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Characterization And Evaluation Of The Probiotic Properties Of The Sporeforming Bacteria, Bacillus Coagulans Unique Is-2, Amy Garrison May 2019

Characterization And Evaluation Of The Probiotic Properties Of The Sporeforming Bacteria, Bacillus Coagulans Unique Is-2, Amy Garrison

Dissertations, Theses, & Student Research in Food Science and Technology

Probiotics are live organisms, that when consumed in adequate amounts, confer a health benefit to the host. To achieve probiotic status, each potential strain’s functional properties and their safety to the consumer must be comprehensively evaluated. Probiotic effects have been observed to be strain specific, therefore each new strain of interest must be characterized according to their phenotypic and genetic characteristics. There is a list of characteristics that potential probiotic strains should have to be considered as a probiotic. Potential probiotic strains should be evaluated for their acid and bile salt resistance, antimicrobial activity and adherence and colonization to ...


A Risk-Based Approach To Evaluate The Impact Of Interventions At Reducing The Risk Of Foodborne Illness Associated With Wheat-Based Products, Luis Sabillon Oct 2018

A Risk-Based Approach To Evaluate The Impact Of Interventions At Reducing The Risk Of Foodborne Illness Associated With Wheat-Based Products, Luis Sabillon

Dissertations, Theses, & Student Research in Food Science and Technology

Pathogens are emerging on previously unrecognized food vehicles, such as wheat flour, which is a widely consumed commodity. Despite its low water activity, wheat-based ingredients and products have been implicated in several foodborne outbreaks over the last few years, resulting not only in the recall of food products but also in consumer illnesses. As a raw agricultural commodity, wheat is exposed to naturally occurring microbiological contamination that may compromise the overall safety of flour and other derived products. To address the increased concern regarding the safety of wheat-based foods, the objectives of the present research study were designed to develop ...


Implementation Of Iso/Iec Practices In Small And Academic Laboratories, Eric Layne Oliver Aug 2018

Implementation Of Iso/Iec Practices In Small And Academic Laboratories, Eric Layne Oliver

Dissertations, Theses, & Student Research in Food Science and Technology

Food Manufacturers are facing challenging times due to regulations such as the Food Safety Modernization Act (FSMA) requiring them to provide evidence they are producing safe foods. Food testing laboratories aid in the mitigation of food safety issues providing evidence that a manufacturers food safety system is acceptable. To perform these activities laboratories are required to adhere to certain standards such as ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories. However, implementation of ISO/IEC 17025 practices is challenging, especially for small and academic laboratories, due to lack of available guidance. A long-term goal of ...


Thermal Inactivation Kinetics Of Salmonella Enterica And Enterococcus Faecium In Ground Black Pepper, Sabrina Vasquez Aug 2018

Thermal Inactivation Kinetics Of Salmonella Enterica And Enterococcus Faecium In Ground Black Pepper, Sabrina Vasquez

Dissertations, Theses, & Student Research in Food Science and Technology

Food safety concerns of low-awfoods have boosted, given the increased number of foodborne illnesses related to these products. Black pepper, among other spices, has been implicated in several outbreaks and recalls in recent years.Salmonella entericahas been identified as the causing agent of outbreaks of contaminated spices. Therefore, increased efforts should be conducted to ensure food safety of spices, including black pepper. Food Safety Modernization Act (FSMA) demands all food processing facilities to conduct proper validations of the decontamination technologies applied to food products. Complete thermal process validations require a deep understanding of the thermal inactivation kinetics ...


Effect Of Gallic And Ferulic Acids On Oxidative Phosphorylation On Candida Albicans (A72 And Sc5314) During The Yeast-To-Hyphae Transition, Rehab Aldahash May 2018

Effect Of Gallic And Ferulic Acids On Oxidative Phosphorylation On Candida Albicans (A72 And Sc5314) During The Yeast-To-Hyphae Transition, Rehab Aldahash

Dissertations, Theses, & Student Research in Food Science and Technology

Candida albicans is a dormant commensal in the mucosa of healthy individuals but can become an opportunistic pathogen when the host microflora is compromised. It has been reported as the most common cause of fungal infection among hospitalized U.S. patients, with elevated mortality rate. Candida species have been reported as resistant to antifungal drugs that increase the application of novel strategies to treat this infection. Among the natural compounds that have most gained attention as potential agents against fungi are phenolic compounds against fungi. C. albicans has the ability to switch phenotype from yeast-to-hyphae cells, with hyphae being the ...


Radiofrequency Processing For Inactivation Of Salmonella Spp. And Enterococcus Faecium Nrrl B-2354 In Whole Black Peppercorn And Ground Black Pepper, Xinyao Wei Dec 2017

Radiofrequency Processing For Inactivation Of Salmonella Spp. And Enterococcus Faecium Nrrl B-2354 In Whole Black Peppercorn And Ground Black Pepper, Xinyao Wei

Dissertations, Theses, & Student Research in Food Science and Technology

Black pepper has been implicated in several foodborne illness outbreaks and food product recalls due to Salmonella contamination. Conventional decontamination methods for black pepper are challenged by harmful residues or quality deterioration. Radiofrequency (RF) heating reduces the come-up time which allows to design a high-temperature short-time processing to inactivate Salmonella with minimal deterioration in product quality. The objectives of this study were to investigate RF heating for inactivation of Salmonella in whole black peppercorn and ground black pepper samples, evaluate Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella, and assess quality deterioration during RF heating of whole black peppercorn ...


Modeling The Survival Of Salmonella In Soy Sauce-Based Products Stored At Two Different Temperatures, Ana Cristina Arciniega Castillo Aug 2017

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

Dissertations, Theses, & Student Research in Food Science and Technology

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

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


Validation Of Extrusion Processing For The Safety Of Low-Moisture Foods, Tushar Verma Aug 2017

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

Dissertations, Theses, & Student Research in Food Science and Technology

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


Risk Assessment And Research Synthesis Methodologies In Food Safety: Two Effective Tools To Provide Scientific Evidence Into The Decision Making Process., Juan E. Ortuzar Dec 2016

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

Dissertations, Theses, & Student Research in Food Science and Technology

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


From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza Jul 2016

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza

Dissertations, Theses, & Student Research in Food Science and Technology

This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and ...


Studies Of Debaryomyces Hansenii Killer Toxin And Its Effect On Pathogenic Bloodstream Candida Isolates, Rhaisa A. Crespo Ramírez Apr 2016

Studies Of Debaryomyces Hansenii Killer Toxin And Its Effect On Pathogenic Bloodstream Candida Isolates, Rhaisa A. Crespo Ramírez

Dissertations, Theses, & Student Research in Food Science and Technology

Candida species are normal commensal organisms found in the skin, mouth, and gastrointestinal and genitourinary tracts of humans. Candida albicans is a normal component of the gut flora, and the oral and genital cavities. However, this organism is an opportunistic pathogen and it is one of the most frequently isolated species from patients with nosocomial fungal infections. Candida infections have grown in recent years due to antimycotics resistance and the extensive use of antibiotics. This has pushed scientists to look for alternative therapeutic agents to treat fungal infections.

Yeasts can produce toxic proteins called “mycocins” or “killer toxins” that can ...


Comparative Study Of The D-Values Of Salmonella Spp. And Enterococcus Faecium In Wheat Flour, Didier Dodier Dec 2015

Comparative Study Of The D-Values Of Salmonella Spp. And Enterococcus Faecium In Wheat Flour, Didier Dodier

Dissertations, Theses, & Student Research in Food Science and Technology

Low-moisture foods contaminated with Salmonella spp. have been implicated in several foodborne illness outbreaks in the United States. The food industry has to incorporate preventive control in their process and validate thermal processes to assure food safety. The thermal destruction of Enterococcus faecium ATTC 8459 and Salmonella spp. was determined at 3 water activity levels (0.11, 0.18 and 0.33) at 80ºC, 85ºC and 90ºC. Aerobic plates counts petrifilms were used as non-selective medium for both bacteria, Enterobacteriaceae petrifilms were used as selective medium for Salmonella spp., and peptone water modified with sodium azide as a selective medium ...


Inactivation Of Escherichia Coli O157:H7 And Shiga Toxin Producing E. Coli (Stec) Throughout Beef Summer Sausage Production And The Use Of High Pressure Processing As An Alternative Intervention To Thermal Processing, Eric L. Oliver Dec 2015

Inactivation Of Escherichia Coli O157:H7 And Shiga Toxin Producing E. Coli (Stec) Throughout Beef Summer Sausage Production And The Use Of High Pressure Processing As An Alternative Intervention To Thermal Processing, Eric L. Oliver

Dissertations, Theses, & Student Research in Food Science and Technology

Escherichia coli O157:H7 and six additional serogroups of Shiga Toxin-producing E. coli (STEC-7) have been implicated in foodborne illness outbreaks related to fermented sausage products and are considered adulterants by the USDA-FSIS. The objective of this study was to evaluate high pressure processing (HPP) as an alternative to thermal treatment to reduce STEC-7 meeting the USDA-FSIS performance standards (5.0-log reduction). A rifampicin-resistant, non-pathogenic E. coli (surrogate) cocktail, was used in manufacturing testing. Sausages were fermented at ~42.2°C, slowly increased to 54.4°C internal temperature, cold showered, and chilled for 6 hours. Sampling occurred post-fermentation (PF ...


Efficacy Of Galactooliosaccharide (Gos) And/Or Rhamnose-Based Synbiotics In Enhancing Ecological Performance Of Lactobacillus Reuteri In The Human Gut And Characterization Of Its Gos Metabolic System, Monchaya Rattanaprasert Dec 2015

Efficacy Of Galactooliosaccharide (Gos) And/Or Rhamnose-Based Synbiotics In Enhancing Ecological Performance Of Lactobacillus Reuteri In The Human Gut And Characterization Of Its Gos Metabolic System, Monchaya Rattanaprasert

Dissertations, Theses, & Student Research in Food Science and Technology

Probiotic L. reuteri has potential to produce antimicrobial compounds and secrete immunosuppressive factors. These metabolic attributes could benefit the human host by providing colonization resistance (competitive and metabolic exclusion) against enteropathogens and mitigating inflammation. As metabolically active cells are fundamental to such probiotic properties, synbiotic approaches that supply L. reuteri with a source(s) of carbon, energy, and/or external electron acceptor for cell growth in the gut environment could therefore prompt the probiotic to engage in beneficial activities. In this study, the efficacy of GOS and/or rhamnose-based synbiotic approaches in promoting colonization persistence and metabolic activity of L ...


Characterization And Investigation Of Fungi Inhabiting The Gastrointestinal Tract Of Healthy And Diseased Humans, Mallory J. Suhr May 2015

Characterization And Investigation Of Fungi Inhabiting The Gastrointestinal Tract Of Healthy And Diseased Humans, Mallory J. Suhr

Dissertations, Theses, & Student Research in Food Science and Technology

Gastrointestinal microbiome studies have failed to include fungi in total community analyses. As a result, their diversity and function in the gut is poorly understood. Recent work has begun to uncover the role intestinal fungi play in diet, immune system development, interactions with other microorganisms in the gut, and pathogenesis of diseases. Advances in sequencing technologies allow for the ability to profile the fungal gut microbiome (“mycobiome”) in healthy and diseased states. This thesis explores the mycobiome in 1) healthy humans with a vegetarian diet and 2) pediatric small bowel transplant recipients that develop fungal bloodstream infections.

The gut mycobiome ...


The Influence Of The Bovine Fecal Microbiota On The Shedding Of Shiga Toxin-Producing Escherichia Coli (Stec) By Beef Cattle, Nirosh D. Aluthge May 2015

The Influence Of The Bovine Fecal Microbiota On The Shedding Of Shiga Toxin-Producing Escherichia Coli (Stec) By Beef Cattle, Nirosh D. Aluthge

Dissertations, Theses, & Student Research in Food Science and Technology

During the past three decades, Shiga toxin-producing E.coli (STEC) have emerged as an important food safety concern. Although initially E. coli O157 was the main focus, recent outbreaks and resulting investigations have shown that certain non-O157 STEC are as much a threat to food safety as their O157 counterparts. To the beef industry, STEC have been of particular concern due to the frequent association of beef and beef products as vehicles of STEC infection. As a result, along with E. coli O157, six non-O157 STEC serogroups (known as the ‘big six’) are now regulated as adulterants in certain raw ...


Viability Of Lactobacillus Acidophilus Dds 1-10 Encapsulated With An Alginate-Starch Matrix, Liya Mo May 2015

Viability Of Lactobacillus Acidophilus Dds 1-10 Encapsulated With An Alginate-Starch Matrix, Liya Mo

Dissertations, Theses, & Student Research in Food Science and Technology

L. acidophilus DDS1-10 was encapsulated using an alginate, potato starch and type 4 resistant starch (RS4) matrix. The wall material was optimized by varying levels of alginate (1.6 to 4.4%), while maintaining potato starch and RS4 ratio fixed at 2, and the total solid content at 5%. Particles were prepared using an emulsion and an extrusion method. Particles obtained from the emulsion method were smaller with a non-uniform distribution in size while those obtained by the extrusion method were bigger and uniform in size. The emulsion method did not seem to offer protection to the probiotic cells against ...


Characterization Of Commercial Probiotics: Antibiotic Resistance, Acid And Bile Resistance, And Prebiotic Utilization, Carmen Lucia Cano Roca Aug 2014

Characterization Of Commercial Probiotics: Antibiotic Resistance, Acid And Bile Resistance, And Prebiotic Utilization, Carmen Lucia Cano Roca

Dissertations, Theses, & Student Research in Food Science and Technology

Probiotics, live microorganisms that beneficially affect the health of their host, must undergo extensive research to ensure they are safe for consumption and possess certain functional properties. Antibiotic resistance in probiotics has raised concern due to the possibility of its transfer to pathogens. Acid and bile tolerance ensures that organisms will survive passage into the intestines. Prebiotic utilization indicates ability to ferment specific carbohydrates for enhanced growth. The objective of this study was to characterize a group of commercial probiotics for their suitability as probiotics.

Nine commercial probiotic strains (7 Lactobacillus, 1 Lactococcus lactis, and 1 Bifidobacterium longum) were evaluated ...


Adherence Inhibition Of Human Pathogens Campylobacter Jejuni And Campylobacter Coli By Non-Digestible Oligosaccharides, Alejandra Ramirez-Hernandez Jul 2014

Adherence Inhibition Of Human Pathogens Campylobacter Jejuni And Campylobacter Coli By Non-Digestible Oligosaccharides, Alejandra Ramirez-Hernandez

Dissertations, Theses, & Student Research in Food Science and Technology

Adherence is the first and one of the most important steps of bacterial pathogenesis. Natural derived components that inhibit the adherence of pathogens to the surface of epithelial cells have received considered interest. The goal of this research was to assess the anti-adherence activity of mannan oligosaccharides (MOS), pectic oligosaccharides (POS) and cranberry high molecular weight component (HMW) against Campylobacter jejuni and Campylobacter coli. First the anti-adherence activity of MOS and their purified fraction (pMOS) was tested against three strains of C. jejuni and two strains of C. coli. Results shown significant reductions in adherence (up to 70%) of all ...


Understanding The Factors Affecting Microbiological Quality Of Wheat Milled Products: From Wheat Fields To Milling Operations, Luis E. Sabillón Galeas Jul 2014

Understanding The Factors Affecting Microbiological Quality Of Wheat Milled Products: From Wheat Fields To Milling Operations, Luis E. Sabillón Galeas

Dissertations, Theses, & Student Research in Food Science and Technology

Although regarded as a low-risk commodity, wheat flour-based mixes have been implicated in several food safety incidents. The present thesis is a compilation of five scientific manuscripts on the effect of weather variation, milling steps and implementation of pre-milling interventions on the microbiological quality and safety of wheat and milled products. The first manuscript is a review of the microbiological quality and safety of wheat-based products. Despite the low water activity, wheat flour may harbor dormant but viable microorganisms, which could lead to safety concerns when flour is used to produce refrigerated dough products. The second manuscript illustrates the effect ...


Non-Digestible Oligosaccharides: Anti-Adherence And Other Biological Properties, Maria I. Quintero-Villegas Jul 2014

Non-Digestible Oligosaccharides: Anti-Adherence And Other Biological Properties, Maria I. Quintero-Villegas

Dissertations, Theses, & Student Research in Food Science and Technology

Bacterial adherence is the first and one of the most important steps in bacterial pathogenesis. Adherence to host cell surfaces requires that the bacteria recognize specific receptors in the surface of epithelial cells. Therefore, agents that act as molecular decoys to interfere with adherence could be useful prophylactic treatments to prevent or mitigate the onset of infections. The goal of this research was to assess the ability of several food grade non-digestible oligosaccharides (NDOs) to act as molecular decoys and prevent bacterial adherence in vitro as well as in vivo. First, the antiadherence effect of specific species chitooligosaccharides (CHOS) at ...


Tracking Heat-Resistant, Sporeforming Bacteria In The Milk Chain: A Farm To Table Approach, Maricarmen Estrada Anzueto Apr 2014

Tracking Heat-Resistant, Sporeforming Bacteria In The Milk Chain: A Farm To Table Approach, Maricarmen Estrada Anzueto

Dissertations, Theses, & Student Research in Food Science and Technology

Sporeforming bacteria (such as Bacillus and Paenibacillus spp.) can survive pasteurization conditions (Collins, 1981) and grow in pasteurized fluid milk during refrigerated storage (Huck et al., 2008; Ivy et al., 2012), causing fluid milk spoilage and limiting the further extension of fluid milk’s shelf life (Fromm and Boor, 2004; Durak et al., 2006). Moreover, Bacillus and related genera have been found in raw milk, pasteurized milk and environmental samples from dairy farms, indicating that these organisms are ubiquitous in nature and can enter the milk chain from different sources (Huck et al., 2007b; Huck et al., 2008; Ranieri and ...


Debaryomyces Hansenii: A Foodborne Yeast That Produces Anti-Candida Killer Toxin, Nabaraj Banjara Apr 2014

Debaryomyces Hansenii: A Foodborne Yeast That Produces Anti-Candida Killer Toxin, Nabaraj Banjara

Dissertations, Theses, & Student Research in Food Science and Technology

Candida yeasts are commensal members of the gastrointestinal, mucosal, oral and vaginal microbiota. Candida albicans and C. tropicalis can be found as a part of the normal human commensal flora, especially in all sections of the gastrointestinal tract. However, when the host defense system and microbiota are disturbed, Candida can become pathogenic and cause severe infection or candidiasis. Antifungal drugs used to treat candidiasis have been shown to result in treatment failures due to drug toxicity and/or development of resistance during long term antifungal therapy and, in recent years, the incidence of Candida infections has increased dramatically due to ...


Characterization Of The Gut Microbiota And Colitogenic Bacterial Species In Core 1 O-Glycans Deficient Mice, Maria E. Perez-Munoz Jul 2013

Characterization Of The Gut Microbiota And Colitogenic Bacterial Species In Core 1 O-Glycans Deficient Mice, Maria E. Perez-Munoz

Dissertations, Theses, & Student Research in Food Science and Technology

Mucus is one important component of the intestinal mucosal barrier, and loss of its functionality is associated with colitis in humans and mice. Mice deficient in core 1 O-glycans (TM-IEC C1galt1-/-) display a thinner mucus layer upon mutation of the glycosyltransferase enzyme (C1GALT1) responsible for core 1 O-glycans attachment, thus constituting an experimental model for human Ulcerative Colitis (UC). Under conventional conditions, these mice experience spontaneous inflammation of the colon. However, the exact role of the microbiota in colitis development in these mice has not been systematically investigated.

Aimed to gain insights into the role of the microbiota ...


Evidence Of Transmission Of Escherichia Coli O157:H7 To The Tissues Or Phyllo-Plane Of Wheat, From Contaminated Soil, Seeds Or Water, Bismarck Antonio Martinez Nov 2012

Evidence Of Transmission Of Escherichia Coli O157:H7 To The Tissues Or Phyllo-Plane Of Wheat, From Contaminated Soil, Seeds Or Water, Bismarck Antonio Martinez

Dissertations, Theses, & Student Research in Food Science and Technology

Escherichia coli O157:H7 is a human pathogen that can cause a wide spectrum of disease symptoms, such as bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Escherichia coli O157:H7 illness are mainly associated with undercooked beef; however, in recent years outbreaks have been linked to fresh produce such as spinach, lettuce, and sprouts. In 2009, flour was implicated as a contamination source in the consumption of raw cookie dough resulting in 77 illness-cases. The objective of this research was to determine the possible route of transmission of E. coli O157:H7 into the phyllo-plane of wheat using ...


Analysis Of Microbial Diversity By Amplicon Pyrosequencing, Ryan Legge Aug 2012

Analysis Of Microbial Diversity By Amplicon Pyrosequencing, Ryan Legge

Dissertations, Theses, & Student Research in Food Science and Technology

Microorganisms numerically dominate terrestrial biodiversity, and play important biochemical and geochemical roles in the environments they inhabit. To understand structure and function of complex ecosystems, it is essential to identify primary drivers of microbial diversity and community structure. Historically, the study of microbial ecology was reductive, limited to microbes able to be cultured and enumerated. Microbes meeting this criterion were thought to comprise the dominating members of the environments they were isolated from, however, estimates suggesting up to 99% of the endogenous species are uncultivable with existing methodologies; a concept that reflects experimental failure, rather than a verifiable conclusion. Therefore ...


Validation Of Thermal Processing To Control Salmonella Spp. And Clostridium Perfringens During Prime Rib Preparation From Intact And Non-Intact Meat, Maria A. Calle May 2012

Validation Of Thermal Processing To Control Salmonella Spp. And Clostridium Perfringens During Prime Rib Preparation From Intact And Non-Intact Meat, Maria A. Calle

Dissertations, Theses, & Student Research in Food Science and Technology

Beef prime rib is a delicacy cooked at low temperatures for long period and extended hot holding prior to consumption. Due to the potential survival and outgrowth of foodborne pathogens, this process may pose a public health risk. Considering an increase in the availability of non-intact beef, the microbial safety of the preparation of prime rib from intact and mechanically tenderized beef was evaluated.

In the first study, lethality of the prime rib (from intact and non-intact, blade tenderized beef) cooking process to Salmonella spp. was evaluated. Boneless beef rib eye was surface inoculated with a five-strain cocktail of Salmonella ...


Studies On The Adherence Properties Of Plant Lectins And Bacterial Adhesins And Their Inhibition By Prebiotic Oligosaccharides And Bovine Colostrum Fractions, Maria X. Maldonado-Gomez Nov 2011

Studies On The Adherence Properties Of Plant Lectins And Bacterial Adhesins And Their Inhibition By Prebiotic Oligosaccharides And Bovine Colostrum Fractions, Maria X. Maldonado-Gomez

Dissertations, Theses, & Student Research in Food Science and Technology

To initiate colonization and infection, most microbial pathogens must first recognize and adhere to cells in the host tissues. Adherence inhibition, therefore, can be used as a strategy for preventing infectious disease. In this research, we developed a simplified model using plant lectins and HEp-2 tissue culture cells to simulate bacterial adhesins-receptors interactions. The effect of lectin ligands and two prebiotic carbohydrates, galactooligosaccharide (GOS) and polydextrose (PDX) was measured with this approach. Lectins that were able to bind to the target cells were inhibited in the presence of the cognate ligands and at least one of the prebiotic carbohydrates. The ...


Effect Of Sodium Nitrite, Sodium Erythorbate And Organic Acid Salts On Germination And Outgrowth Of Clostridium Perfringens Spores In Ham During Abusive Cooling, Mauricio A. Redondo Sep 2011

Effect Of Sodium Nitrite, Sodium Erythorbate And Organic Acid Salts On Germination And Outgrowth Of Clostridium Perfringens Spores In Ham During Abusive Cooling, Mauricio A. Redondo

Dissertations, Theses, & Student Research in Food Science and Technology

The effect of sodium nitrite (NaNO2), sodium erythorbate, sodium chloride (NaCl) and organic acid salts (potassium lactate and sodium diacetate) on C. perfringens spore germination and outgrowth in ham was evaluated. The research was divided in two parts. The first experiment consisted of potential C. perfringens spore germination and outgrowth in ham containing combinations of NaNO2 (0, 50, 100, 150 or 200 ppm) and sodium erythorbate (0 or 557 ppm) during cooling. This experiment included the evaluation of residual nitrite levels as affected by temperature (heat shock at 75°C for 20 min and subsequent cooling from 54 ...


The Bifidogenicity Of The Prebiotic Galactooligosaccharides, Lauren M. G. Davis Dec 2010

The Bifidogenicity Of The Prebiotic Galactooligosaccharides, Lauren M. G. Davis

Dissertations, Theses, & Student Research in Food Science and Technology

The goal of this research was to determine the effect of different doses of galactooligosaccharide (GOS) on the fecal microbiota of healthy adults, with a focus on bifidobacteria. The study was designed as a single-blinded study, with eighteen subjects consuming GOS-containing chocolate chews at four increasing dosage levels; 0, 2.5, 5.0, and 10.0 g. Subjects consumed each dose for 3 weeks, with a two-week baseline period preceding the study and a two-week washout period at the end. Cultural methods were used for bifidobacteria, Bacteroides, enterobacteria, enterococci, lactobacilli, and total anaerobes; culture-independent methods included denaturing gradient gel electrophoresis ...