Life Sciences Commons^™

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 …

Developing, Refining, And Validating A Survey To Measure Adolescent Food Safety Self-Efficacy, Monica K Brandon

Masters Theses

Self-efficacy is a proven indicator of predicting risky behaviors, but without a baseline level of adolescent food safety self-efficacy to develop targeted interventions it is difficult to produce meaningful behavior change. The research question around which this study was designed is: To what extent can a validated instrument accurately capture adolescent beliefs of food safety self-efficacy. Through rigorous field testing and statistical analysis we hypothesize a valid and reliable instrument can be created for measuring adolescents’ food safety self-efficacy. The purposes of this study included: (a) development of a high quality, food safety self-efficacy instrument, (b) validation of the instrument …

Antimicrobial Activity Of Casein Hydrolysates Against Listeria Monocytogenes And Escherichia Coli O157:H7, Jessica M Christman

Masters Theses

Listeriosis has the highest fatality and hospitalization rate among foodborne illnesses. Listeria monocytogenes causes listeriosis and is a difficult bacterium for ready-to-eat food processors to eliminate because of its ability to grow in the absence of oxygen and under refrigeration. Recently, milk and its proteins have gained recognition as the largest source of biologically active peptides, and, it stands reason that several antimicrobial peptides (AMP) can be released from casein as it is the most abundant milk protein. AMPs are commonly obtained by cutting the whole protein into peptide fragments using enzymes or by acidification. The objective of this study …

Novel Approaches For The Efficient Sampling And Detection Of Listeria Monocytogenes And Brochothrix Thermosphacta On Food Contact Surfaces, Jessica Anne Clemons

Masters Theses

The primary step in the microbiological assessment of highly dynamic and complex food processing conditions is environmental sampling. The objectives of this study were to: (1) compare the efficacy of four sampling devices including Microbial-Vac system (MV), cellulose sponge (SP), polyester swab (SW) and composite tissue (CT), for the recovery of Listeria monocytogenes and Brochothrix thermosphacta on five surfaces and (2) to determine if there was a significant difference between the recovery of low (10 CFU/900cm²) and high (100 CFU/900cm²) L. monocytogenes inoculum levels using the sampling devices in a simulated food processing environment. Surfaces used …

Physical Characteristics And Metal Binding Applications Of Chitosan Films, Joshua B. Jones

Masters Theses

Chitosan films are an excellent media for binding metal ions due to the electrostatic nature of the chitosan molecules. Addition of cross-linking or plasticizing agents alters texture of the films, but their effect on metal-binding capacity has not been fully characterized. The objective of this research was to determine effects of plasticizers and cross-linkers on physical and metal-binding properties of chitosan films and coatings prepared by casting and by spincoating. Chitosan films were prepared using 1% w/w chitosan in 1% acetic acid with or without (control) additives. Plasticizing agents were tetraethylene glycol (TEG) and glycerol while citric acid, ethylenediamine tetraacetic …

Volume 7, Number 2 (Spring/Summer 2010), Ut Institute Of Agriculture

Tennessee Land, Life and Science Magazine

Issue Highlights:

• Celebrating UT Extension and 4-H's Centennial
• A Veterinarian Alum Blogs on His Life, Work
• Workshops and Tours Promote Direct Farm Marketing

Impacts Of Supercritical Extraction On Gc/Ms Profiles Of Volatiles In Whey Protein Isolate Sampled By Solid Phase Microextraction, May Lamsen

Masters Theses

Whey protein isolate (WPI) contains at least 90% protein and should ideally possess a bland flavor without typical dairy flavors including sweet aromatic and cooked/milky notes. However, its flavor may be highly variable due to factors including original whey source, processing and storage conditions. Novel technologies removing nonpolar compounds responsible for off-flavors and off-flavor formations are desirable. The major objective of this research was to evaluate impacts of supercritical carbon dioxide (scCO2) extraction, a known green process, on volatile profiles of WPI. A prior sub-objective was to establish an analytical technique for characterization of volatiles. Specifically, adsorption conditions in a …

Volume 7, Number 1 (Fall/Winter 2010), Ut Institute Of Agriculture

Tennessee Land, Life and Science Magazine

Issue Highlights:

• UT AgResearch Discoveries that Make a Difference
• Taking Steps to Protect U.S. Agriculture and Food Supply
• Student Biosystems Teams Shine in International Competitions