Life Sciences Commons^™

Development Of An Intact Mass Spectrometry Method For The Detection And Differentiation Of Major Bovine Milk Proteins, Emily F. Harley-Dowell

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

The authentication of products with claims regarding protein sources or compositions is a challenge for traditional analytical methods, which generally lack the required specificity whole protein analysis can provide. For example, the establishment of milk as “A2” is achieved through genetic testing of cows before milk production, with no methods to authenticate milk products themselves. Establishment of A2 milk is completed through genetic testing of the cows before milk production, but with no methods to authenticate the milk products themselves. Intact protein mass spectrometry (MS) has the potential to directly authenticate protein products, including specific proteoform claims. The development of …

Influence Of Overcooking On Food Digestibility And In Vitro Fermentation, Wensheng Ding

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

Areas of char or overcooking commonly appear in foods people consume. It has been reported that overcooked food is harmful to human health. However, little research exists on the effect of overcooking on in vitro protein and starch digestibility and gut microbial fermentation. This study aimed to reveal the connection between overcooking and in vitro protein and starch digestibility and gut microbial fermentation. In vitro protein digestibility of an overcooked ground beef patty was almost half that of a standard cooked sample (27 ± 2% versus 48 ± 6%, respectively; p = 0.02). Whole wheat bread protein digestibility was also …

Evaluating Salmonella Cross Contamination In Raw Chicken Thighs In Simulated Post-Chill Tanks, Raziya Sadat

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

Salmonella contamination poses a significant risk to food safety, particularly in poultry products and public health. This study aims to investigate the effectiveness of peracetic acid (PAA) treatment in mitigating Salmonella cross-contamination in chicken thighs within simulated post-chill tanks, considering different inoculum concentrations and organic matter (OM) levels.

The experiment involved the use of five distinct Salmonella serovars to inoculate chicken thighs, which were categorized into two groups: higher inoculation level (ca. 7 log CFU/mL) and lower inoculation level (ca, 4 log CFU/mL). These groups underwent treatment with four different solutions, including 540 ppm PAA with 1.5% OM, 540 ppm …

Cellulosome-Forming Modules In Gut Microbiome And Virome, Jerry Akresi

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

Cellulosomes are large multi-enzyme complexes encoded in the genomes of some microorganisms. Cellulosomes can degrade plant cell wall celluloses, commonly found in compost soils, forest floors and dietary fibers of farm animals. The hallmarks of cellulosome complexes are cohesins that form a large scaffoldin protein and dockerins that interact with cohesin to dock enzymes onto the scaffoldin. The dockerin-containing proteins often contain Carbohydrate Active Enzymes (CAZyme) domains, predominantly the cellulases (e.g., GH48 and GH9 enzymes), which enable them to break down celluloses. A fascinating question is, has Nature also evolved other similar protein complexes that target other types of complex …

Optimizing Soil Nutrient Management To Improve Dry Edible Bean Yield And Protein Quality, Emily Jundt

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

Soil nutrient management is of the utmost importance to ensure crop yields are maximized to feed the world’s growing population. Micro and macronutrient deficiencies can be detrimental to plant growth and cause a drastic reduction in yield. Optimization of nutrient management needs extensive research. Nutrients such as nitrogen increase crop yield, even in legumes capable of using a large amount of nitrogen (N) via biological N fixation. Iron (Fe) fertilizers are also crucial for legumes as they are susceptible to Fe deficiency induced chlorosis.

Dry edible beans (Phaseolus vulgaris) are leguminous plants and excellent dietary protein sources. Great …

Fusarium Species Structure In Nebraska Corn, Yuchu Ma

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

Fusarium species are known to infect corn and cause significant yield losses and mycotoxin contamination worldwide. In this study, we investigated the diversity of Fusarium species infecting corn in Nebraska and their potential to produce fumonisins and trichothecenes. A total of 259 Fusarium isolates were collected from different corn tissues (ear, stalk, and root), revealing a significant association between the various Fusarium species complexes and different plant parts (p < 0.05). Fusarium incarnatum-equiseti species complex (FIESC) was the most widespread and abundant, followed by the Fusarium sambucinum (FSAMSC) and Fusarium fujikuroi species complexes (FFSC). In the subsequent analysis, we investigated the mycotoxin …

Antimicrobial Efficacy Of A Citric Acid/Hydrochloric Acid Blend, Peroxyacetic Acid, And Sulfuric Acid Against Salmonella On Inoculated Non-Conventional Raw Chicken Products, Emma Nakimera

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

The utilization of non-conventional chicken parts as human food varies widely across countries. The high prevalence of Salmonella, especially in the giblets, poses a high risk to public health. Poultry processors have implemented multiple hurdle technology to reduce this gram-negative pathogen in chicken parts. This study was conducted to evaluate the antimicrobial efficacy of a commercial blend of citric acid/ hydrochloric acid (CP), peroxyacetic acid (PAA), and sulfuric acid (SA) in reducing Salmonella inoculated on two chicken giblets: livers and hearts. Chicken hearts and livers were inoculated (6 log CFU/ml of rinsate) by individually immersing them in a cocktail …

Evaluating The Efficacy Of Germination And Fermentation In Producing Biologically Active Peptides From Pulses, Ashley Newton

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

Recently, there has been a profound increase in demand of plant-based proteins, especially pulse proteins. However, pulses contain high concentrations of antinutritional factors that hinder the digestibility of proteins. Processing techniques such as enzymatic hydrolysis, microbial fermentation, and physical processing modulate nutritional quality and functionality of pulses. Processing also releases peptides from parent proteins that exhibit health-beneficial bioactivity against various disease risk factors. In this study, germination, gastrointestinal digestion, and microbial fermentation were evaluated to determine the nutritional quality and release of bioactive peptides during and after processing.

Germination of chickpeas (Cicer arietinum L.) modulated the protein profile, and …

Occurrence Of Hydroxyproline In Proteomes Of Higher Plants, Olivia Huffman

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

Food allergies affect millions of individuals across the United States and worldwide. Peanut allergies are among the most severe food allergies because of their potentially life-threatening symptoms and lifelong persistence. Potent peanut allergen, Ara h 2, is known to contain an amino acid motif containing the posttranslational modification, hydroxyproline (HyP). HyP is associated with immunogenic response when present both in Ara h 2 and in timothy grass pollen allergen, Phl p 1. To further explore the presence of HyP in higher plants and specifically to investigate its potential presence in commonly allergenic plants, a study of 26 plant seeds was …

Safety Assessment Of Novel Foods And Food Proteins, Niloofar Moghadam Maragheh

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

The global food market needs to grow and supply food demand to feed the growing world population. Alternative food proteins, including novel sources of safe foods and ingredients, are the candidates that could provide more environmentally sustainable choices, animal welfare, and consumers health. Novel foods and food proteins must undergo premarket safety evaluations including allergenicity assessment to reduce the risk of cross-reactivity with known allergens and uncharacterized risk to food allergic individuals. This research addressed the safety assessment of some novel foods and food ingredients using the study of stability of proteins in pepsin and sequence identity analysis in the …

Development Of A Targeted Mass Spectrometry Method For The Detection And Quantification Of Peanut Protein In Incurred Food Matrices, Sara Schlange

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

The unintentional presence of peanut in food products through allergen cross-contact is a considerable safety concern for peanut-allergic individuals. The food industry monitors for this contamination using immunoassays; however, these detection methods demonstrate issues with recovery and accurate quantification of allergenic protein when analyzing processed, complex food matrices. Of particular concern is the deficit in immunoassay-based detection and quantification of peanut in cookie and dark chocolate matrices, as the unintentional presence of peanut has been observed in these food products. A liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for the detection and quantification of peanut protein in cookie and …

Evaluation Of Wheat-Specific Peptide Targets For Use In The Development Of Elisa And Mass Spectrometry-Based Detection Methods, Jessica Humphrey

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

Individuals with IgE-mediated wheat allergy and celiac disease must avoid the consumption of wheat. Those with celiac disease must also avoid rye and barley in addition to wheat as these make up the gluten-containing grains. To ensure products are accurately labeled, ELISA methods may be used to monitor compliance with food allergen and gluten-free regulations. Currently, available ELISA methods for wheat detection utilize monoclonal antibodies that target peptides from the gluten fraction of proteins, and therefore, also detect rye and barley. Limitations such as differing antibody reactivity and unequal gluten content among wheat, rye, and barley have led to inconsistent …

Identification Of Gut Microbiome Composition Responsible For Gas Production, Erasme Mutuyemungu

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

Gas production remains a significant barrier to increasing intake of dietary fiber-containing foods for many consumers. Therefore, this thesis is comprised of two studies focusing on the role of the gut microbiome in contributing to gas production during fermentation of dietary components. Previous studies have reported significant correlations between Megasphaera elsdenii and gas production during fermentation of pulses. Therefore, the objective of the first study was to determine the role of M. elsdenii in gas production by the microbiome during fermentation of foods commonly associated with gas production. Human fecal microbiomes were separated based on the presence (Me+) or absence …

Comparative Assessment Of Human Exposure To Antibiotic-Resistant Salmonella Due To The Consumption Of Various Food Products In The United States, Yifan Wu

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

Antibiotic resistance (AR) was increasingly recognized as a global and national problem. Prevention efforts are hampered by a lack of complete understanding of how transmission pathways contribute to human AR exposure. Many reports have indicated the presence of antibiotic-resistant bacteria in foods at retail, suggesting that food consumption, animal-derived foods in particular, can represent a significant source of AR exposure among consumers. The presence of Salmonella, including antibiotic-resistant Salmonella, has been frequently reported in terrestrial animal-derived foods such as meat, poultry, and dairy products, as well as in aquaculture products. Identification of the significant food sources that harbor …

Differential Effects Of Protein Isolates On The Gut Microbiome Under High And Low Fiber Conditions, Marissa Behounek

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

Protein isolates are a growing market share in the food industry both as food ingredients and as supplements. All dietary habits can influence and alter the gut microbiome; however, little is known about how protein isolates from different sources will change the composition and function of the gut microbiota under high and low fiber conditions. The study aims to determine the microbiome response to plant and animal protein isolates under high- and low-dietary fiber (H/LDF) conditions. Six commercially available protein isolates (beef, egg white, milk, pea, and two soy protein isolates) were subjected to in vitro enzymatic digestion and dialysis …

Molecular Mechanisms Underlying Mucosal Attachment And Colonization By Clostridioides Difficile, Ben Sidner

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

Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium which causes gastrointestinal disease and is a leading cause of nosocomial infections. Although infection typically occurs following antibiotic therapy, in recent years there has been an increase in infections which are not preceded by antibiotic use. Additionally, community-associated infections and rates of disease recurrence have increased. While it is understood that a healthy gastrointestinal microbiota provides protection against infection, the molecular mechanisms which underly C. difficile's ability to colonize and persist in the gut are mostly unknown. Building on work from others that suggests C. difficile associates with the outer mucus …

High Pressure Processing Of Cashew Milk, Rachel Coggins

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

Plant-based foods are becoming increasingly popular because of changing consumer preferences. Most plant-based milks are not a direct replacement for cow’s milk because they do not have the same nutritional value and physicochemical properties. However, these properties could be modified and enhanced through processing. For example, high pressure processing (HPP) can affect irreversibly protein structure and functionality and potentially enhance enzymatic hydrolysis. HPP is used widely in the beverage industry for cold pasteurization. In this study, the effects of HPP treatment on (a) the inactivation of Listeria innocua, a commonly used surrogate for Listeria monocytogenes in HPP research, in …

Evaluation Of Human Microbiota-Associated (Hma) Porcine Models To Study The Human Gastrointestinal Microbiome, Nirosh D. Aluthge

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

Research conducted in the past couple of decades has showcased the importance of the gut microbiota in human health and well-being. While many studies have reported on the differences in community membership between a disease state and a healthy state, few have investigated the mechanisms through which an aberrant microbiota contributes to a disease phenotype. One of the primary reasons for this are the many technical and ethical barriers to conducting the necessary studies directly in human individuals. Human microbiota-associated (HMA) porcine models have the potential to become important research tools which can enable the testing of hypotheses regarding host-microbiota …

Evaluating The Microbial Quality And Use Of Antimicrobials In Raw Pet Foods, Leslie Pearl Cancio

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

Raw meat-based diets (RMBDs) are emerging pet foods that pose food safety risks because of the potential presence of pathogens that could cause illness to humans. In this research, the microbial quality of select RMBD products sold by pet food companies online and the use of chemical antimicrobials to reduce the microbial load in chicken liver, a common RMBD ingredient, were evaluated.

Ground meat blends and livers from four animal species (beef, pork, chicken, turkey) were purchased from four online companies that delivers directly to consumers through parcel businesses. Products were procured at three different times during one year and …

The Molecular Basis For Natural Competence In Acinetobacter, Yafan Yu

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

Bacteria use Horizontal Gene Transfer (HGT) to acquire genetic material, leading to the development of novel traits, such as the spread and development of antibiotic resistance. Natural competence is one type of HGT accomplished by DNA uptake from the environment and incorporation into the genome. Bacteria from Acinetobacter are wildly distributed in the environment and are naturally competent. This propensity is a key factor to the steady increase in drug resistance in Acinetobacter, which is a cause for concern in human health as Acinetobacter is a major source of nosocomial infections. During natural competence, type IV pili (T4P) and related …

The Application Of Mathematical Optimization And Flavor-Detection Technologies For Modeling Aroma Of Hops, Yutong Liu

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

In recent years, proprietary hops (Citra, Simcoe, and Mosaic) become the most sought-after hops among brewers due to their excellent aroma. However, they are restricted to the owners unless other growers purchase the costly licensing agreements. Many public hops are available to the growers without any additional costs, but their aroma is difficult to match to the proprietary hops. Although proprietary and public hop varieties are unique in their aroma profiles, all hops varieties contain similar volatile compounds, merely differ in the quantity of different individual compounds. The main objective of this thesis was to investigate the feasibility of matching …

Risk Based Simulations Of Sporeformers Population Throughout The Dairy Production And Processing Chain: Evaluating On-Farm Interventions In Nebraska Dairy Farms, Rhaisa A. Crespo Ramírez

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

Sporeformer bacteria are ubiquitous in the farm environment. These bacteria produce enzymes that negatively affect the quality of dairy products representing a problem for the dairy industry. Two major issues associated with high levels of sporeformers in raw milk are shelf-life reduction of fluid milk and market limitations for milk powder. Specific attention has been given to the contamination of milk powders with sporeformers due to their ability to survive pasteurization and milk powder processing conditions. Hence, the control of sporeformers is crucial to benefit the whole dairy industry. Researchers have suggested that certain management practices could decrease sporeformers in …

Dietary Fiber Utilization In The Gut: The Role Of Human Gut Microbes In The Degradation And Consumption Of Xylose-Based Carbohydrates, Elizabeth Drey

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

Xylans are a family of xylose-based polysaccharides naturally present in fruits, vegetables, and cereal grains. Resistant to digestion by host enzymes, xylans reach the large intestine intact, where they are utilized by members of the gut microbiome. They are initially hydrolyzed by primary degraders that utilize extracellular xylanases to cleave xylan into smaller oligomers. These xylooligosaccharides (XOS) can then either be further hydrolyzed by primary degraders or can cross-feed secondary consumers, including Bifidobacterium. While several Bifidobacterium species have metabolic systems for XOS, studies have shown these species grow poorly on longer XOS and xylan substrates. In this thesis, …

Synthesizing Inactivation Efficacy Of Treatments Against Bacillus Cereus Through Systematic Review And Meta-Analysis And Evaluating Inactivation Efficacy Of Commercial Cleaning Products Against B. Cereus Biofilms And Spores Using Standardized Methods, Minho Kim

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

Bacillus cereus is ubiquitous and can be easily carried in food processing facilities. It is problematic because it can survive various treatments such as heat, radiation, and chemical cleaning by forming spores and biofilms. Some review papers have discussed inactivation efficacies of different treatments against B. cereus, but they are narrative without quantitative summaries. This study first aimed to find effective and food industry-applicable treatment candidates against B. cereus spores and biofilms by synthesizing and comparing the efficacy of treatments using systematic review and meta-analysis. After screening, 17 studies were included, but only nine studies were used for meta-analysis …

Studies On Milling And Baking Quality And In-Vitro Protein Digestibility Of Historical And Modern Wheats, Sujun Liu

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

There is considerable controversy among the public and the scientific community about whether modern wheats are harmful for human health and responsible for the increase of Celiac disease compared with historical varieties. Therefore, the milling and baking quality, protein digestibility, and protein composition of historical and modern wheats adapted to the Great Plains of the US were evaluated in this thesis. One objective of this thesis was to determine how end-use quality of wheat changed with wheat cultivar release year. Kernel physical characteristics, milling yield, whole-wheat flour quality, flour protein content, mixing quality and baking quality of 23 hard winter …

Effect Of Radiofrequency Assisted Thermal Processing On The Structural, Functional And Biological Properties Of Egg White Powder, Alisha Kar

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

Radiofrequency (RF) assisted thermal processing is a novel and energy-efficient method used for pasteurization, which heats the product volumetrically as opposed to traditional hot room (HR) pasteurization. RF-assisted thermal processing accelerates the heating rate of egg white powder (EWP), which has a low thermal conductivity and further affect its gelling properties. The effect of processing methods (RF and HR) due to pH and treatment temperature combination was monitored by subjecting neutral EWP (6.4 pH) to 70 and 80 ℃ and alkaline EWP (pH 9.9) samples to 70 ℃ over 0, 5, 10, 15 and 20 d. At 80 ℃ and …

Pre-Milling Interventions For Improving The Microbiological Quality Of Wheat, Shpresa Musa

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

Development of pre-milling intervention strategies to improve the microbial quality of wheat and wheat-based products is an emerging concern for the food industry. When steam tempering conditions for hard and soft wheat were applied, the microbial population associated with the grain was significantly reduced compared to controls. Further reductions were observed when acid was applied as part of the intervention which is an added benefit since the addition of a tempering solution is required for both wheat classes since the desired milling moisture cannot be reached by applying steam alone. On average, the highest reductions for hard wheat were achieved …

Understanding The Roles Of Nutrient-Niche Dynamics In Clostridioides Difficile Colonization In Human Microbiome Colonized Minibioreactors, Xiaoyun Huang

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

Clostridioides difficile is a Gram-positive pathogen that is one of the most common causes of health care-associated infections in the U.S. Because of its importance to human health, researchers are trying to understand risk factors for infection and identify new therapies to treat disease. A “healthy” gut microbiome has the ability to protect the host against colonization of C. difficile or other pathogens by providing colonization resistance. One proposed mechanism for colonization resistance is through competition for nutrients with pathogens by the members of the healthy microbiome. We tested whether competition for nutrients was important for colonization resistance in human …

Investigating The Prevalence And Control Of Listeria Monocytogenes In Food Facilities, Cyril Nsom Ayuk Etaka

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

Small and very small food facilities in the ready-to-eat food industry face difficulties complying with the Food Safety Modernization Act-Preventive Controls for Human Food rule (FSMA-PCHF). This regulation highlights the need for sanitation to control environmental pathogens like Listeria monocytogenes. The main goal of this project was to investigate the prevalence and control of Listeria monocytogenes in food facilities. This study provides technical assistance to facilities to comply with the PCHF rule and addresses sanitation alternatives for food contact surfaces like aqueous ozone.

First, the prevalence of Listeria spp and L. monocytogenes in small and very small food manufacturing …

The Differences Of Prokaryotic Pan-Genome Analysis On Complete Genomes And Simulated Metagenome-Assembled Genomes, Tang Li

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

Metagenomic assembly is often used in microbiome research. In metagenomic assembly, contigs are binned based on the shared nucleotide composition. These contig bins are called metagenome-assembled genomes (MAGs), each representing a unique bacterial genome recovered from metagenome sequencing. Hundreds of thousands of high-quality MAGs of various ecological environments have been published since 2017, and increasingly more MAGs are being used in pan-genome analyses where unculturable species or species without reference genomes are studied in microbiome research. However, compared to the traditional pan-genome analysis that uses isolate genomes (from a pure strain isolated from a mixed bacterial population), it is not …