Food Science Commons^™

Rapid Detection Of Viable Salmonella Based On Specific Phage Infection Combined With Fluorescent Rpa, Liu Daofeng, Zhai Yujie, Tan Yucheng, Shan Shan, Lu Jun, Zhong Ziqing

Food and Machinery

[Objective] To establish a rapid detection method for viable Salmonella based on specific phage infection and recombinase polymerase amplification (RPA) in response to the key challenge that traditional molecular biological detection methods have difficulty in conveniently distinguishing between viable and non-viable foodborne pathogens. [Methods] Taking advantage of the characteristic that O-1 phage only proliferates in viable bacteria, the phage is added to the enriched sample. After further incubation, total DNA is extracted. Fluorescent RPA is used to determine whether the phage has significantly proliferated, so as to judge the presence of viable Salmonella in the original sample. [Results] After optimization, …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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

Micro-Greens, Not Micro-Yellows: Evaluating Dehydration-Based Preservation Techniques For Reducing Foodborne Pathogens And Quality Preservation On Microgreens, Travis S. Sananikone

Graduate Theses and Dissertations

Microgreens are increasingly popular among consumers due to their high nutritional value. However, their limited shelf-life remains a significant challenge. To extend their usability, small-scale growers increasingly apply home preservation methods like warm air drying or freeze-drying. However, the effects of these methods on common foodborne pathogens are not well understood. Radish and alfalfa microgreens were inoculated with cocktails of Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes 4b (ca. 8.0 log CFU/g). Treatments included dehydration in a commercial dehydrator, freeze-drying (-20°C, 24 h), and convective drying in an oven (60°C for 4 h), and convective drying in an oven …

Crispy Not Risky: Effects Of Environmental Conditions On Low-Moisture Food Persistent Bacterial Pathogens, Manita Adhikari

Graduate Theses and Dissertations

Low-moisture foods (LMFs) were not historically seen as safety risks due to their ability to inhibit pathogen growth, but evidence shows pathogens can survive in LMFs long-term, causing outbreaks and recalls. Previous studies have lacked the ability to replicate real-world contamination scenarios in LMF processing environments. This research aimed to develop inoculation methods to form LMF persistent bacterial populations (LMF PBPs) and assess pathogen responses to environmental factors, culturing methods (broth vs. lawn), and matrix type and ratio. Inoculation methods tested were “direct” (combining bacterial culture and powder on a stainless-steel coupon) and “slurry” (premixing culture and powder). Matrices included …

A Systematic Review And Meta-Analysis Of Chemical Sanitizer Efficacy Against Biofilms Of Listeria Monocytogenes, Salmonella Enterica, And Stec On Food Processing Surfaces, Allyson N. Hamilton, Sarah L. Jones, Christopher A. Baker, Xinya Liang, Adam Siepielski, Ashlynn Robinson, Gayatri R. Dhulappanavar, Kristen E. Gibson

Food Science Faculty Publications and Presentations

Chemical sanitizers are applied to food processing surfaces to inactivate bacterial pathogens. Pathogen type, surface type along with sanitizer type, concentration, and contact time are important factors potentially impacting sanitation efficacy. Numerous studies on chemical agents and lab-generated biofilms have been published; however, cross-study comparisons can be difficult. A systematic literature review (SLR) and meta-analysis were conducted to evaluate chemical sanitizer efficacy against Listeria monocytogenes, Salmonella spp., and Shiga toxin-producing Escherichia coli (STEC) within lab-generated biofilms on food contact surfaces (FCSs). The SLR included 13 peer-reviewed articles published between 2000 and 2020. Sanitizer concentration, type, contact time, surface type, and …

Inactivation Of E. Faecium Nrrl B-2354 In Whole Black Pepper By Fluidization With Hydrogen Peroxide Vapor, Daniela Segura

Department of Food Science and Technology: Master of Science with Project Option

This study evaluated Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella inactivation in black peppercorns treated with hydrogen peroxide (HP) vapor via fluidization. The selected parameter for dwell temperature was 60ºC for 60 minutes. The reduction of both Salmonella and E. faecium, along with changes in water activity, color, and residual hydrogen peroxide, were measured before, immediately after treatment and at 24 and 48 hours post-treatment. Results showed that E. faecium exhibited a significantly greater reduction (4.63 ± 0.55 log CFU/g) compared to Salmonella (2.94 ± 0.16 log CFU/g) (p < 0.05), making E. faecium unsuitable as …

Lactobacillus Rhamnosus Interactions With Foodborne Pathogens And Impact On Plant Productivity In A Model Hydroponic System, Esther Titilope Oginni

Theses and Dissertations

Food production is a global problem, and this has been further compounded with changes in weather patterns necessitating the need for a sustainable approach to production. Chapter 1 introduces the broad concept of the Control environment agriculture (CEA) and then narrows it doe to the hydroponic system its food safety risks. The CEA has been employed alongside conventional practices methods to improve meet the demand for food without placing pressure on the land available. Foodborne outbreaks have been recorded in the production medium and are therefore susceptible to contamination. In Chapter 2, the study focused on using Lactobacillus rhamnosus and …

Gaseous Ozone To Improve The Microbial Safety Of Spices, Seeds, And Nuts, Arshpreet Kaur Khattra

Graduate Theses and Dissertations

Due to the increasing number of reported outbreaks of pathogens in low-moisture foods (LMFs), there is a need to investigate novel non-thermal gaseous technologies to increase the microbiological safety of spices, nuts, and seeds without compromising the product quality. The objective of this study was to inactivate Salmonella spp. in different spices, seeds, and nuts using gaseous ozone treatment and evaluate the suitability of Enterococcus faecium as a potential surrogate for Salmonella. Each food product (dried basil leaves, black peppercorn, chia seeds, and walnuts) was separately inoculated with a 5-strain Salmonella and E. faecium cocktail and equilibrated to water activity …

Salmonella Detection In Food Using A Hek-Htlr5 Reported Cell-Based Sensor, Esma Eser, Victoria A. Felton, Rishi Drolia, Arun K. Bhunia

Biological Sciences Faculty Publications

The development of a rapid, sensitive, specific method for detecting foodborne pathogens is paramount for supplying safe food to enhance public health safety. Despite the significant improvement in pathogen detection methods, key issues are still associated with rapid methods, such as distinguishing living cells from dead, the pathogenic potential or health risk of the analyte at the time of consumption, the detection limit, and the sample-to-result. Mammalian cell-based assays analyze pathogens’ interaction with host cells and are responsive only to live pathogens or active toxins. In this study, a human embryonic kidney (HEK293) cell line expressing Toll-Like Receptor 5 (TLR-5) …

Radiofrequency Inactivation Of Salmonella In Black Pepper And Dried Basil Leaves Using In-Package Steaming, Surabhi Wason, Rossana Villa-Rojas, Jeyamkondan Subbiah

Department of Food Science and Technology: Faculty Publications

Radiofrequency (RF) heating has been extensively studied for pasteurizing low‐moisture foods. Currently, bulk foods are treated with radiofrequency; potential cross‐contamination may occur during packaging of pasteurized products. As an alternative, in‐package RF processing was evaluated for Salmonella inactivation on black peppercorns and dried basil leaves and prevention of cross‐contamination during storage postprocessing. Inpackage steaming refers to the process in which the samples were heated in a steam vent package to generate and retain steam during the treatment. This treatment achieved good heating uniformity which could be because of the circulation of steam within the package. One‐way steam vent allowed the …

Growth Of Food-Borne Pathogens Listeria And Salmonella And Spore-Forming Paenibacillus And Bacillus In Commercial Plant-Based Milk Alternatives, Klaudia Bartula

ORBioM (Open Research BioSciences Meeting)

An increase in vegan diet preference, lactose intolerance, calorie concern and environmental awareness has led to a rise in the popularity of plant-based alternatives to bovine milk. However, there are still gaps in understanding how known bacterial food contaminants behave in plant-based beverages. The present study is the first to compare the growth of food-pathogens Listeria monocytogenes and Salmonella enterica, food spoilage Bacillus subtilis and an industrial milk product isolate, spore-forming Paenibacillus in commercially available ultrahigh temperature processed bovine milk and plant-based milk alternatives (coconut, almond, cashew). Beverage samples were inoculated with a strain cocktail or individual strains of either …

Radiofrequency And Gaseous Technologies For Enhancing The Microbiological Safety Of Low Moisture Food Ingredients, Surabhi Wason

Graduate Theses and Dissertations

High heat resistance and long survival of Salmonella in low moisture food ingredients (LMFIs) such as spices and seeds are concerning as they are typically consumed without cooking. Therefore, it is challenging to effectively inactivate pathogenic bacteria without negatively impacting the quality of the treated product. This dissertation aimed to develop and evaluate novel intervention technologies: in-package radiofrequency steaming and non-thermal gaseous technologies to improve the microbial safety of LMFIs. The dissertation can be divided into three parts. The first part of this dissertation on the thermal inactivation kinetics of Salmonella and a surrogate, Enterococcus faecium NRRL B-2354on black pepper …

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 …

Microbiological Safety And Quality Of Ceviche, Poke, And Sushi Dishes Sold At Retail Outlets In Orange County, Ca, Grace E. Marquis, Samantha M. Covaia, Amanda M. Tabb, Courtney J. Kitch, Rosalee S. Hellberg

Food Science Faculty Articles and Research

Raw, ready-to-eat (RTE) seafood products, such as ceviche, poke, and sushi, have experienced growing demand globally; however, these products have the potential to be contaminated with foodborne pathogens. The objective of this study was to determine the prevalence of Escherichiacoli/coliforms, Salmonella, and Listeria in ceviche, poke, and sushi dishes sold at the retail level in Orange County, CA, USA. Additional organisms detected during testing were also considered in the results. A total of 105 raw, RTE samples of ceviche, poke, and sushi were collected from restaurants and grocery stores in Orange County, CA. Samples were tested for Salmonella …

Inhibiting Survival Of Salmonella During Desiccation Through The Use Of Naturally Occurring Signals, Joseph Headrick

Electronic Theses and Dissertations

A rising problem in agriculture is the increase of antibiotic-resistant Salmonella cases associated with chicken eggs, which transmit infection to humans. To counter this, new approaches to combat Salmonella in chickens and desiccated on eggshells are vital in the prevention of human foodborne illness. Disrupting signaling pathways with naturally occurring compounds provides a potential novel avenue for prevention of Salmonella infections, as this would disrupt sensing of these environments and inhibit subsequent optimal gene expression. Starting with signals identified in previous studies, salicylic acid was found to inhibit Salmonella desiccation survival on both eggshells and plastic. To expand upon this, …

Filth Flies As A Vector For Some Pathogenic Bacteria Transfer, Ahmet Buyukyavuz

All Dissertations

Two separate sets of experiments were conducted to determine the transfer of bacteria by flies. An Escherichia coli ampicillin-resistant strain with a fluorescent gene was used during the experiments. The first set of experiments were divided into two trials to measure the transfer of E. coli by fruit flies to apple slices and bologna during short term exposure. Short time exposure (1, 5 and 15 min) of flies to inoculated apple slices were tested in the first trial to determine the transfer of E. coli to flies. No difference (P>0.05) in the number of bacteria transferred to flies were …

A New Method For Reducing Salmonella In Poultry Meat, Regis Yizerwe

Honors Program: Senior Projects (Public)

An important approach to decreasing the transmission of Salmonella into the food chain is to treat raw chicken after processing. This can be, and has been done, by using antibiotics and chemical disinfectants. Using antibiotics is not a viable option due to the issue of antimicrobial resistance. Although some chemical disinfectants have been used effectively, they are restricted due to the amounts that can be used safely, the acceptance of their use and resistance to implementation in various parts of the world. This study has revealed that using a naturally occurring saponin–Quillaja Saponaria– in small concentrations under certain conditions of …

Use Of Organic Acid Mixtures Containing 2-Hydroxy-4-(Methylthio) Butanoic Acid (Hmtba) To Mitigate Salmonella Enterica, Shiga Toxin-Producing Escherichia Coli (Stec) And Aspergillus Flavus In Pet Food Kibbles, Aiswariya Deliephan, Janak Dhakal, Bhadriraju Subramanyam, Charles G. Aldrich

Department of Food Science and Technology: Faculty Publications

Post-processing operations of extruded pet food kibbles involve coating the product with fats and flavorings. These processes increase the risk for cross-contamination with food-borne pathogens such as Salmonella and Shiga toxin-producing Escherichia coli (STEC), and mycotoxin-producing molds such as Aspergillus spp. after the thermal kill step. In this study, the antimicrobial effects of two types of organic acid mixtures containing 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), Activate DA™ and Activate US WD-MAX™, against Salmonella enterica, STEC and Aspergillus flavus when used as a coating on pet food kibbles were evaluated. Using canola oil and dry dog digest as fat and flavor …

Whole Genome Analysis And Molecular Traceability Study Of Salmonella In Fresh Livestock And Poultry Meat, Sheng Song, Han Gao, Li Yan, Kun-Peng Guo, Hai-Yun Zhang, Fang-Bin Wang

Food and Machinery

In order to investigate the contamination status of Sal-monella in fresh pork and fresh chicken, and research its whole genome characteristics and molecular traceability, the laboratory randomly collected 24 fresh pork and 27 fresh chicken from the fresh market in Changsha, were inspected according to “National Food Safety Standard Food microbiological examination: Salmonella” GB 4789.4—2016. The results showed that in 24 randomly selected fresh pork, 20 samples were detected, with the detection rate of 83.3%; in 27 randomly selected fresh chicken, 20 samples were detected, and the detected rate is 74.1%; the total detection rate was 78.4%. The results …

Mitigation Of Salmonella On Food Contact Surfaces By Using Organic Acid Mixtures Containing 2-Hydroxy-4-(Methylthio) Butanoic Acid (Hmtba), Aiswariya Deliephan, Janak Dhakal, Bhadriraju Subramanyam, Charles G. Aldrich

Department of Food Science and Technology: Faculty Publications

Contaminated surfaces can transmit pathogens to food in industrial and domestic food-handling environments. Exposure to pathogens on food contact surfaces may take place via the cross-contamination of pathogens during postprocessing activities. Formaldehyde-based commercial sanitizers in recent years are less commonly being used within food manufacturing facilities due to consumer perception and labeling concerns. There is interest in investigating clean-label, food-safe components for use on food contact surfaces to mitigate contamination from pathogenic bacteria, including Salmonella. In this study, the antimicrobial effects of two types of organic acid mixtures containing 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), Activate DA™ and Activate US WD-MAX™, …

Mitigation Of Salmonella On Food Contact Surfaces By Using Organic Acid Mixtures Containing 2-Hydroxy-4-(Methylthio) Butanoic Acid (Hmtba), Aiswariya Deliephan, Janak Dhakal, Bhadriraju Subramanyam, Charles G. Aldrich

Department of Food Science and Technology: Faculty Publications

Contaminated surfaces can transmit pathogens to food in industrial and domestic food-handling environments. Exposure to pathogens on food contact surfaces may take place via the cross-contamination of pathogens during postprocessing activities. Formaldehyde-based commercial sanitizers in recent years are less commonly being used within food manufacturing facilities due to consumer perception and labeling concerns. There is interest in investigating clean-label, food-safe components for use on food contact surfaces to mitigate contamination from pathogenic bacteria, including Salmonella. In this study, the antimicrobial effects of two types of organic acid mixtures containing 2-hydroxy-4-(methylthio) butanoic acid (HMTBa), Activate DA™ and Activate US WDMAX …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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

Survival, Regrowth And Morphotype Formation Of Salmonella Strains After Exposure To High Or Low Concentrations Of First Generation Qac In Water, Grace Umutesi

Theses and Dissertations

This study determines the differences in survival of eight Salmonella strains concentration of BAC in water, followed by regrowth in high and low nutrition conditions containing sublethal concentration of BAC. Our results show strain difference in survival, persistence of Salmonella in BAC at different concentrations. All eight strains of Salmonella were non-recoverable when exposed to 40 to 48 µg/ml BAC for 1h in water. When exposed to 24 µg/ml of BAC for 1 h in water, S. Typhimurium ATCC 14028 and S. Heidelberg ATCC 8326 cells were non-detectable from the initial 7 log CFU/ml. S. Blockley 7175, S. Virchow 7207, …

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 …

Thermal Inactivation Kinetics Of Salmonella In Milk Powder As Impacted By Water Activity And Powder Type, Erika Litta Kadas

Graduate Theses and Dissertations

Historically, low-water activity (aw) foods (aw <0.65) were considered to be microbiologically safe for consumption. However, these foods have been implicated in outbreaks of pathogens such as Salmonella enterica, at a frequency that surely challenges this assumption of safety. Although usually implicated in outbreaks involving poultry and egg products, Salmonella spp. have frequently been the culprit in several outbreaks and recalls associated with low-water activity foods (LWAF) due to contamination resulting from the environment, animals, or even the employees during pre-or post-processing. One such LWAF that has been associated with Salmonella spp. outbreaks is milk powder. Milk powders are used in a variety of products ranging from infant formula to confectionary goods. With their widespread use, improving their safety is imperative. A key step in improving their safety is to thoroughly investigate preventive controls related to milk powder processing. The Food Safety Modernization Act (FSMA) established the Preventive Controls for Human Foods Rule, which mandates that processors design and establish a food safety plan outlining any potential hazards and the steps they will take to ensure those hazards do not compromise the safety of the product. Presently, the dairy industry does not have an established kill-step for milk powders post-spray drying. Spray drying may reduce some microbial populations, however, desiccation(e.g., spray drying) is not considered a kill-step. The work outlined in this thesis aims to assist our dairy industry partners in establishing their own thermal process for milk powders post-spray drying. Moisture sorption isotherms of two milk powders (nonfat dry milk: NFDM and a milk protein concentrate with 85% protein content: MPC-85) were determined and showcased that the temperatures at which the isotherms were determined (23, 40, or 60°C) significantly affected both the adsorption and desorption isotherms (p<0.0001) for each powder. Secondly, the thermal inactivation kinetics of Salmonella spp. in both powders were evaluated at two different water activities (0.20 and 0.30) and three temperatures (75, 80, and 85°C) to determine the effect of water activity on the thermal resistance of a cocktail of Salmonella spp. The D-values of Salmonella were heavily influenced by the thermal treatment temperature (p< 0.0001), but not the water activity (p >0.05). The overall findings contained within this thesis provide valuable information about the thermal inactivation kinetics of Salmonella spp. to our partners in the dairy industry so that they may implement an appropriate thermal process for their milk powders.

Effectiveness Of Selected Pre-Enrichment Broths For The Detection Of Salmonella Spp. In Meat Analogs, Georgia L. Sampson, Shannon B. Ruelle, Lieuchi Phan, Donna Williams-Hill, Rosalee S. Hellberg

Food Science Faculty Articles and Research

With the increasing variety of meat analog products, it is important to verify that the methods used for Salmonella detection are effective. The objective of this study was to compare the efficacy of three pre-enrichment broths for the detection of Salmonella in meat analog burgers: the currently used Bacteriological Analytical Manual (BAM) broth (lactose broth with Triton X-100, LB-T), universal pre-enrichment (UP) broth, and buffered peptone water (BPW). Five different meat analog products (coded A-E) were inoculated with Salmonella serotypes (S. Enteritidis or S. Agona) following the Food and Drug Administration Method Modification and Method Extension Criteria for Existing …

Growth Of Foodborne Pathogens Listeria And Salmonella And Spore-Forming Paenibacillus In Commercial Plant-Based Milk Alternatives, Klaudia Bartula

ORBioM (Open Research BioSciences Meeting)

An increase in vegan diet preference, lactose intolerance, calorie concern and environmental awareness has led to a rise in the popularity of plant-based alternatives to bovine milk. Non-dairy products are a fast-growing food industry sector; however, there are still gaps in understanding how the known bacterial food contaminants behave in plant-based beverages. The present study is the first to compare the growth of food-pathogens Listeria monocytogenes and Salmonella enterica and an industrial milk product isolate, spore-forming Paenibacillus, in commercially available ultrahigh temperature processed (UHT) bovine milk and plant-based milk alternatives (coconut, almond, cashew). Beverage samples were inoculated with a strain …

To The Window, To The Wall: Improving Environmental Monitoring Protocols, Sarah Jones

Graduate Theses and Dissertations

Detecting microorganisms on environmental surfaces via an environmental monitoring (EM) program is part of a preventive food safety culture. Environmental monitoring should 1) verify that food safety plans are reducing cross-contamination risk from surfaces to food, 2) pinpoint microbial niches, and 3) prevent the transmission of pathogens. Environmental monitoring programs utilize EM tools, such as sponges, to sample food contact and non-food contact surfaces. However, EM tool selection is determined by the individual food firm. This dissertation evaluated and characterized factors influencing EM program effectiveness in the food industry. Specifically, this dissertation focuses on the release of microorganisms from EM …

Inactivation Of Salmonella In Black Peppercorn By Fluidization With Hydrogen Peroxide Vapor, Edel Summers

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

The purpose of the present study was to assess the effectiveness of hydrogen peroxide vapor (HPV) at inactivating Salmonella inoculated in whole black pepper when used as fluidizing gas media. HPV treatment was conducted at two different temperatures (45°C and 60°C) and two dwell times (30 min and 60 min). Microbial reduction and residual hydrogen peroxide were measured at three storage times: 0 h (immediately after treatment), 24 h and 48 h post-treatment. The effect of HPV on the quality of whole black peppercorn was evaluated 48 h post-treatment based on changes in piperine content, total phenolics, antioxidant activity, total …