Abstract
Microbial contamination of egg shells is of great importance in the commercial production of table eggs. The objective of the present project was to determine the effectiveness of an iodine based disinfectant (IBD) on the microbial population of egg shell surfaces. Aerobic plate counts (APCs) and egg shells inoculated with Salmonella typhimurium and Salmonella enteritidis were evaluated under simulated industry egg processing conditions with a commercial egg washer used as the delivery system for sanitizers. Sanitizing treatments consisted of distilled deionized water (DDW), IBD, and chlorine (CL; 200 ppm). Enumeration of aerobic plate populations indicated that IBD and CL treatment significantly (p < 0.05) decreased microbial populations on the shell compared to DDW treatment when egg wash water total dissolved solids were low (2.02 - 2.03 g/l) and wash water APC was high (5.05 - 5.85 log CFU/ml). When egg wash water total dissolved solids was high (2.47 g/l) and wash water APC was low (3.69 log CFU/ml) sanitizers were not effective in reducing egg shell microbial populations. No difference in egg shell APC counts was detected between the IBD and CL. All treatments (DDW, IBD and CL) significantly (p < 0.05) decreased Salmonella spp. populations on the shell compared to dry (no spray) egg controls. In order to examine the effect of starvation, 1, 5, and 10d old cultures of S. typhimurium and S. enteritidis poultry isolates were grown in TSB media were used for inoculation of eggs. All sanitizer treatments significantly (p<0.05) decreased the cell population compared to respective dry egg control, regardless of physiological status of the culture. The objective of the microbial levels in processing plants project was to evaluate the aerobic plate counts (APCs) of egg shells in both in-line and off-line egg processing facilities at selected sites throughout the processing procedure.
Knape, Koyle Dean (2000). Comparison of different disinfectants on egg shell microbial populations and evaluation of microbial levels in commercial egg processing facilities. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -K544.