PhD Food Science defence "Thermal Stability of Encapsulated Listeria Bacteriophage and Its Efficacy Against Listeria monocytogenes in Ready-To-Eat Meats"
Date and Time
Food Science lecture room 128
Final Examination for the Degree of PhD - HANIE AHMADI
Dr. Yoshi Mine, Chair
Dr. Loong-Tak Lim, Advisor
Dr. Sampathkumar Balamurugan, Co-Advisor
Dr. Keith Warriner, Department Member
Dr. Claudia Narvaez, External Examiner
TITLE: Thermal Stability of Encapsulated Listeria Bacteriophage and Its Efficacy Against Listeria
monocytogenes in Ready-To-Eat Meats
ABSTRACT: This research explored the use of encapsulated lytic Listeria phages as an additive in ready-to-eat (RTE) meats for controlling the growth of Listeria monocytogenes. The thermal stability of Listeria phages at typical RTE processing temperatures were evaluated using temperatures simulating typical preparation of RTE meats. Thermal stability of bacteriophages, encapsulated in sodium alginate/gum Arabic/gelatin matrices, was evaluated. The optimal polymer concentrations for enhancing the thermal stability of encapsulated phage were determined using a response surface methodology. In addition, the efficacy of adding a bacteriophage as an additive to cooked meat products was investigated. Results from this study suggested there was a significant (P<0.05) difference between thermal stability of two Listeria phages. Encapsulation procedure significantly (P<0.05) enhanced phage thermal stability. Moreover, using bacteriophage as an additive in cooked meat products was not effective in inhibiting the growth of L. monocytogenes, especially those present within the meat matrices. Phage application was most effective when applied to the surface and only against surface contamination.