Food Microbiology Commons^™

Microbial Challenge Studies Of Radio Frequency Heating For Dairy Powders And Gaseous Technologies For Spices, Xinyao Wei

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

Persistence, thermal resistance, and survival of Salmonella in low moisture foods (LMF) have resulted in several foodborne illness outbreaks. Both existing and novel pasteurization technologies need to be validated for microbial safety of LMF. In this dissertation, a framework for using radio frequency (RF) heating to enhance microbial safety of milk powders and egg white powder was established. Thermal inactivation kinetics of Salmonella in milk powders were determined to guide the dairy industry for identifying thermal processing conditions for pasteurization. Storage time showed no effect on the thermal resistance of Salmonella, which can simplify the process validation study in …

Process Interventions For Improving The Microbiological Safety Of Low Moisture Food Ingredients, Tushar Verma

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

The recurrence of Salmonella in low moisture foods and the implementation of the FSMA rule requires a need to validate legacy and novel processing technologies. In this dissertation, a legacy thermal (extrusion), a novel thermal (radiofrequency (RF) heating), and a non-thermal (chlorine dioxide) technology, were evaluated as intervention technologies for Salmonella in low moisture foods. The twin-screw extruder was performed at different levels of screw speeds, temperatures, moisture contents, and fat contents to understand the impact of processing conditions on Salmonella inactivation in oat flour. At temperature >65°C, the Salmonella population was below the detection limit. At 55°C, Salmonella reduction …

16s Rrna Gene Sequence Analysis Of Acetic And Lactic Acid Bacteria Isolated From Philippine Sugarcane Wine (Basi) [Research Note], John Russel G. Sevilla, Michael Angelo S. Esteban, Honey Bhabes R. Iñigo, Audrey May V. Orillaza, Baby Richard R. Navarro

The Philippine Agricultural Scientist

Basi, a traditional sugarcane wine of the Philippines, was studied. Here, we used molecular- and cultural-based methods to isolate, identify and characterize acid-producing bacteria, specifically acetic and lactic acid bacteria, from basi. Acid producers were focused on owing to the rapid spoilage of basi via acidification with air exposure. Two strains each of acetic and lactic acid bacteria were isolated. DNA was extracted from these isolates. PCR-amplified DNA products were subjected to 16S rRNA gene sequencing. The sequences of the isolates were then aligned with BLAST database sequences and found to have high similarities to Acetobacter malorum (99%), …

Effect Of Contact Time And Attachment Level Of Bacterial Pathogens On Efficacy Of Chlorine Treatment In Fresh Produce, Jyoti Aryal

LSU Master's Theses

Bacterial attachment or biofilm formation on produce surfaces may result in limited penetration ability of sanitizers. This study examined the wet and dry contact time (WCT or DCT) of produce during washing with sanitizer and evaluated the effect of attachment level of Listeria monocytogenes during storage on the efficacy of chlorine treatment. Spinach and bell peppers were inoculated with Listeria monocytogenes and Salmonella enterica. The produce was then washed by dipping into a 100 ppm of chlorine solution for 1 min and an additional 1, 3, or 5 minutes (WCT) or removed from the chlorine solution and held for 1, …

Food Analysis Module Descriptor With Sdgs Embedded, Julie Dunne

Reusable Resources

This OER is a Food Analysis module descriptor that has been reviewed to embed sustainability learning outcomes, activities, and reading material. This is an output from the IMPACT project Sustainable-Food-Curriculum CoCreate. It includes learning outcomes related to green chemical analysis, and impact of climate change on food analysis.

Effect Of Simulated Storage And Distribution On Listeria Innocua Growth In Non-Traditional Salad Ingredients, Emma L. Sandquist

Master's Theses

The fresh-cut produce industry has seen expansive growth in recent years, to meet consumer demand ready-to-eat (RTE) salads have included the use of non-traditional ingredients. Uncommon ingredients include beet greens, kale, broccoli stalk, and Brussels sprouts, since these ingredients have not historically been consumed raw, potential food safety issues should be reassessed. Current processing technologies include produce washes that can reduce microbial levels but do not eradicate all populations. The lack of a kill step in produce processing emphasizes the need to minimize pathogen contamination during production and growth during a product’s shelf life. Listeria monocytogenes, a leading cause …

Improving Nutritional Properties And Extractability Of Pea Proteins For Human Consumption Via Fungal Bioprocessing, Camille Massmann

Electronic Theses and Dissertations

Yellow peas are a rich source of protein and phytochemicals. Peas are compatible with many diets restricted by sensitivities, allergies, or personal choice. As a result, peas are gaining popularity in food markets, despite the challenges they present. The biggest challenges for pea proteins in food markets are high content of fiber, starch, and saponins. These components cause processing challenges and create undesirable textures and bitter flavors. Pea proteins are typically extracted with alkaline extraction or air classification methods which result in 80% and 50% protein products respectively. With low protein purity, these products are not competitive with other, more …

Investigation Of Fermentation Efficiency In Saccharomyces Cerevisiae Through Telomere Integrity And Maltase Expression, Dana Bennett

All Graduate Theses, Dissertations, and Other Capstone Projects

Many microbreweries practice serial fermentation, or serial repitching. Serial repitching is the process by which one yeast culture is reused for multiple batches of beer. Each batch of subsequent beer is called a “pitch.” This technique helps breweries limit production costs. However, fermentation is difficult to predict throughout serial fermentation. This leads to beer quality issues such as fluctuation in alcohol production, buildup of unwanted flavor compounds, and decreased carbon dioxide production, which results in reduced profit. To combat this issue, many breweries will attempt to predict fermentation efficiency through viable cell counting in order to ensure a consistent number …

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 …

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 …

Green Fractionation Of 2g And 3g Feedstocks For Ethanol Production: Advances, Incentives And Barriers, Behzad Satari, Amit Jaiswal

Articles

Efficient release of fermentable sugars from the complex biomass structure such as second-generation or third-generation feedstocks by an appropriate enzymatic hydrolysis needs a prior biomass fractionation. This process facilitates the exposure of more cellulose and hemicelluloses for enzymatic hydrolysis. This review focused on ‘green fractionation’ of biomass by applying the principles of green chemistry for bioethanol production. Besides, the recent technological achievements in applying these principles for the fractionation have been discussed. For green fractionation, energy delivery systems are referred to as microwave and ultrasound. Besides, green cellulose solvents, biomass-derived solvents, and supercritical carbon dioxide play an important role in …

Non-Sterile Fermentation Of Food Waste Using Thermophilic And Alkaliphilic Bacillus Licheniformis Ynp5-Tsu For 2,3-Butanediol Production, Joshua A. O'Hair, Qing Jin, Dajun Yu, Jian Wu, Hengjian Wang, Suping Zhou, Haibo Huang

Agricultural and Environmental Sciences Faculty Research

Conversion of food waste into 2,3-butanediol (2,3-BDO) via microbial fermentation provides a promising way to reduce waste disposal to landfills and produce sustainable chemicals. However, sterilization of food waste, an energy- and capital-costly process, is generally required before fermentation to avoid any contamination, which reduces the energy net output and economic feasibility of food waste fermentation. In this study, we investigated the non-sterile fermentation of food waste to produce 2,3-BDO using a newly isolated thermophilic and alkaliphilic B. licheniformis YNP5-TSU. Three unitary food waste samples (i.e., pepper, pineapple, cabbage wastes) and one miscellaneous food waste mixture were respectively inoculated with …

Evaluation Of Listeria Innocua Transfer From Personal Protective Equipment (Ppe) To The Plant Environment And Effective Sanitation Procedures To Control It In Dairy Processing Facilities, Karen Nieto

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

Listeria monocytogenes can survive and grow under wet environmental conditions encountered in dairy facilities. Pasteurization of milk kills L. monocytogenes; however, recent listeriosis outbreaks have linked post-pasteurization contamination from the food environment to the final product. One of the sources of microbial contamination may include employees and their personal protective equipment (PPE), which often become in contact with equipment and food contact surfaces. To understand this issue, this study evaluates Listeria innocua, as a surrogate for Listeria monocytogenes, transfer from PPE to food products and surfaces encountered in dairy plants. Gloves, aprons, and boots were inoculated with L. …

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, …

Observed Defects Of Swiss Cheese Based On The Microbiome Contribution To The Production Of Organic Acids, Vannessa D. Campfield

Boise State University Theses and Dissertations

The United States Department of Agriculture downgrades on the order of 17% of all Swiss cheese produced in the United States due to defects. Many of these defects are related to improper eye formation, number, distribution, or size; leading to an industry loss of over $69 million per annum. The microbiome in Swiss-type cheeses plays a significant role in eye development due to production of organic acids and gaseous emissions contingent on bacterial abundance and phenotype. The relationship between bacteria and the organic acids they produce leading to Swiss cheese defects can be correlated using Next-generation sequencing and high-performance liquid …

An Impedimetric Aptasensing System For The Rapid Detection Of Salmonella Typhimurium, America Sotero

Graduate Theses and Dissertations

Salmonella Typhimurium is a foodborne pathogen associated with raw and undercooked eggs, poultry, beef, fruits, and vegetables. In the United States, Salmonella is responsible for approximately 1.2 million illnesses, 23,000 hospitalizations, and 450 deaths annually. For many years, conventional detection methods such as culture-dependent and PCR-based methods have been the “golden standards” for the detection of this pathogen due to their high sensitivity and reliability. However, they still have some disadvantages such as long enrichment steps and high costs that need to be overcome. The development of a rapid and reliable method for the detection of S. Typhimurium is needed …

Development Of Novel Pectinase And Xylanase Juice Clarification Enzymes Via A Combined Biorefinery And Immobilization Approach, Shady Hassan

Doctoral

Hydrolytic enzymes, such as pectinase and xylanase, maybe harnessed for numerous industrial applications in food industry. Therefore, economic factors such as achievement of optimum yieldsandoverall production costs, in addition to biocatalyst instability,are the main obstacles tothe industrial production and exploitation of a enzymes. For example, microbially-derived enzymes are typically produced in fermenters using expensive growth media, which may account for 30 to 40% of the production cost, and such expense may be compounded further by downstream processing operations.To counter such disadvantages, the major trend in industrial utilization of enzymes in cost-sensitive processes has been to immobilize such biocatalysts on a …

Assessment Of Grain Safety In Developing Nations, Jose R. Mendoza

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

Grains are the most widely consumed foods worldwide, with maize (Zea mays) being frequently consumed in developing countries where it feeds approximately 900 million people under the poverty line of 2 USD per day. While grain handling practices are acceptable in most developed nations, many developing nations still face challenges such as inadequate field management, drying, and storage. Faulty grain handling along with unavoidably humid climates result in recurrent fungal growth and spoilage, which compromises both the end-quality and safety of the harvest. This becomes particularly problematic where there is little awareness about health risks associated with poor …

An Agent-Based Simulator For The Gastrointestinal Pathway Of Listeria Monocytogenes, Ashrafur Rahman, Ali Asgary, Daniel Munther, Aamir Fazil, Ben A. Smith, Jianhong Wu

Mathematics and Statistics Faculty Publications

We developed an agent-based gastric simulator for a human host to illustrate the within host survival mechanisms of Listeria monocytogenes. The simulator incorporates the gastric physiology and digestion processes that are critical for pathogen survival in the stomach. Mathematical formulations for the pH dynamics, stomach emptying time, and survival probability in the presence of gastric acid are integrated in the simulator to evaluate the portion of ingested bacteria that survives in the stomach and reaches the small intestine. The parameters are estimated using in vitro data relevant to the human stomach and L. monocytogenes. The simulator predicts that 5%–29% of …

Dynamic Between Biomass, Ph And Acid Lactic By Microorganisms In Fermentation Of Fresh Milk, Emmanuel Rodriguez, Aurelio Castillo, Paul A. Valle, Yolocuauhtli Salazar

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Chemical Effects Of Cold Atmospheric Plasma On Food Nutrients, Juan Manuel Pérez Andrés

Doctoral

A range of nonthermal techniques have demonstrated process efficacy in ensuring food product safety, extension of shelf-life and in general a retention of key quality attributes. However, various physical, chemical and biochemical effects of nonthermal techniques on both macro and micronutrients are evident, leading to both desirable and undesirable changes in food products. It is important to outline the effects of non-thermal techniques on food chemistry and the associated degradation mechanisms with the treatment of foods. Oxidation is one of the key mechanisms responsible for undesirable effects induced by non-thermal techniques. Degradation of key macromolecules largely depends on the processing …

Development Of Essential Oil Incorporated Active Film Based On Biodegradable Blends Of Poly (Lactide)/Poly (Butylene Adipate‑Co‑Terephthalate) For Food Packaging Application, Shubham Sharma, Sandra Barkauskaite, Swarna Jaiswal, Brendan Duffy, Amit Jaiswal

Articles

Active packaging improves food safety and quality with the incorporation of certain additives such as antimicrobial agents. The PLA/PBAT films were prepared with two essential oils—eucalyptus oil and cinnamon oil of various concentrations (1%, 5%, and 10% w/w) and characterized their optical and mechanical properties, surface hydrophobicity, chemical composition, and antimicrobial activity. Cinnamon oil composite films were observed as thicker films (88.88 µm) than the eucalyptus oil films (54.46 µm). The highest UV-blocking properties were observed in cinnamon oil films. However, transparency and tensile properties of the cinnamon oil films decreases as the concentration increases. The tensile strength of the …

Characterization And Antimicrobial Activity Of Biodegradable Active Packaging Enriched With Clove And Thyme Essential Oil For Food Packaging Application, Shubham Sharma, Sandra Barkauskaite, Brendan Duffy, Amit Jaiswal, Swarna Jaiswal

Articles

Bioactive packaging contains natural antimicrobial agents, which inhibit the growth of microorganisms and increase the food shelf life. Solvent casting method was used to prepare the Poly (lactide)-Poly (butylene adipate-co-terephthalate) (PLA-PBAT) film incorporated with the thyme oil and clove oil in various concentrations (1 wt%, 5 wt% and 10 wt%). The clove oil composite films depicted less green and more yellow as compared to thyme oil composite films. Clove oil composite film has shown an 80% increase in the UV blocking efficiency. The tensile strength (TS) of thyme oil and clove oil composite film decreases from 1.35 MPs (control film) …

Performance Of A Uv-A Led System For Degradation Of Aflatoxins B1 And M1 In Pure Water: Kinetics And Cytotoxicity Study, Judy Stanley, Ankit Patras, Brahmaiah Pendyala, Matthew J. Vergne, Rishipal R. Bansode

Agricultural and Environmental Sciences Faculty Research

The efficacy of a UV-A light emitting diode system (LED) to reduce the concentrations of aflatoxin B1, aflatoxin M1 (AFB1, AFM1) in pure water was studied. This work investigates and reveals the kinetics and main mechanism(s) responsible for the destruction of aflatoxins in pure water and assesses the cytotoxicity in liver hepatocellular cells. Irradiation experiments were conducted using an LED system operating at 365 nm (monochromatic wave-length). Known concentrations of aflatoxins were spiked in water and irradiated at UV-A doses ranging from 0 to 1,200 mJ/cm2. The concentration of AFB1 and AFM1 was determined by HPLC with fluorescence detection. LC–MS/MS …

Exploring The Connection Between Acid Exposure And Virulence In Listeria Monocytogenes, Minghao Li

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Listeria monocytogenes is a gram-positive food-borne pathogen that is widely dispersed in the environment and can cause listeriosis with high fatality rates when consumed in contaminated food products. They are capable of growing over a wide range condition. Listeria is also able to tolerate adverse conditions which allows the bacterium to survive in unfavorable environments. The ubiquitous nature of L. monocytogenes makes it difficult to eliminate from food systems. One major problem in the food industry is the survival of L. monocytogenes under sublethal low pH-environment since organic acids are widely used as food decontaminants. Prior research has suggested that …

Effect Of Long Pasteurization Run Times On Bacterial Numbers In Milk, Brynli Tattersall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was funded by the Western Dairy Center to understand how long a milk pasteurizer can be operated before increases in bacterial numbers are observed in the pasteurized milk. While pasteurization kills pathogenic bacteria there are some non-pathogenic bacteria that can survive and have the ability to become attached to the surfaces in the cooling sections of the pasteurizer. Some bacteria can also produce spores that survive pasteurization even if the bacterial cells are killed. Temperatures in the cooling section remain in a range suitable for growth of these heat-tolerant bacteria and can allow germination of bacterial spores. While …

Improving Microbiological Safety Of Low Moisture Food Products Using Radio Frequency And Ethylene Oxide, Long Chen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Recent foodborne illness outbreaks in US associated with consumption of low-moisture foods (LMF) have heightened concerns of their microbial safety. Salmonella is a pathogen of major concern in LMF due to its ability to persist in low water activity (a_w) environments. The disadvantages of existing decontamination technologies for LMF call for novel and efficient intervention technologies. Radio frequency (RF) and ethylene oxide (EtO) were evaluated in this dissertation for improving microbial food safety and quality of LMF. Cumin seeds and inshell hazelnuts were selected as model foods.

It took < 2 min of stationary RF heating to achieve > 5 log reductions of Salmonella in cumin seeds without …

Authentication Of Red Snapper (Lutjanus Campechanus) Fillets Using A Combination Of Real-Time Pcr And Dna Barcoding, Rachel B. Isaacs, Rosalee S. Hellberg

Food Science Faculty Articles and Research

Red snapper (Lutjanus campechanus) is a historically overfished and highly valued species that is commonly substituted with other fish, such as tilapia, rockfish, and other snapper species. The objective of this study was to assess the ability of real-time PCR to be used as a screening tool to rapidly test commercial fillets for the presence of red snapper, followed by species identification of negative samples with DNA barcoding. A total of 24 frozen, fresh, or thawed (previously frozen) fillets labeled as “red snapper” were tested with real-time PCR, along with 54 fillets from fish that are common substitutes …

Phylogenetic Diversity Of Arkansas Vineyard And Wine Microbiota, Natacha Cureau

Graduate Theses and Dissertations

Microorganisms inhabiting the soil, leaves, and grapes in vineyards influence the terroir, a set of environmental factors that impact wine characteristics. Previously, the main method to identify microorganisms was to culture on different media, but a large portion (> 99%) could not be cultured and were consequently unidentified. However, the emergence of new molecular tools has enabled further study and identification of microorganisms such as indigenous vineyard microbiota. The objective of this research was to investigate the phylogenetic diversity of Arkansas vineyard and wine microbiota using high-throughput sequencing. In terms of the Arkansas vineyards, the fungal and bacterial diversity of …

Investigating The Potential Of Sodium Butyrate To Control Salmonella Enteritidis In Poultry, Anamika Gupta

Graduate Theses and Dissertations

Salmonella Enteritidis (SE) is a major poultry associated food borne pathogen that causes enteric illnesses in humans. Despite using various pre-harvest and post-harvest intervention strategies to reduce Salmonellosis, SE infection is still an extensive problem in the poultry industry with increased incidences since SE has developed multiple strategies to adapt in the chicken intestinal tract particularly in the ceca. Therefore, reducing SE in the intestine of chickens would reduce contamination of poultry derived foods and minimize the risk of human infection. Short chain fatty acids such as butyrate are microbial metabolites known to modulate inflammatory response. In this dissertation, the …