Food Microbiology Commons^™

Surrogate-Based Approaches For Evaluating Post-Harvest Food Safety Interventions In Fresh Produce, Md Shafiul Islam Rion

Graduate Theses, Dissertations, and Problem Reports (ETD)

Pathogenic bacteria are still a threat to human beings worldwide as their presence is often unknown even if they are already present in fresh produces. This in turn resulted in several outbreaks and recalls across the United States. This dissertation investigated the survival of pathogenic bacteria and their potential non-pathogenic surrogates after antimicrobial interventions in different modes of applications on the surface of cantaloupes, butternut squash, and fresh cilantro. In the first study, peroxyacetic acid (PAA) was applied in three separate doses on nalidixic acid resistant Salmonella Typhimurium, Listeria monocytogenes, Enterococcus faecium, and Listeria innocua inoculated cantaloupe surfaces …

Inactivation Kinetics Of Escherichia Coli And Listeria Monocytogenes In Edible Insects, Precious Aduloju

Graduate Theses, Dissertations, and Problem Reports (ETD)

Edible insects are emerging as sustainable and nutritious alternatives to conventional protein sources. However, concerns about food safety, particularly the presence of pathogenic bacteria such as Escherichia coli and Listeria monocytogenes, remain a barrier to consumer acceptance and industrial use. This study evaluated the effectiveness of thermal processing in inactivating E. coli, L. monocytogenes, and their non-pathogenic surrogates (E. coli JM109 and Listeria innocua) in both fresh and dehydrated forms of Tenebrio molitor (mealworm) and Acheta domesticus (cricket). It also evaluated the influence of insect species, moisture content, and temperature on microbial inactivation. A microbial challenge …

Anti-Listeria Of H2o2-Peroxyacetic Acid Anti-Listeria Efficacy Of A Hydrogen Peroxide-Peroxyacetic Acid Mixer In Bacterial Buffered Solution And On Bell Peppers, Peighton Denae Foster

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study aims to 1) evaluate the efficacy of H₂O₂-peroxyacetic acid (PAA) mixer to inactivate Listeria monocytogenes in 0.1% buffered-peptone-water; 2) evaluate the reduction and mitigation of cross-contamination on peppers. For the study-1, aliquots of 1.0-ml mixer solutions (0.25, 0.50 and 0.84%) were added to the first 3-well of 8-strip-deep-well microplates. Then, the 0.1 ml of 10-fold dilution the Nalidixic-acid-resistant (NaL) L. monocytogenes was added and mixed immediately with a multichannel pipette. After exposure for 0, 5, 15, 30, and up to 120-s, 1 ml of 2×D/E neutralized solution was added to terminate the reaction followed …

Impacts Of Temperature And Salt Concentrations For Thermal Inactivation Of Salmonella In Moisture Enhanced Reconstructed Chicken Patties, Alik D. Browning

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this experiment is to determine the thermal kinetic parameters of Salmonella in moisture-enhanced, reconstructed ground chicken patties as affected by temperatures and salt concentrations. Salmonella is responsible for 35% of the foodborne illnesses associated with poultry products (Batz et al., 2011). Nonintact reconstructed chicken meat is mixed with brine solutions containing various salt and polyphosphate concentrations to increase water-holding capacity, decrease cooking losses, improve sensory tasting scores, and maintain the good quality of completed chicken products (Gill et al., 2004). Increasing salt concentrations within meats can increase the thermal inactivation of pathogens. In this study, Salmonella Typhimurium …

Analysis Of Experimental Antimicrobial Prevention Strategies Against Microbial Contamination Of Locally Harvested Poultry And Produce In West Virginia, Rebecca Breanne Stearns

Graduate Theses, Dissertations, and Problem Reports (ETD)

Fresh produce and poultry have been associated with several foodborne illness outbreaks. Strategies to mitigate these risks are a much-needed research priority; therefore, five experiments were conducted to analyze pathogen cross-contamination capabilities on produce and poultry. Microbial contamination prevention and reduction strategies were also studied.

In Chapter Two, three antimicrobial delivery methods in combination with increasing concentrations of hydrogen peroxide-peroxyacetic acid (H₂O₂-PAA) (0.05-0.25 ml/dL) were compared to evaluate their ability to reduce and prevent cross-contamination of Listeria monocytogenes (L. monocytogenes) and Listeria innocua (L. innocua) on inoculated apples. Apples have been …

Evaluate A Mixer Of Hydrogen Peroxide And Peroxyacetic Acid To Mitigate Microbial Cross-Contamination Of Salmonella Typhimurium And The Surrogate Enterococcus Faecium During Triple-Washing Of Butternut Squash, Jesica M. Temple

Graduate Theses, Dissertations, and Problem Reports (ETD)

Background: Recent foodborne illness outbreaks have been linked to fresh fruits and vegetables. For public safety, awareness of the risks of contamination from foodborne pathogens that can occur during post-harvest farming practices is essential to prevent foodborne outbreaks. Controlling the spread of foodborne pathogens on produce requires proper washing procedures, antimicrobials and doses. Given the speed and diversity of the produce being distributed, local incidents may become international emergencies. Methods: Studies were included if they assessed the efficacy of antimicrobials and various washing procedures and had to conclude the mitigation of cross-contamination of foodborne pathogens on produce grown in the …

Comparison Of Antimicrobials And Delivery Methods On The Inactivation Of Listeria Monocytogenes On Apples, Rebecca B. Stearns

Graduate Theses, Dissertations, and Problem Reports (ETD)

Introduction: Due to multi-state outbreaks of listeriosis on apples in 2015, 2017, and 2019, Listeria Monocytogenes (L. monocytogenes) has been deemed an emerging, under researched pathogen by the USDA-NIFA. Therefore, this study evaluated the efficacy of SaniDate 5.0®’s (SD) ability to inactivate L. Monocytogenes on apples when delivered through electrostatic sprayer (ES), garden sprayer (GS), and dip methods.

Methods: Organic apples were dip-inoculated with L. monocytogenes for 5 min and then dried for 10 min. Once dried, the inoculated apples were untreated (control), sprayed with water only, or treated with SD, 0.0064, 0.1, 0.25 and 0.50% for 20 …

Investigation Of A Novel Throughput Agent On Production Rate And Pellet Quality And The Development Of A Lab-Based Method To Predict Salmonella Reduction In Poultry Feed, Utilizing Varying Feed Manufacture Parameters, Timothy Paul Boltz

Graduate Theses, Dissertations, and Problem Reports (ETD)

Two experiments were conducted to evaluate a novel throughput agent and its mechanisms on production rate and pellet quality. An additional experiment using lab-based methods and models was conducted to predict Salmonella reduction in mash broiler feed. Feed mill pellet production rate is of great importance to integrated meat bird production. Feed hygienics are also of increasing concern for poultry producers.

In chapter 2, the effect of AZOMITE® (AZM) and varying inorganic phosphate sources (IPS) on pellet mill production rate and pellet quality was assessed. It is documented that the naturally abrasive properties of inorganic phosphate sources may scour the …

Evaluate The Efficacy Of A Mixture Of Peroxyacetic Acid And H2o2 Against The Survival And Cross-Contamination Of The Salmonella Surrogate Enterococcus Faecium On Tomatoes During Triple-Wash, Corey Waitman Coe

Graduate Theses, Dissertations, and Problem Reports (ETD)

Triple-wash with a mixture of peroxyacetic acid and H2O2 (SaniDate-5.0) during post-harvest processing of fresh produce has been recommended by West Virginia Small Farm Center to improve microbial safety. It has been well recognized that the washing of produce is more important for preventing cross-contamination than reducing foodborne pathogens. Furthermore, it may help improve public confidence in that the produce they obtain from locally grown farmers is safe for their consumption. determine the efficacy of SaniDate-5.0 for reducing the survival and preventing cross-contamination of the Salmonella surrogate Enterococcus faecium on tomatoes during triple-wash.

E. faecium ATCC-8459 (resistant to 100-ppm nalidixic-acid) …

Improving Microbial Safety Of Locally Grown Produce In West Virginia Area, Kawang Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

There is a growing concern regarding the microbial safety of farmers’ markets as fresh produce consumption in the United States is gaining popularity. The CDC reported 46% of foodborne illnesses are related to fresh produce. Consuming fresh produce raw removes a processing step, increasing the risk of cross-contamination, leading to illness. However, this risk can be mitigated by washing produce with antimicrobial solutions during post-harvest processes. To reduce the microbial load on fresh produce, the triple-wash process, where the produce is rinsed with water twice and lastly an antimicrobial solution (WWA). WWA is recommended by the WVU Extension Service Small …

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 (ETD)

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 …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

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 (ETD)

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 …

Protein And Lipid Characterization Of Acheta Domesticus, Bombyx Mori, And Locusta Migratoria Dry Flours, Emily N. Brogan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cricket (Acheta domesticus), silkworm pupae (Bombyx mori), and locust (Locusta migratoria) dry flours were obtained to examine the biochemical properties and composition of the flours. This study aimed to characterize the protein and lipid components of three insect species utilizing proximate composition analyses, amino acid composition analysis, protein solubility, SDS-PAGE, fatty acid composition analysis, and thin layer chromatography to determine lipid classes, and lipid extraction efficiency. Kjeldahl determined the cricket, locust, and silkworm flours contained 72.0%, 53.1%, and 71.2% protein, respectively. All proximate composition analyses were significantly (p< 0.05) different between species. Amino acid composition analysis revealed that the flours contained 3.6-3.9% and 0.90-1.5% of lysine and methionine, respectively. Many countries have cereal grains and legumes as a staple in their diet that contain these limiting amino acids. Essential amino acids were 22% of total amino acids. Protein solubility revealed that the three species studied were most soluble in alkaline environments with highest protein solubility occurring at pH 13 at 66% solubility in silkworm. Lowest solubility occurred in more acidic conditions between pH 4-5. SDS-PAGE revealed five major protein fractions with estimated molecular weights of 27 (cuticle proteins), 41 (arginine kinase), which has been identified as an allergen in shrimp, 42 (actin), 71 (hemocyanin), and 220 myosin) kDa. Soxhlet extraction determined cricket, silkworm, and locust flours contained 15.4%, 33.3%, and 11.4% lipid, respectively. The only omega-3 fatty acid found in the flours was α-linolenic acid. Silkworm flour contained the most α-linolenic acid at 33.3% of total fatty acids, followed by locust (13.7%), and cricket (0.6%). TLC resolved lipids for typical lipid classes. The four major lipid classes noted were triacylglycerol, free fatty acid, cholesterol, and phospholipid. Lipid extraction efficiency found that the organic solvents chloroform and methanol had the highest lipid extraction yield in both cricket (69.3%) and locust (93.0%). Methyl-tertiary-butyl ether (MTBE) extracted lipids most efficiently in the silkworm. Proteins and lipids found in insects need to be isolated to further or commercial use.