Food Science Commons^™

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 of molecular weight, chitosan …

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 M phosphate buffer (pH 7.0), …

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 …