Life Sciences Commons^™

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 …

Complex Glycan Utilization Preferences Of Human Gut Bacteria, Yunus Emre Tuncil

Open Access Dissertations

Complex glycans, making up dietary fiber, have gained significance in recent years as they are the main energy source for the colonic microbiota which are physiologically important for the host health. Understanding glycan utilization strategies of the members of this community is essential to maximize beneficial health outcomes obtained from them. In order to investigate how the members of our gut microbiota utilize glycans and activate their respective polysaccharide utilization loci (PULs), we performed a series of time-course assays in which two model organisms, Bacteroides thetaiotamicron (Bt) and B. ovatus (Bo), were individually grown in a medium containing carbohydrates utilized …

Prevalence And Antimicrobial Resistance Patterns Of Salmonella Isolated From Poultry Farms, Carmen G. Velasquez Moreno

Open Access Theses

Antimicrobial agents are used in human medicine to treat infections by inhibiting the growth of bacteria. The same or similar drugs are used in in food-producing animals for therapeutic and sub-therapeutic purposes. Antimicrobial resistant bacteria that develop on farms are a public health risk as these organisms may contribute to treatment failures in infected humans. The main objective of this study was to determine the prevalence of Salmonella isolated from poultry farms in two different seasons to evaluate the effect of recommended biosecurity practices. Specifically, we identified Salmonella serotypes, measured antimicrobial resistance (AMR), and characterized AMR patterns. We hypothesized that …

A Comparison Of The Efficacy Of Radiant And Immersion Frying Using Hash Brown Patties As A Model Food Matrix, Kaitlin R. Kaczay

Open Access Theses

Radiant frying is an alternative technique to traditional immersion frying. While enjoyed by consumers, immersion fried foods are typically high in fat. Radiant frying uses infrared energy to produce finished products with similar sensory characteristics to traditional frying, but with significantly less fat. This research compared the efficacy of radiant and immersion frying using hash brown patties as a model food matrix by measuring temperature profiles, heat flux profiles, moisture and oil contents, peak shear force, color, mottling, and crust thickness as well as executing semi-trained and untrained sensory evaluations. The FryLess 100K Radiant Fryer was used for all experimentation. …

Evaluation Of Thermal Process Lethality In Meat For Non-Pathogenic Escherichia Coli As A Surrogate For Salmonella, Morgan Alyse Redemann

Open Access Theses

Non-typhoidal Salmonella is the leading cause of foodborne illness in the United States, resulting in about 20,000 hospitalizations and nearly 380 deaths annually. The meat processing industry has been especially plagued by Salmonella, from meat-inherent sources and more alarmingly, cross-contamination. For ready-to-eat (RTE) meat products specifically, this can cause significant problems in processing facilities ensuring safe product for consumption, resulting in foodborne illness.

The development of standard lethality compliance guidelines by the United States Department of Agriculture Food Safety and Inspection Service (USDA-FSIS) within Appendix A assists processors in confirming that Salmonella is inactivated in RTE beef and poultry products, …

Genomic And Transcriptomic Analysis Of Biofilm Formation In Persistent And Transient L. Monocytogenes, Clara Assisi

Open Access Theses

The Next Generation Sequencing (NGS) has been popularized and aid in the advancement of many fields of science. The other field of science that is being revolutionized is food science and technology, especially food safety. NGS application in food safety, especially the whole genome sequencing analysis (WGS), has been widely used for tracing back the source of outbreaks. The other application of NGS that is also being developed is the analysis of global transcriptomic or RNA-sequencing (RNA-Seq). In this research, we utilize NGS (Ilumina MiSeq Sequencing platform) to perform sequence comparison and identify single nucleotide polymorphisms (SNPs) and observe the …

Antibacterial Activity Of Essential Oil Encapsulated Sodium Iota-Carrageenan Fibers, Carlos D. Carter

Open Access Theses

Spoilage microorganisms cause food waste and loss of quality. While the foodborne pathogen outbreaks lead to thousands of hospitalizations and deaths. Essential oils (EOs), plant extracts, possess the required antimicrobial activities and thus their usage stands out as a feasible approach for controlling the undesirable bacterial growth in food systems. However, EOs are highly volatile and lose their activity upon exposure to environmental conditions. In this regard, their encapsulation in Generally Recognized As Safe (GRAS) matrices such as food grade polysaccharides especially iota-carrageenan could be one of the viable alternatives. Iota-carrageenan, sulfated polysaccharide from marine algae, is being used in …

Impact Of Microwave-Assisted Heating And Enzymatic Treatment On Functional And Antioxidant Properties Of Rainbow Trout (Oncorhynchus Mykiss) By-Product Hydrolysates, Elizabeth Bich Hang Nguyen

Open Access Theses

Fish protein hydrolysates (FPH) have been widely used as a mean to better utilize fishery by-products through the use of proteolytic enzymes to produce a wide range of functional peptides that can be used as food ingredients. Studies have shown that these functional peptides have enhanced interface-stabilizing properties (e.g. functionality) and antioxidant activity. FPH production can be accelerated by using rapid heating methods (e.g. microwave) compared to slower conventional heating (CH). The objective of this study was to investigate the effects of microwave heating (MW) during enzymatic hydrolysis on functionality and antioxidant properties of FPH. Treatments consisted of adding Alcalase™ …

Influence Of Dietary Polyphenols On Carbohydrate Intestinal Digestion And Absorption, Sydney E. Moser

Open Access Dissertations

Both epidemiological and clinical evidence support the notion that polyphenol rich foods and beverages may modify glycemic response, glucose homeostasis and subsequent risk of Type-2 diabetes. In vitro evidence typically derived from experiments with pure phenolics and phenolic rich extracts have pointed to this benefit being associated with two potential mechanisms: (1) the ability of specific polyphenolics to inhibit carbohydrate digestion (amylase and glucosidase) and (2) polyphenolic inhibition of intestinal glucose transport. While the high potential of these activities is evident, little is actually known regarding the extent to which these benefits are extendable to the actual food matrix these …

Quality And Safety Attributes Of Sun-Dried Raisins From Afghanistan, Stacy A. Mccoy

Open Access Theses

Raisins are an important export commodity for Afghanistan, however, Afghan packers are challenged to export to markets seeking high quality products due to limited knowledge regarding their quality and safety. To evaluate this, Afghan raisin samples from pre-, semi-, and post-processed raisins were obtained from a raisin packer in Kabul, Afghanistan. The raisins were analyzed and compared to U.S. standards for processed raisins. The samples tested did not meet U.S. import standards for embedded sand, but the process used to clean the raisins is suitable to maintain food safety standards.

Previous Afghan raisin shipments have been rejected from the U.S. …

Invasive Silver Carp (Hypophthalmichthys Moltrix) Protein Hydrolysates And Their Efficacy In Increasing Seedling Vigor And Reducing Seed Borne Pathogen Growth, Shanleigh Pauline Thomson

Open Access Theses

Silver carp are an invasive fish species introduced into the United States within the last forty years. Unable to be effectively eradicated or commercialized as a source of food, other methods must be developed to control and/or use these fish. Fish protein hydrolysates (FPH) are products derived from the proteins inherent within fish. Development of FPH from Silver carp for a variety of uses could aid in controlling their expanding population and provide organic produces with a seed treatment option which is not available to them currently.

In the first study, FPH were used as a seed vigor treatment for …

Evolution Of Food Quality Demand In The Food Service Industry In China: The Case Of Duck, Rachel Alison Carnegie

Open Access Theses

Booming economic growth and rising consumer incomes have impacted food preferences and purchasing behavior in China. At the same time, several internationally publicized food safety incidents, particularly in the animal husbandry sector, have heightened awareness of and concern for food safety and quality in meat and dairy. Rising quality demand and safety concerns have been studied at length in the food retail sector, but also appear to be important in the food service industry. This research uses data from a survey of duck restaurant managers and consumers in Beijing, Shanghai, Chengdu, and Guangzhou to determine preferences and willingness to pay …

High Voltage Atmospheric Cold Plasma Treatment Of Refrigerated Chicken Eggs For Control Of Salmonella Enteritidis On External Surfaces, Yi Chen

Open Access Theses

The global market for eggs is projected to reach 1.154 trillion by the year 2015. The number one risk to consumers from chicken eggs is contamination with Salmonella Enteritidis (SE). FDA estimates each year 142,000 illnesses in the U.S. are caused by SE contamination in chicken eggs. The first objective of this research study was to evaluate a novel High Voltage Atmospheric Cold Plasma (HVACP) technology in reducing externally inoculated SE on refrigerated chicken eggs. Raw, chicken eggs attached with SE population (10 7 CFU/ml), were placed in plastic containers filled with either dry Air (22%O2 , 78%N2 ) or …

Quality Changes In Hermetically Stored Corn Caused By Fungi And Sitophilus Zeamais, Nda-Agyima Addae-Mensah K

Open Access Theses

Hermetic storage has been shown to be effective in controlling insect pests and maintaining grain quality of dry grains at 13% moisture and below. However, the feasibility and use of hermetic storage for grains at intermediate mid-moisture levels under the influence of the sub-Saharan African weather conditions is relatively unknown. Hermetic storage experiments were conducted on grade 1 "6297 and 6333 VT RIB" hybrid corn under controlled temperature conditions at 10 degrees centigrade and 25 degrees centigrade at target approximate moisture content levels of 11, 15, 18 and 21% wet basis for a total storage period of 6 months. Corn …

Shrinkage Prediction During Pasta Dehydration, Gina Michelle Bressani

Open Access Theses

Shrinkage models from different fields of study were reviewed. Pasta was used as a model to further develop the hypothesis of predicting shrinkage in terms of the rate of relaxation and the rate of moisture loss. An extended literature review of pasta properties, such as isotherms, diffusivity, glass transition, rheological properties, and shrinkage was conducted. Isotherm and glass transition models were developed from the literature data acquired. Creep was tested with a 25 mm-diameter flat plate at 20 to 40°C at varying moisture content. Viscoelastic properties for the Burgers model for creep were determined, where higher moisture content samples resulted …

Fatty Acids And Mercury In Seventy Seven Species Of Commercially Available Finfish In The United States, Dennis P. Cladis

Open Access Theses

Finfish are consumed across the United States and constitute an important part of the American diet. However, seafood consumption can be a tenuous topic, with supporters highlighting the health benefits of eicosapentaenoic acid (EPA, C20:5n3) and docosahexaenoic acid (DHA, C22:6n3) and opponents emphasizing the neurotoxicity of methylmercury. Because all fish contain varying amounts of EPA, DHA, and methylmercury, the need for clear and unbiased information is essential to alleviate the confusion experienced by many consumers and empower them to make informed decisions regarding seafood consumption. As the market changes and more fish originate from aquaculture sources, where diets are controlled, …

Developing Strategies To Mitigate And Control Environmental Listeria Monocytogenes In Retail Delis, Susan Rose Hammons

Open Access Theses

There are many research avenues being investigated at institutions nationwide with the intent to reduce the public health risk of listeriosis. Approaches include studies on L. monocytogenes transmission dynamics in retail delis, observations of deli worker practices, a structured expert elicitation on transmission dynamics and statistical modeling of listeriosis risk impact factors. This thesis describes my contribution to the work being done in our group to (i) understand prevalence and persistence of L. monocytogenes and Listeria species non-monocytogenes on environmental surfaces (food contact and non-food contact); (ii) identify characteristics or practices which place stores at increased risk for L. …

Anticipatory And Reactive Responses To Chocolate Restriction In Frequent Chocolate Consumers, Chelsey L. Keeler

Open Access Theses

Many individuals have difficulty adhering to a weight loss diet. One possible explanation could be that dietary restriction paradoxically contributes to overconsumption. The objective of this study was to examine ingestive behavior under a forced chocolate restriction, with a focus on the anticipatory restriction period and the post-restriction period in frequent chocolate consumers. Fifty-six male (N=18) and female (N=38) high chocolate consumers with high or low cognitive disinhibition aged 27.70 ± 11.09 years with a mean BMI of 25.68± 5.92 kg/m2 participated. Chocolate snacks were provided for the first, second, and sixth week of the study to establish baseline, pre-restriction …

Study Of The Sustainbility Issues Of Food Production Using Vertical Farm Methods In An Urban Environment Within The State Of Indiana, Victor Mendez Perez

Open Access Theses

There are several problems around the globe related to water scarcity, energy shortages, deforestation and loss of fertile land, and food security. Climate change is making environmental and social issues arise. Issues such as, changes in the agricultural landscape, increasing population (9 billion is the expected population for 2040), rising food borne illnesses, scarcity of drinking water, and more crop failure due to plant pathogens and insect pests, among other factors make this study specially significant. Vertical farming could be a potencial solution to some of these problems.

Due to these problems the present thesis analyzed vertical farming as a …

Efficacy Of Manual Dishwashing And Sanitizer Wiping In Removing Food Soils From Chel Knives, Xiaodi Sun

Open Access Theses

Improperly cleaned and sanitized chef knives may present a potential contamination risk and thus be a risk for foodborne illness. Therefore, ensuring effective cleaning and sanitization of knife surfaces may help prevent the spread of foodborne pathogens. The primary objective of this research was to compare the efficacies of two different cleaning methods (three-compartment manual dishwashing and sanitizer wiping) at removing food soils from contaminated chef knives using procedures that are typical of restaurant kitchens. Knife wiping and washing procedures were determined and standardized according to an observation of knife cleaning behavior in a kitchen. Adenosine triphosphate (ATP) bioluminescence was …

Effects Of Wheat Grain Moisture: Quality, Germination, And Relationship To Accumulated Growing Degree Days, Kirsten Thomas

Open Access Theses

Bread wheat (Triticum aestivum L.) is a cereal crop of global importance. As global demand increases, it is essential to increase the quality and efficiency of crop production. Harvesting wheat early provides an opportunity for increased grain quality, and it may also allow the grower to double-crop soybean ( Glycine max L.) after wheat more effectively. Our objectives were to determine if harvesting grain early, at high moisture would, 1) increase milling and baking quality and 2) improve germination potential. As a result of these objectives, we will develop a model to predict dry-down of wheat. Five soft red …

Effect Of Carvacrol-Loaded Nanoemulsions On A Bioluminescent Strain Of Escherichia Coli O157:H7, Clara Maria Vasquez Mejia

Open Access Theses

Nanoemulsions have been shown to be effective delivery vehicles for poorly water soluble natural antimicrobials. In this study the antimicrobial activity of carvacrol (5-isopropyl-2-methylphenol) nanoemulsions against a bioluminescent Escherichia coli O157:H7 was investigated using light emission as an indicator of cell viability. Different emulsifiers (Ultralec Lecithin and Tween 20), oils (Palm stearin and Coconut oil) and various carvacrol concentrations (0, 1, 2 and 2.5%) were evaluated. Bioluminescence was monitored in situ using a Hamamatsu (photo multiplier tube) sensor module integrated with a Programmable Logic Controller interfaced with a PC for data acquisition. Bioluminescence decreased rapidly with the addition of emulsions …

Brain Bioavailability Of Polyphenols: Implications For Delivery Of Brain Health Benefits, Tzu-Ying Chen

Open Access Dissertations

Consumption of fruits and vegetables has been associated with neuroprotection and cognitive benefits throughout the life span. These associations have sparked interest in plant-derived polyphenols as biologically active agents with potential for targeting brain benefits. However, little is known regarding the ability of the polyphenols or their metabolites from polyphenol-rich products to cross the blood-brain-barrier, and be available for biological action. Furthermore, additional insight is needed on factors affecting the absorption and brain distribution of polyphenol metabolites in vivo. To fill gap in current knowledge, this thesis will focus on the effects of diabetogenic diet and diabetic state which have …

Invasive Silver Carp (Hypophthalmichthys Molitrix) Protein Hydrolysates- A Potential Source Of Natural Antioxidant, Sravanthi Priya Malaypally

Open Access Dissertations

Invasive silver carp (Hypophthalmichthys molitrix), continue to spread over the Mississippi River causing a great concern for the river ecosystem due to their impact on native fish species. To minimize the negative effects of silver carp, many strategies were implemented including using it for animal feed, as fertilizers or simply discarding them into waste. However, these fish are high in protein content, making them excellent starting material for protein-derived by-products. One alternative is to recover and modify the protein in the fish into bioactive food ingredient. In the functional/ nutraceutical food industry, there is high demand for antioxidant agents. In …