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Isolation And Identification Of Chlorate-Reducing Hafnia Sp. From Milk, William P. Mccarthy, Meghana Srinivas, Martin Danaher, Christine O'Connor, Tom F. O'Callaghan, Douwe Van Sinderen, John Kenny, John T. Tobin

Articles

Chlorate has become a concern in the food and beverage sector, related to chlorine sanitizers in industrial food production and water treatment. It is of particular concern to regulatory bodies due to the negative health effects of chlorate exposure. This study investigated the fate of chlorate in raw milk and isolated bacterial strains of interest responsible for chlorate breakdown. Unpasteurized milk was demonstrated to have a chlorate-reducing capacity, breaking down enriched chlorate to undetectable levels in 11 days. Further enrichment and isolation using conditions specific to chlorate-reducing bacteria successfully isolated three distinct strains of Hafnia paralvei . Chlorate-reducing bacteria were …

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 The Kitchen Microbiome And Food Safety Behaviors Of Predominantly Low-Income Families, Christina K Carstens, Joelle K Salazar, Shreela V Sharma, Wenyaw Chan, Charles Darkoh

Journal Articles

Bacterial pathogens in the domestic environment present a risk to residents, particularly among susceptible populations. However, the impact of consumer demographic characteristics and food handling methods on kitchen microbiomes is not fully understood. The domestic kitchen bacterial communities of ten predominantly low-income families in Houston, TX, were assessed in conjunction with a cross-sectional food safety survey to evaluate differences in household and surface-specific microbiomes and bacterial foodborne pathogen presence. Three kitchen surfaces within each household, including the sink drain, the refrigerator handle, and the counter, were environmentally sampled and metataxonomically evaluated via targeted 16S rRNA sequencing. Disposable dish sponges were …

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, …

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 …

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 …

Research Tools And Their Uses For Determining The Thermal Inactivation Kinetics Of Salmonella In Low-Moisture Foods, Soon Kiat Lau

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

The reputation of low-moisture foods as safe foods has been crumbling over the past decade due to repeated involvement in foodborne illness outbreaks. Although various pasteurization technologies exist, a majority are thermal processes and have not been well-characterized for pasteurizing low-moisture foods. In addition, the nature of a low-moisture food matrix introduces various experimental complications that are not encountered in high-moisture foods. In this dissertation, the development, building instructions, and characterization of various open source tools for studying the inactivation kinetics of microorganisms in low-moisture foods are described. The first tool is the TDT Sandwich, a dry heating device for …

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 …

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 …

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 …

Farm-To-Fork Fresh Produce Food Safety: An Evaluation Of Perceptions, Knowledge, And Implementation Of Good Agriculture Practices In Kentucky, Daniel J. Sinkel

Masters Theses & Specialist Projects

Farmers’ markets have increasingly become a popular venue for purchase of fresh, locally-grown produce, with the number of farmers’ markets in Kentucky reaching an all-time high of 159 in 2016. Good Agriculture Practices (GAPs) is a program created by the USDA’s Agriculture Marketing Service to function as a food safety audit for small-scale fresh produce growers, such as those who sell fresh produce at local farmers’ markets. However, under the provisions of the Food Safety Modernization Act of 2011, small-scale farmers who sell an average of $25,000 in annual fresh produce sales across the span of three years are exempt …

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 …

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 …

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 …

Layer-By-Layer Antimicrobial N-Halamine Polymer Coatings For Food Contact Materials, Luis J. Bastarrachea Gutierrez

Doctoral Dissertations

Cross contamination during food processing represents a risk for public health and financial burden. Surface modification of food contact materials to render them antimicrobial can be effective against such risk. The objective of the present work was to develop antimicrobial coatings with the potential to be applied in a variety of food contact materials. The polymer coatings developed became antimicrobial by incorporation of a type of chlorinated compounds called N-halamines, capable of regenerating their antimicrobial activity. Two layer-by-layer (LbL) assembly surface modification procedures were followed. In the first procedure, bilayers of branched polyethyleneimine (PEI) and poly(acrylic acid) (PAA) were applied …

Amyloid Fibrils: Potential Food Safety Implications, Michael Greger

Michael Greger, MD, FACLM

The demonstration of oral Amyloid-A (AA) fibril transmissibility has raised food safety questions about the consumption of amyloidotic viscera. In a presumed prion-like mechanism, amyloid fibrils have been shown to trigger and accelerate the development of AA amyloidosis in rodent models. The finding of amyloid fibrils in edible avian and mammalian food animal tissues, combined with the inability of cooking temperatures to eliminate their amyloidogenic potential, has led to concerns that products such as pâté de foie gras may activate a reactive systemic amyloidosis in susceptible consumers. Given the ability of amyloid fibrils to cross-seed the formation of chemically heterologous …

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 …

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 …

The Effect Of Chlorine And Ozone In Controlling Microbes On Organically Grown Cilantro And Carrots, Adam Holtz

BioResource and Agricultural Engineering

This senior project investigates the relative efficacy of ozonated water and chlorinated water for the purpose of sanitizing freshly-harvested organic produce. The aim of this study was to assist the Cal Poly Organic Farm in deciding whether or not to invest in an ozone generator. The crops used for testing were grown organically in the same field. Carrots and cilantro were harvested and promptly treated with 5 ppm ozone solution or 25 ppm sodium hypochlorite solution. Carrots were sampled at 0, 7, and 14 days storage to determine microbial populations. Cilantro was similarly tested at 0, 6, and 12 days …

Feed Supplementation With Natural Extracts Of Cranberry And Its Efficacy On Campylobacter Colonization In Poultry, Ann Woo-Ming

Graduate Theses and Dissertations

Campylobacter spp. has been identified as one of the leading causative agents of food borne diarrheal illness. Epidemiological evidence has shown that poultry is the main source for human infection. Poultry are asymptomatic carriers of Campylobacter within their gastrointestinal tract, with colonization levels reaching 106-108 cfu/g cecal content. Surveys of domestic poultry flocks have estimated that approximately 90% of flocks are positive for Campylobacter colonization. Risk assessment studies have determined that by reducing levels of Campylobacter colonization during rearing, incidences of human infection will be significantly reduced. Currently there are no consistently effective treatments to eliminate Campylobacter from poultry flocks. …

Sanitation Assessment Of Food Contact Surfaces And Lethality Of Moist Heat And A Disinfectant Against Listeria Strains Inoculated On Deli Slicer Components, Sabelo Muzikayise Masuku

Graduate Theses and Dissertations

The overall objectives of this study were to: evaluate the efficacy of different cleaning cloth types and cloth-disinfectant combinations in reducing food contact surface contamination to acceptable levels; determine the optimum moist heat and moist heat + sanitizer treatments that can significantly reduce the number of Listeria strains on deli slicer components; and investigate if the moist heat treatment used in this study induced the viable-but-non-culturable (VBNC) state in Listeria cells. The efficacy of wiping cloths was measured using ATP-bioluminescence and total plate count methods using four different wiping cloths and silver dihydrogen citrate sanitizer on food contact surfaces. The …

Recent Advances In The Application Of Non Thermal Methods For The Prevention Of Salmonella In Foods, Shilpi Gupta, Nissreen Abu-Ghannam

Books/Book Chapters/ Proceedings

Food-borne illness as a result of consumption of foods contaminated with pathogenic bacteria is a world-wide concern. The presence and subsequent growth of micro-organisms in food in addition to improper storage not only results in spoilage but also in a reduction of food quality. The microbiological safety in ready to eat products is a cause of big concern not only for the consumers and food industries but also for the regulatory agencies. The number of documented outbreaks of foodborne diseases has increased in the last decade with Salmonella spp., Listeria monocytogenes and Escherichia coli being responsible for the largest number …

Investigating The Effectiveness Of Malic Acid, Nisin, And Grape Seed Extract Incorporated Into Whey-Protein Coatings To Inhibit The Growth Of Listeria Monocytogenes On Ready-To-Eat Poultry, Amanda Bettasso, Navam Hettiarachychy, Vidya Chitturi, Michael Johnson

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The ability to control growth of Listeria monocytogenes on ready-to-eat poultry products with the antimicrobials nisin, malic acid, and grape seed extract incorporated into whey-protein coatings was evaluated. The antimicrobials were incorporated into the coating solution alone and in combinations. One gram pieces of turkey frankfurters were coated with the coating solutions and then inoculated with L. monocytogenes and stored at 4°C for 28 days. The inhibitory effect of the coatings on turkey frankfurter pieces was evaluated on d 0, 7, 14, 21, and 28. Coatings containing 2% malic acid, 3% malic acid, and the combination of nisin (6,000 IU/g) …

Where Are The Risks In Food And What Can You Do About Them?, Charlotte P. Brennand Ph. D.

Archived Food and Health Publications

Publication discusses dangers in foods and how to safely handle and prepare food.