Food Microbiology Commons^™

Modeling The Survival Of Salmonella In Soy Sauce-Based Products Stored At Two Different Temperatures, Ana Cristina Arciniega Castillo

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

Acidified foods are defined in the regulations as “low acid foods to which acid(s) has been added to bring finished pH to 4.6 or below”. As the market for these products expands, an increasing number of them are being processed with reduced heat treatment, relying on acid alone to ensure the destruction of pathogens. When considering the survival rate of microbial pathogens in these products, pH, water activity, temperature, salt content and holding time are integral and must be considered together.

Despite improvements in production, handling, and distribution of food products in recent years, protecting consumers from foodborne illness still …

Validation Of Extrusion Processing For The Safety Of Low-Moisture Foods, Tushar Verma

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

Salmonella in low-moisture foods is an emerging challenge due to numerous food product recalls and foodborne illness outbreaks. The new Food Safety Modernization Act requires the food processors to validate their process controls that indeed kills the desired number of bacteria. This research had two major objectives: 1) Develop a response surface model for Salmonella inactivation during the extrusion of low-moisture food 2) Evaluate the use of Enterococcus faecium NRRL B-2354 as an adequate surrogate for Salmonella during the extrusion of low-moisture food. Oat flour was selected as a low-moisture food model. For inoculation, cocktail of five different strains of …

Persistence Of Enteric Viruses On Surfaces Under Varying Environmental Conditions, Nicole L. Turnage

Graduate Theses and Dissertations

Human enteric viruses such as human norovirus (hNoV) and Aichivirus A (AiV) are common foodborne viruses with hNoVs being identified as the leading causative agent of foodborne illnesses in the U.S. Moreover, hNoVs have been identified as the leading cause of nonbacterial acute gastroenteritis in the U.S. and worldwide. Fomite surface contamination is a major transmission route for enteric viruses. The application of an optimized virus recovery method from fomites is essential for better understanding of virus persistence under varying environmental conditions (EC). This study aimed to optimize a surface sampling method for virus recovery from nonporous food contact surfaces …

Phylogenetic Diversity Of The Bacterial Communities In Craft Beer, Lindsey Rodhouse

Graduate Theses and Dissertations

The craft beer industry is increasing in popularity in the United States. The craft brewing process typically does not use a pasteurization step, therefore the boiling process is the primary critical control step. Any microorganisms introduced after boiling, or those that are not killed during boiling, are likely to participate in fermentation and persist in the final product. Previous culture-based studies have isolated bacteria and yeast from craft beers at specific time points, but little research has been done on the process as a whole. The objectives of this research are to (1) track bacteria development throughout the brewing process …

The Recovery Of Protein From Egg Yolk Protein Extraction Granule Byproduct, Irene Jennifer Kaufman

Master's Theses

In addition to proving an excellent source of nutrients, eggs are used in the food, cosmetic, and biotechnology industries for their rheological and bioactive properties. Much of the potential for the added value is in individual components of the egg, rather than the whole egg. At low speed centrifugation, yolk separates into two distinct fractions—granules and plasma. It is becoming increasingly popular in the industry to remove the plasma fraction of the egg yolk to use for its livetins, particularly immunoglobulin Y, leaving behind a granule by-product (“yellow cake”). Previous research has shown potential added-value from the granule fraction, especially …

Knowledge Of Food Safety And Food Handling Practices Amongst Food Handlers In The Republic Of Ireland, Nora A. Moreb, Anushree Priyadarshini, Amit Jaiswal

Articles

Food safety concerns have existed for a long time, as millions of people across the globe suffer from food borne disease every year. Contamination of food owing to limited knowledge of food safety practices primarily increases the risk of food borne illnesses. In the present study, quantitative research was carried out to gauge the level of food safety knowledge amongst people living in Ireland. A total of 1069 participants from all over the Republic of Ireland contributed to the survey (of which 821 were included in this research). Results showed that the residents of Ireland overall had an average levelonknowledge …

Effect Of Red Cabbage Extract On Minced Nile Perch Fish Patties Vacuum Packaged In High And Low Oxygen Barrier Films, Ayse Demirbas, Yavuz Yagiz, Ziynet Boz, Bruce A. Welt, Eric Mclamore, Maurice Marshall, William Pelletier, Amarat Simonne

Journal of Applied Packaging Research

Oxidation of polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fish causes loss of product quality. Oxidative rancidity causes loss of nutritional value and undesirable color changes. Therefore, powerful antioxidant extracts may provide a relatively low cost and natural means to reduce oxidation, resulting in longer, higher quality and higher value shelf life of foods.

In this study, we measured synergistic effects of red cabbage antioxidant and vacuum packaging on lipid oxidation in fresh tilapia patties using thiobarbituric acid reactive substances (TBARS) assay, peroxide value (PV), pH and color analysis.

Concentrated red cabbage extract was obtained …

Dna Barcoding Analysis Of Seafood Accuracy In Washington, D.C. Restaurants, David Stern, Eduardo Castro Nallar, Jason Rathod, Keith A. Crandall

Computational Biology Institute

In Washington D.C., recent legislation authorizes citizens to test if products are properly represented and, if they are not, to bring a lawsuit for the benefit of the general public. Recent studies revealing the widespread phenomenon of seafood substitution across the United States make it a fertile area for consumer protection testing. DNA barcoding provides an accurate and cost-effective way to perform these tests, especially when tissue alone is available making species identification based on morphology impossible. In this study, we sequenced the 5′ barcoding region of the Cytochrome Oxidase I gene for 12 samples of vertebrate and invertebrate food …

Seaweed Carotenoid Fucoxanthin As Functional Food., Nissreen Abu-Ghannam, Emer Shannon

Books/Book Chapters/ Proceedings

Fucoxanthin is a bioactive compound found in one of the most prolific and sustainable organisms on the planet, alga. Its efficacy and potential in terms of health applications have been widely reported in clinical studies. Technical modifications, such as encapsulation, and sensory trials must be undertaken before fucoxanthin can be successfully utilised as a functional food ingredient. Factors to consider include solubility in the food matrix, organoleptic effects, stability, preservation against oxidation, consumer acceptability, bioavailability, and toxicity risk. Possible solutions may include the development of more efficient and greener extraction technologies, which require shorter extraction times and less solvent, and …

Achieving Reactive Species Specificity Within Plasma Activated Water Through Selective Generation Using Air Spark And Glow Discharges, Peng Lu, Daniela Boehm, Paula Bourke, Patrick J. Cullen

Articles

Plasma activated liquids (PAL) attract increasing interest with demonstrated biological effects. Plasma exposure in air produces stable aqueous reactive species which can serve as chemical diagnostics of PAL systems. Here, we tailor aqueous reactive species inside plasma activated water (PAW) through treating water with AC air spark and glow discharges in contact with water. Chemical probing demonstrated species specificity between two types of PAW. Spark discharge PAW contains 2 2 H O and 3 NO , while 2 NO and 3 NO are generated in glow discharge PAW. Species formation in different PAWs have been discussed in terms of discharge …

Growing Yeast For Livestock, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Over 500,000 tons of organic materials such as food scraps are disposed of each year in Wisconsin. A large percentage of this material could be composted or turned into useful products. The purpose of this article is to educate farmers and organizations on how to turn food waste into a high value food source for livestock. Yeast can be grown at any time of the year without the large inputs of agricultural chemicals and machinery that is common with other feed production methods. A yeast growing facility can be scalable to any size the producer wants such as a small …

The Use Of Lactobacillus Salivarius L28 As A Bioprotective Culture In Dry Fermented Sausages, Kathy Flynt Collins

Theses and Dissertations--Animal and Food Sciences

A challenge study to validate a 5 log₁₀ CFU/g reduction of non-O157 Shiga-toxin producing Escherichia coli (STEC) in dry fermented sausage (DFS) was performed. A 4.49 ± 0.474 log₁₀ CFU/g was achieved over two trials. The results indicated that the process was not effective in reducing the pathogen to the level required of most pathogens by the USDA.

Lactobacillus salivarius L28 (L28) was screened in vitro for the ability to inhibit STEC utilizing the paper disk diffusion method. This strain is a known bacteriocin producer. The results revealed that L28 would be a good candidate for use as …

The Survival Of Various Pathogenic Organisms In Fats And Oils, Kelsey Ellen Lamb

Theses and Dissertations--Animal and Food Sciences

The research within this thesis sought to determine the ability of various animal derived fats and plant derived oils to support the survival of several pathogenic cocktails over a multitude of storage times. The Salmonella study explored the survival rate of a four strain Salmonella cocktail in beef tallow, pig lard, duck fat, coconut oil, and extra virgin olive oil over seven days at 26˚C and 37˚C storage. The animal fats and the coconut oil supported the survival of the bacteria until the conclusion of the study. The Shiga-toxin producing Escherichia coli study explored the survival rate of a five …

A Critical Assessment Of The “Sterile Womb” And “In Utero Colonization” Hypotheses: Implications For Research On The Pioneer Infant Microbiome, Maria Elisa Perez-Muñoz, Marie-Claire Arrieta, Amanda E. Ramer-Tait, Jens Walter

Department of Food Science and Technology: Faculty Publications

After more than a century of active research, the notion that the human fetal environment is sterile and that the neonate’s microbiome is acquired during and after birth was an accepted dogma. However, recent studies using molecular techniques suggest bacterial communities in the placenta, amniotic fluid, and meconium from healthy pregnancies. These findings have led many scientists to challenge the “sterile womb paradigm” and propose that microbiome acquisition instead begins in utero, an idea that would fundamentally change our understanding of gut microbiota acquisition and its role in human development. In this review, we provide a critical assessment of the …

Controlling Brochothrix Thermosphacta As A Spoilage Risk Using In Package Atmospheric Cold Plasma, Apurva Patange, Daniela Boehm, Carmen Bueno-Ferrer, Patrick J. Cullen, Paula Bourke

Articles

Brochothrix thermosphacta is a predominant spoilage microorganism in meat and its control in processing environments is important to maintain meat product quality. Atmospheric cold plasma is of interest for control of pathogenic and spoilage microorganisms in foods. This study ascertained the potential of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) for control of B. thermosphacta in response to key parameters such as treatment time, voltage level, interactions with media composition and post treatment storage conditions. Challenge populations were evaluated as suspensions in PBS, as biofilms in meat model medium and surface attached on raw lamb chops under MAP.

ACP treatment …

Comparative Genomic Analysis Of Two Serotype 1/2b Listeria Monocytogenes Isolates From Analogous Environmental Niches Demonstrates The Influence Of Hypervariable Hotspots In Defining Pathogenesis, Aidan Casey, Kieran Jordan, Aidan Coffey, Edward M. Fox, Olivia Mcauliffe

Department of Biological Sciences Publications

The vast majority of clinical human listeriosis cases are caused by serotype 1/2a, 1/2b, 1/2c, and 4b isolates of Listeria monocytogenes. The ability of L. monocytogenes to establish a systemic listeriosis infection within a host organism relies on a combination of genes that are involved in cell recognition, internalization, evasion of host defenses, and in vitro survival and growth. Recently, whole genome sequencing and comparative genomic analysis have proven to be powerful tools for the identification of these virulence-associated genes in L. monocytogenes. In this study, two serotype 1/2b strains of L. monocytogenes with analogous isolation sources, but …

Association Mapping Of Seed Weight, Protein, And Sucrose Content; And Kinetics Of Edamame Under Infrared Treatment, Laura Melissa Lara Santisteban

Graduate Theses and Dissertations

Edamame is a specialty large-seeded soybean (Glycine max L. Merr.) harvested at an immature stage (R6) that has become the second largest consumed soyfood. Although United States is the largest soybean producer, majority of edamame is imported from Asia, highlighting the importance of developing new edamame varieties. Association mapping (AM) provides an alternative to bi-parental linkage mapping method to detect quantitative trait loci (QTL) adding higher resolution and broader germplasm information. Seed weight, sucrose, and protein are quantitative traits of value when selecting edamame lines. However molecular mechanisms controlling each of these traits are still inconclusive and have not been …

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 …

Effects Of Fermentation By Yeast And Amylolytic Lactic Acid Bacteria On Grain Sorghum Protein Content And Digestibility, Christina Day

Graduate Theses and Dissertations

Grain sorghum is an underutilized crop despite many advantages to its cultivation. A drought-tolerant plant with many pest-resistant cultivars, its applications are limited by problems with nutrient availability, particularly protein digestibility. Digestibility of grain sorghum protein is reduced by antinutritional compounds in the grain like tannins and phytates, and by moist-heat cooking. Some of these concerns can be mitigated by how the grain is processed. Fermentation is one processing method that can improve digestibility. Fermentation can also concentrate protein in a substrate. In this experiment, grain sorghum was subjected to different treatments and used as a substrate for yeast fermentation. …

A Bifunctional Nanocomposites Based Electrochemical Biosensor For In-Field Detection Of Pathogenic Bacteria In Food, Meng Xu

Graduate Theses and Dissertations

This research focused on the application of electrochemical biosensors for the rapid detection of pathogenic bacteria, Escherichia coli O157:H7 and Salmonella Typhimurium, in foods. The possible presence of pathogenic bacteria in foods has always been a great threat to the wellbeing of people and the revenue of food companies. Therefore, the demand for rapid and sensitive methods to detect foodborne pathogens is growing. In this research, an impedimetric immunosensor was first developed for the rapid detection of E. coli O157:H7 and S. Typhimurium in foods. It was based on the techniques of immunomagnetic separation, enzyme labelling, and electrochemical impedance spectroscopy …

Risk Assessment And Research Synthesis Methodologies In Food Safety: Two Effective Tools To Provide Scientific Evidence Into The Decision Making Process, Juan E. Ortuzar

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

The food supply chain is a complex and diverse system. Some food products need minimum processing to reach the consumers, while others involve several different processes, countries and suppliers, can take several months to be on the table of the end consumer. Regarding food safety, the public health of consumers is at stake and the consequences of outbreaks could prove disastrous. This has been recognized as a matter of global importance for the food industry and authorities around the world since several efforts to improve quality, safety and trade of food have arisen since the early 1960s. The birth of …

Antimicrobial Inhibitory Activities Of Phenolic Extracts From Four Selected Soybean Hulls In Culture And Chicken Skin Model Systems, And Preliminary Ace-Inhibitory Activity, Rajaa Abdulkair Abutheraa

Graduate Theses and Dissertations

Soybean components provide health benefits to humans. Soybean hulls, a major by-product of the soybean processing industry consist of complex carbohydrates, proteins, lipids and polyphenols such as anthocyanidins, proanthocyanidins and isoflavones. The polyphenolic compounds in the hulls give them various colors such as black, brown, green, yellow or even a mottled appearance. Studies have reported different soybean varieties with varying total phenolic compounds in their seed hulls, which have antioxidant property. Phenolic extracts can be used as substitutes for synthetic antimicrobials and preservatives to assist in preventing the growth of pathogens such as Salmonella Typhimurium, E coli 0157:H7, and Campylobacter …

A Portable And Automatic Biosensing Instrument For Detection Of Foodborne Pathogenic Bacteria In Food Samples, Zhuo Zhao

Graduate Theses and Dissertations

Foodborne diseases are a growing public health problem. In recent years, many rapid detection methods have been reported, but most of them are still in lab research and not practical for use in the field. In this study, a portable and automatic biosensing instrument was designed and constructed for separation and detection of target pathogens in food samples using nanobead-based magnetic separation and quantum dots (QDs)-labeled fluorescence measurement. The instrument consisted of a laptop with LabVIEW software, a data acquisition card (DAQ), a fluorescent detector, micro-pumps, stepper motors, and 3D printed tube holders. First, a sample in a syringe was …

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 …

Stable Engraftment Of Bifidobacterium Longum Ah1206 In The Human Gut Depends On Individualized Features Of The Resident Microbiome, María X. Maldonado-Gómez, Inés Martínez, Francesca Bottacini, Amy O’Callaghan, Marco Ventura, Douwe Van Sinderen, Benjamin Hillmann, Pajau Vangay, Dan Knights, Robert W. Hutkins, Jens Walter

Department of Food Science and Technology: Faculty Publications

Live bacteria (such as probiotics) have long been used to modulate gut microbiota and human physiology, but their colonization is mostly transient. Conceptual understanding of the ecological principles as they apply to exogenously introduced microbes in gut ecosystems is lacking. We find that, when orally administered to humans, Bifidobacterium longum AH1206 stably persists in the gut of 30% of individuals for at least 6 months without causing gastrointestinal symptoms or impacting the composition of the resident gut microbiota. AH1206 engraftment was associated with low abundance of resident B. longum and underrepresentation of specific carbohydrate utilization genes in the pre-treatment microbiome. …

Fungi In The Healthy Human Gastrointestinal Tract, Heather E. Hallen-Adams, Mallory J. Suhr

Department of Food Science and Technology: Faculty Publications

Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are …

Mitigating Prevalence And Persistence Of L. Monocytogenes Using Novel Sanitation Strategies In Delis, Susan Rose Hammons

Open Access Dissertations

Ready-to-eat (RTE) deli meats sliced at retail are predicted to cause 83% of deli meat-associated listeriosis cases annually. While L. monocytogenes is commonly found in delis (55-90%), environmental prevalence varies by store (0-40%). Study 1 evaluated efficacy of 10 standardized SSOPs by testing 28 food and non-food contact surfaces for L. monocytogenes over 6 months in 30 retail delis. Intervention strategies employed in this study significantly decreased L. monocytogenesprevalence on FCS and NFCS in stores with moderate prevalence (0.5%, 0.8% reduction). However, we found that L. monocytogenes could persist despite implementation of SSOP control strategies. Study 2 assessed an …

Microbes In Rough Rice – Prevalence, Growth Kinetics And Links To Dry Matter Loss, Supriya Thote

Graduate Theses and Dissertations

The prevalence of microorganisms on freshly-harvested long-grain hybrid, long-grain pureline, and medium-grain rice has not been elucidated. The first objective of this two-part study was to determine the relative prevalence of microbes on freshly-harvested, high moisture content rice of different types and cultivars. The total and surface aerobic plate counts (APC) and mold counts were determined in terms of log10 colony forming units per gram of rice (log10 CFU/g) for six rice cultivars over two years. In 2013, among harvested samples of all the studied rice cultivars, the long-grain hybrid cultivars had the lowest APC levels (M = 8.10, SD …

Listeria Monocytogenes Strain Variation: Starvation, Metabolism, And Macrophage Survival, Nathan A. Jarvis

Graduate Theses and Dissertations

Listeria spp. are often isolated from raw and processed food products. Listeria monocytogenes is responsible for death rates of 10 to 30% in immune compromised people; it can also infect a vast range of animals. There are numerous reports of poultry harboring or becoming infected with L. monocytogenes. First, this research assessed the ability of L. monocytogenes to replicate within chicken macrophages. Using the gentamicin-killing assay, a cell culture of chicken macrophage-like cells (HD11) were infected with two strains of L. monocytogenes individually (EGD-e and Scott A). Results show that unlike data on mouse macrophages, intracellular L. monocytogenes do not …

In Vitro Fermentation Patterns Of Rice Bran Components By Human Gut Microbiota, Tung Minh Pham

Graduate Theses and Dissertations

The prevalence of colorectal cancer (CRC) has been increasing in recent years worldwide. In the United States, it is ranked the second leading cause of cancer death. Risks of CRC increase with age and are associated with several lifestyle factors such as diet, drinking and smoking habits, and levels of physical activity. There is an abundance of scientific literature demonstrating the protective roles of several dietary components including fibers and polyphenolic compounds. These compounds have been shown to be able to positively modulate gastrointestinal ecology by increasing the production of short-chain fatty acids (SCFA) and promoting the population of beneficial …