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Plant Protein-Based Nanocomposite Materials: Modification Of Layered Nanoclay By Surface Coating And Enhanced Interactions By Enzymatic And Chemical Cross-Linking, Minfeng Jin May 2012

Plant Protein-Based Nanocomposite Materials: Modification Of Layered Nanoclay By Surface Coating And Enhanced Interactions By Enzymatic And Chemical Cross-Linking, Minfeng Jin

Doctoral Dissertations

Highly intercalated or exfoliated nanoclay montmorillonite (MMT) has promises to improve mechanical and barrier properties of nanocomposite materials that may be further improved by strengthening interactions between matrix polymers and nanofillers. In this work, water-soluble proteins extracted from hominy feed and soy flour were utilized to modify the structures of MMT layers by surface-coating. Following coating at 60 °C using different MMT:protein mass ratios (49:1-2:1) and pH (2.0-10.0), the nanoclay was triple-washed for zeta potential analysis and lyophilized for X-ray diffraction and Fourier transform infrared spectroscopy analyses. Results showed that protein adsorption on MMT occurred ...


Nano-Dispersing Lipophilic Antimicrobials For Improved Food Safety, Bhavini Dipak Shah Dec 2011

Nano-Dispersing Lipophilic Antimicrobials For Improved Food Safety, Bhavini Dipak Shah

Doctoral Dissertations

Naturally occurring food antimicrobials such as plant essential oils are receiving tremendous interest as intervention systems to enhance microbiological safety and quality. Poor water solubility of essential oils makes it difficult to incorporate them in foods, impacting visual appearance, antimicrobial effectiveness, and possibly organoleptic properties. Engineered nanoscale delivery systems can principally solve these challenges, but those based on low-cost food ingredients and inexpensive and scalable processes are currently scarce. This dissertation presents a simple and scalable two-step technology to prepare nano-delivery systems. The first encapsulation step, based on emulsion-evaporation, involves preparing emulsions composed of an oil phase with thymol or ...


Antimicrobial Activity Of Aqueous Yerba Mate Extracts, Kellie Parks Burris May 2011

Antimicrobial Activity Of Aqueous Yerba Mate Extracts, Kellie Parks Burris

Doctoral Dissertations

Ilex paraguariensis, is used in the preparation of a widely popular tea beverage (Yerba Mate) mainly produced and consumed in the countries of Uruguay, Paraguay, Argentina and Brazil. Dialyzed aqueous extracts were screened for antimicrobial activity against Escherichia coli O157:H7, Staphylococcus aureus, methicillin-resistant S. aureus and S. pseudintermedius, and Pseudomonas syringae pv. tomato.

Using a concentrated extract, S. aureus was found to be the more sensitive to extracts than E. coli O157:H7. Minimum inhibitory concentration (MIC) was defined as the lowest concentration of extract tested that did not allow bacterial growth (inhibition) above the original inoculums of approximately ...


Novel Delivery Systems Of Nisin To Enhance Long-Term Efficacy Against Foodborne Pathogen Listeria Monocytogenes, Dan Xiao Dec 2010

Novel Delivery Systems Of Nisin To Enhance Long-Term Efficacy Against Foodborne Pathogen Listeria Monocytogenes, Dan Xiao

Doctoral Dissertations

Novel intervention strategies such as food grade antimicrobials are used to enhance food safety. Nisin is a widely used naturally occurring antimicrobial effective against many pathogenic and spoilage microorganisms. However, its antimicrobial efficacy in food matrices is much reduced because of interactions with food components. Novel delivery systems may overcome this problem by protecting nisin in capsules and releasing it in a controlled manner. The overall goal of this research was to develop delivery systems of nisin to improve its long-term antimicrobial effectiveness. The first objective was to develop a low-cost method to extract nisin from a commercial preparation containing ...


The Casein Micelle As An Encapsulation System For Triclosan: Methods Of Micelle Dissociation, Encapsulation, Release, And In Vitro Delivery, Adrienne L. Roach Dec 2009

The Casein Micelle As An Encapsulation System For Triclosan: Methods Of Micelle Dissociation, Encapsulation, Release, And In Vitro Delivery, Adrienne L. Roach

Doctoral Dissertations

This dissertation reports on the use of the casein micelle as an encapsulation and potential delivery system for a low molecular weight hydrophobic compound, triclosan. The ability of the casein micelle to serve in this capacity was tested in a series of experiments investigating: 1) micelle dissociation to expose hydrophobic binding sites of interaction, 2) encapsulation of triclosan, 3) the release of triclosan under various conditions, and 4) the intercellular delivery of triclosan to human liver cells in vitro for the inactivation of a malaria-causing parasite. Casein micelle dissociation and reassociaiton was achieved through high pressure homogenization and solvent-mediated pressure-induced ...


Characterization And Performance Improvement Of Chitosan Films As Affected By Preparation Method, Synthetic Polymers, And Blend Ratios, Jiajie Li Aug 2008

Characterization And Performance Improvement Of Chitosan Films As Affected By Preparation Method, Synthetic Polymers, And Blend Ratios, Jiajie Li

Doctoral Dissertations

Chitosan films prepared with addition of other polymers have been widely studied for their modified properties. In this dissertation, poly (ethylene oxide) (PEO) and poly (N-vinyl-2- pyrrolidone) (PVP) were blended with chitosan. The objectives of the study were (1) to investigate the the effects of film thickness, blend ratios, and preparation methods on the physical, and mechanical properties and functional performance of chitosan/PEO films, and (2) to compare characteristics and functional properties of chitosan/PVP and chitosan/PEO films.

The results demonstrated that regular cast chitosan/PEO films have altered properties than films produced from either polymer alone. Regardless ...


Analysis And Application Of Key Modeling Concepts Utilized In Predictive Microbiology For Food Processing, Darryl G. Black May 2008

Analysis And Application Of Key Modeling Concepts Utilized In Predictive Microbiology For Food Processing, Darryl G. Black

Doctoral Dissertations

The use of modeling techniques for safety and risk prediction in the food supply is a common practice. Factors affecting microbial heat resistance include those inherent to the organism, environmental conditions and the intrinsic properties of the heating menstruum. Varying physiological states of microorganisms could affect the measured response and add uncertainty to results from predictive models. Inactivation tests were performed using Escherichia coli strain K12 and E. coli O157:H7 for various growth conditions: traditionally or statically grown cells, chemostat‐grown cells, and chemostatgrown cells with buffered feed media. Heating menstruum was non‐buffered 0.1% peptone, 0.1 ...


Enterobacter Sakazakii Growth Profile And Tolerance To Chlorine Sanitizers, Diana Carolina Naar Cifuentes May 2008

Enterobacter Sakazakii Growth Profile And Tolerance To Chlorine Sanitizers, Diana Carolina Naar Cifuentes

Doctoral Dissertations

Enterobacter sakazakii is considered an emerging opportunistic pathogen associated with sporadic life-threatening bacterial infections in neonates linked to the compsumption of contaminated infant formula [Stoll et al., 2004]. In 2001 a neonate fatal infection associated with the presence of E. sakazakii in infant formula occurred in the neonatal intensive care unit (NICU) of the University of Tennessee Hospital [Himelright et al., 2002], as a result of this outbreak, the hospital made several policy changes and requested the Food Safety Center of Excellence of University of Tennessee to analyze the growth pattern of this microorganism at the conditions maintained in the ...


The Stability Of Carotenogenic Food Colorants And Strategies To Prolong The Shelf Life In Process Cheese Spread, Ann Marie Doneski Craig Dec 2007

The Stability Of Carotenogenic Food Colorants And Strategies To Prolong The Shelf Life In Process Cheese Spread, Ann Marie Doneski Craig

Doctoral Dissertations

Food quality is often times measured by the way one perceives the food, particularly with respect to color and texture. Color quality often pre-determines expectation making it an important parameter to understand. The same can be said for textural properties of food. Maintaining color and texture are just two ways in which the shelf-life of food can be measured. One particular product that has experienced problems in this area is processed cheese spread in which the US military uses as part of the Meal, Ready-to-Eat (MRE) rations. The cheese spread is one of the most highly accepted products in the ...


Gene Expression Analysis Of Escherichia Coli O157:H7 At 10 And 37°C And Under Acidic Conditions Using High Density Oligonucleotide Microarrays, Kristina K. Carter Dec 2007

Gene Expression Analysis Of Escherichia Coli O157:H7 At 10 And 37°C And Under Acidic Conditions Using High Density Oligonucleotide Microarrays, Kristina K. Carter

Doctoral Dissertations

This purpose of this investigation was to use DNA microarrays to study gene expression in E. coli O157:H7 under refrigerated and acidic conditions. Total RNA from E. coli O157:H7 grown to 7 log CFU/mL under control (37 °C, pH 7), refrigerated (10°C, pH 7), acid adapted (37°C, pH 5.5, then lowered to 3.5), and acid shocked (37°C, pH 7, then lowered to 3.5) conditions was extracted using an optimized Qiagen RNeasy procedure. Total RNA was converted to cDNA, labeled, and hybridized onto an Affymetrix GeneChip® E. coli Genome 2.0 Array ...


Sonochemical And Hydrophobic Modification Of Chitin And Chitosan, Tao Wu Dec 2007

Sonochemical And Hydrophobic Modification Of Chitin And Chitosan, Tao Wu

Doctoral Dissertations

Chitin and chitosan are linear polysaccharides consisting of acetyl-glucosamine and glucosamine units with many potential applications in biomedicine, agriculture and food industry. In the food industry, chitosan can be used as antimicrobial agent and to create active packaging to improve food quality and extend shelf life. Commercial applications of chitosan are closely associated with its functional properties and biological activity, which are primarily governed by two structural properties: degree of acetylation (DA) and molecular weight (MW). The overall goal of this study was to develop methods for tailored modification of DA, MW and functionalities of chitosan.

The research was conducted ...


Application Of Solid Phase Micro-Extraction With Gas Chromatography-Mass Spectrometry For The Determination Of Geosmin And 2-Methylisoborneol In Processed Navy Beans (Phaseolus Vulgaris), Coesha Ancoinette Fairley Aug 2007

Application Of Solid Phase Micro-Extraction With Gas Chromatography-Mass Spectrometry For The Determination Of Geosmin And 2-Methylisoborneol In Processed Navy Beans (Phaseolus Vulgaris), Coesha Ancoinette Fairley

Doctoral Dissertations

This investigation was conducted to address the issue of musty bean products. The main objectives of this study were to: (1) identify the source of the musty, off-flavor in processed navy beans, (2) determine and identify the associated off-flavor compounds (geosmin and 2-methylisoborneol (2-MIB)), and (3) isolate the microorganism(s) responsible for production of the compounds.

To confirm the presence of geosmin and 2-MIB in processed baked beans, an automated gas chromatographic method employing solid phase micro-extraction (SPME-GC-MS) was used. Artificially musty baked beans, known musty beans, and raw ingredients (bacon, navy beans, and water) were analyzed. Results of this ...


Development Of A Real-Time Pcr Assay For Detection And Quantification Of Escherichia Coli O157:H7 In Apple Juice, Nancy Rabalais Detrana May 2007

Development Of A Real-Time Pcr Assay For Detection And Quantification Of Escherichia Coli O157:H7 In Apple Juice, Nancy Rabalais Detrana

Doctoral Dissertations

Apple cider/juice contaminated with Escherichia coli O157:H7 has been implicated in several foodborne illness outbreaks, but due to the presence of reaction inhibitors, detection by polymerase chain reaction (PCR) is often difficult. The studies presented in this dissertation were conducted to evaluate techniques to improve detection of E. coli O157:H7 in apple juice using a fluorogenic probe-based real-time PCR assay without prior enrichment. Two commercial DNA extraction and purification procedures, GenEluteTM Bacterial Genomic DNA Kit and PrepMan® Ultra Sample Preparation Reagent, were combined with two real-time PCR chemistries, SYBR® Green I dye and TaqMan® probes for potential ...


Physicochemical Characterization And Antibacterial Potential Of Naturally-Occurring Antimicrobial Polypeptide-Bearing Phospholipid Liposomes Against The Foodborne Pathogens Listeria Monocytogenes And Escherichia Coli O157:H7, Thomas Matthew Taylor Dec 2006

Physicochemical Characterization And Antibacterial Potential Of Naturally-Occurring Antimicrobial Polypeptide-Bearing Phospholipid Liposomes Against The Foodborne Pathogens Listeria Monocytogenes And Escherichia Coli O157:H7, Thomas Matthew Taylor

Doctoral Dissertations

Liposomes are spherical bilayer vesicles formed from dispersion of polar lipids in aqueous solvents and have been studied for their ability to act as drug delivery vehicles by shielding reactive or sensitive compounds prior to release. In the food industry, liposomes have been used to deliver food flavors and nutrients; more recently they have been investigated for their ability to incorporate food antimicrobials.

Thermal stability of liposomes, in the presence and absence of nisin, was evaluated using differential scanning calorimetry (DSC) and low-intensity ultrasonic spectroscopy (US). Observed phase transition temperatures for liposomes measured via DSC and US were in close ...


Potential Development Of Resistance To Food Antimicrobials By Foodborne Pathogens, Lilia Milagros Santiago Santiago May 2006

Potential Development Of Resistance To Food Antimicrobials By Foodborne Pathogens, Lilia Milagros Santiago Santiago

Doctoral Dissertations

The potential for development of resistance of four strains of Listeria monocytogenes (101, 108, 310 and Scott A) and Salmonella Typhimurium DT 104 (2380, 2576, 2582, 2486) to food antimicrobials sodium benzoate (SB), potassium sorbate (PS), sodium diacetate (SD) and sodium lactate (SL) at pH 6.0 was studied. Cells were not subjected to any pre-stress condition. An agar dilution assay was performed to determine susceptibility and adaptation to different and increasing antimicrobial concentrations. A microbroth dilution assay was used to determine tolerance development after two consecutives exposures to same antimicrobial concentrations, and one further exposure to a step higher ...


Antimicrobial Activity And Effect Of Selected Essential Oil Components On Cell Membrane Lipids, Valerie W. Ling Dec 2004

Antimicrobial Activity And Effect Of Selected Essential Oil Components On Cell Membrane Lipids, Valerie W. Ling

Doctoral Dissertations

The objectives of this study were to evaluate the antimicrobial activity of essential oil components (EOC) against Salmonella Typhimurium and Listeria monocytogenes and evaluate changes in bacterial membrane composition by observing changes in the fatty acids of Salmonella associated with exposure and adaptation to (or growth in the presence of) cinnamaldehyde (CIN) and carvacrol (CRV) EOC. Ten EOC were tested for efficacy using the broth microdilution and macrodilution methods. Beta-caryophyllene, limonene, alpha-pinene, and thymol were not lethal to Salmonella and Listeria at 2800mg/L. Dose-response models showed that the most effective EOC against Salmonella were CIN and CRV (50% probability ...


A Multi-State Molecular Epidemiological Survey Of 16 Beef, Dairy, Poultry And Swine Farms To Facilitate Risk Assessment Of Listeria Monocytogenes, David Dean Rasmussen Dec 2004

A Multi-State Molecular Epidemiological Survey Of 16 Beef, Dairy, Poultry And Swine Farms To Facilitate Risk Assessment Of Listeria Monocytogenes, David Dean Rasmussen

Doctoral Dissertations

Listeria monocytogenes s an intracellular pathogen that poses serious risks for immuno-compromised individuals. On the farm risk assessment is needed to reduce exposure of such individuals to this pathogen. Base line epidemiological surveys for this pathogen are needed to identify common ecological reservoirs and sources. A 21 month survey of 4 animal farm types for L. monocytogenes in five different states was conducted to determine the level of occurrence in various environments. An overall occurrence of 1.4% (20/1432 samples) for L. monocytogenes was observed in this 21 month survey. Each sample type (soil, bedding/litter, feed/grass and ...


Quality Control Standards For Cooked Frozen Green Beans Held Heated For Varying Holding Times, Anna Mae Brenner Dec 1975

Quality Control Standards For Cooked Frozen Green Beans Held Heated For Varying Holding Times, Anna Mae Brenner

Doctoral Dissertations

Objective quality control standards for prepared food, held heated for varying periods of time were studied. Frozen Grade A whole stringless Peco and Slender White string green beans grown, blast frozen, and packaged in Tennessee were used.

Before cooking, 12 lb of each variety were randomly chosen, removed from the freezer and package, mixed together, then divided into seven 735 g portions. Portions were placed in seven half-size shallow stainless steel steam table inset pans marked with holding times of 0, 10, 20, 30, 40, 50, and 60 minutes.

All pans of green beans were steamed at one time for ...


Functional Properties Of A Soy Isolate And A Soy Concentrate In Simple Systems As Related To Performance In A Food System, Cheryl Whetstone Hutton Aug 1975

Functional Properties Of A Soy Isolate And A Soy Concentrate In Simple Systems As Related To Performance In A Food System, Cheryl Whetstone Hutton

Doctoral Dissertations

Two commercial soy protein products, Promine-D (a soy isolate) and Promosoy-100 (a soy concentrate), with protein contents on a moisture-free basis of approximately 97 and 72% respectively, were studied. Part A of the study was,an investigation of protein solubility, hydration capacity, emulsion properties, fat absorptivity, and thickening function of the soy products in simple systems at pH levels of 5.0, 6.0, and 7.0 and at temperatures of 4 °, ambient (22-25°), and 90°C. The soy products were compared on both equal sample weight and equal protein bases. Part B involved evaluation of the functional performance of ...


Foodways Of Selected Mothers And Their Adult-Daughters In Upper East Tennessee, Kathryn Marianne Kolasa Jun 1974

Foodways Of Selected Mothers And Their Adult-Daughters In Upper East Tennessee, Kathryn Marianne Kolasa

Doctoral Dissertations

The similarities and differences in the food behavior, food preferences, mass media use, environmental factors and demographic characteristics of 11 selected mothers and their 15 adult-daughters in an homogenous rural area in Upper East Tennessee were studied. The degree of agreement between mother and adult-daughter in the variables named above was associated to their inter-personal communication, age, education and attitudes toward modernity and familism.

A field study method, including the use of repeated interviews, based on an extensive interview-schedule was used to define similarities and differences in behaviors and attitudes of the purposively sampled group of mothers and their adult-daughters ...


Protein-Phospholipid Interactions In Heated Phospholipid Emulsions Containing Bovine Myoglobin Or Sarcoplasmic Proteins, Sharon Lynn Melton Dec 1973

Protein-Phospholipid Interactions In Heated Phospholipid Emulsions Containing Bovine Myoglobin Or Sarcoplasmic Proteins, Sharon Lynn Melton

Doctoral Dissertations

A simplified procedure for determination of myoglobin concentration in aqueous muscle extract was developed. The procedure was used in an investigation of possible interactions between phospholipids and bovine myoglobin, either isolated or as a component of sarcoplasmic proteins. Investigation of the possible interactions was carried out as follows. Solutions containing myoglobin or sarcoplasmic proteins and emulsions (phospholipid, sarcoplasmic protein-phospholipid, and myoglobin-phospholipid) were heated from 25°C to end point temperatures up to 77°C. The following measurements were made on all protein dispersions; (1) pH; (2) percent protein remaining dispersed; (3) myoglobin concentration; (4) available lysine, basic group and acidic ...


Changes In Tenderness And Collagen Of Beef Semitendinosus Muscle Heated At Two Rates, Marjorie Porter Penfield Dec 1973

Changes In Tenderness And Collagen Of Beef Semitendinosus Muscle Heated At Two Rates, Marjorie Porter Penfield

Doctoral Dissertations

Tenderness, an important quality attribute of meat, is affected by many factors, including rate of heating. The purpose of this investigation was to study the changes occurring in beef semitendinosus muscle and intramuscular connective tissue heated at rates comparable to oven roasting at 93 and 149°C. The sequence of changes occurring during heating was followed by evaluating samples heated to four end points, 40, 50, 60, and 70°C. Cores of meat and isolated connective tissue samples in buffer were heated in a water bath "programmed" to produce the desired rate of heating.

As internal temperature increased Warner Bratzler ...


Staffing Patterns Of Dietetic Clinics, Katherine Hooper Benson Aug 1973

Staffing Patterns Of Dietetic Clinics, Katherine Hooper Benson

Doctoral Dissertations

Responsibilities and time demands of the dietetic clinic staff within institutions containing dietetic internships were investigated. Information was obtained from a questionnaire and observation of the diet instruction time records at the Dietetic Clinic at The University of Tennessee Memorial Research Center and Hospital (UTMRCH). The sample consisted of 45 dietetic clinics whose directors returned the completed instrument.

The staffing patterns of the dietetic clinics varied widely. There was a broad range of educational levels, man-hours worked, and defined responsibilities in the department, institution and community of the personnel in the participating clinics. Time averages are presented for some responsibilities ...


Thermal Conductivity And Related Properties Of Heated Ground Pectoral Turkey Muscles, Zoe Ann Holmes Aug 1972

Thermal Conductivity And Related Properties Of Heated Ground Pectoral Turkey Muscles, Zoe Ann Holmes

Doctoral Dissertations

Thermal conductivity, in association with characteristics of the thermodynamic medium at the food surface, establishes heat flow at the food boundary and reflects the transient properties meat has undergone during temperature change. The purpose of this research was to design and build an apparatus to measure thermal conductivity and to study some of the transient properties of ground pectoral turkey muscles.

Ground turkey pectoral muscles were heated in 9 increments from 77 to 185°F and held at end point temperature for 0 to 15 minutes. Thermal conductivity was calculated directly from data or indirectly by solving for diffusivity and ...


Relation Of Phospholipids To Selected Tissue Components In Light And Dark Portions Of Porcine Semitendinosus Muscle, Marian Dianne Ruff Aug 1970

Relation Of Phospholipids To Selected Tissue Components In Light And Dark Portions Of Porcine Semitendinosus Muscle, Marian Dianne Ruff

Doctoral Dissertations

The semitendinosus of pork contains a light and a dark portion that have physicochemical properties similar to those of uniformly white and red muscles, respectively. Although the two portions differ in metabolic activity they function as one muscle. The purpose of this study was to investigate the relation of phospholipid concentration to predominant fiber of the two portions of the porcine semitendinosus. The light and dark portions of the porcine semitendinosus were selected in order to minimize the possible effect of exercise on phospholipid content.

Phospholipids of the light and dark tissue of the porcine semitendinosus were studied in relation ...


Effect Of Cis-Trans Isomers And Related Physical Properties Of Monounsaturated Lipids On Shortening Power, Aneta Joyce Ostrander Aug 1968

Effect Of Cis-Trans Isomers And Related Physical Properties Of Monounsaturated Lipids On Shortening Power, Aneta Joyce Ostrander

Doctoral Dissertations

The effect of cis-trans isomers on the shortening power of lipids was investigated. Lipid samples studied included: a commercial vegetable oil (control), oleic acid, elaidinized triolein, two samples in which elaidinized oleic acid was substituted at different levels for oleic acid, and two samples in which elaidinized triolein was substituted at different levels for triolein. Breaking strengths of plain pastry wafers were used for estimating the shortening power. Melting point, surface tension, interfacial tension and viscosity measurements were made on the lipid samples. Lipid composition analyses included gas-liquid and thin-layer chromatography.

Except at the 100 percent level of substitution, wafers ...