading causes of foodborne bacterial gastroenteritis causing an estimated 1.3 million infections in the United States alone. Consumption and/or cross-contamination of raw or undercooked poultry products have been linked as the most common source of Campylobacter infection, making the poultry industry a target for Campylobacter reduction strategies. Campylobacter is prevalent in most poultry flocks in the United States, with as many as 90% of flocks Campylobacter-positive at the time of slaughter. It is estimated that a reduction of Campylobacter in poultry would greatly reduce the risk of campylobacteriosis in humans. Unfortunately, there are …

Bacterial Recovery, Transfer To Hands And Survival On Restaurant Menus, Ibtehal Alsallaiy

All Theses

Some non-food contact surfaces such as restaurant menus are not routinely cleaned or evaluated for microbial contamination and thus may be a potential contamination risk. The main objectives of this study were to detect bacteria on restaurant menus, test the rate of bacteria transfer from menus to consumers and determine the survival rate of bacteria on the menu surface. Evaluation of samples can 'find' that menus harbored detectable levels of aerobic organisms and Staphylococcus spp. The average mean of Total Plate count (TPC) was 28 CFU/15cm2 per sampling area during busy periods and 15 CFU/15cm2 per sampling area during less …