Submitted to: UJNR Food & Agricultural Panel Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/15/2005
Publication Date: 10/23/2005
Citation: Musgrove, M.T., Jones, D.R., Cox Jr, N.A., Harrison, M., Northcutt, J.K. 2005. Determination of post-processing shell egg sanitizer efficacy. UJNR Food & Agricultural Panel Proceedings. p. 338-342.
Technical Abstract: In order to determine the effectiveness of post-processing shell egg sanitizers, choosing appropriate sampling methodology is crucial. Two common approaches for recovery of microorganisms from egg surfaces are shell rinses and crushing of shells/membranes. An experiment was conducted in which a shell rinse method was used in conjunction with a technique in which shell and membranes were crushed together. Eggs in various stages of process were sampled. Method efficacy for recovery of aerobic organisms and Enterobacteriaceae was determined for both methods. A second experiment was performed to determine if crush efficacy was hampered by first sampling eggs by the rinse method. Unwashed (PREP), in-process (INPR), and post-process eggs (POST) were evaluated in the study. Aerobic microorganism prevalence for eggshells sampled was similar for both methods (~100%) but log CFU/ mL were higher from SR than CR samples (3.2 and 2.2, respectively). Average Enterobacteriaceae recovery was similar for both methods (45% SR v. 40% CR) when all eggs were considered together. This population was detected more often by SR when PREP eggs were sampled (90% SR v. 56% CR), equally by SR and CR for INPR eggs (30% SR v. 29.3% CR) but more often by CR for POST eggs (10% SR v. 36% CR). SR was easier to perform and recovered larger numbers of aerobic organisms, particularly for PREP eggs. However, CR was more efficient for recovery of Enterobacteriaceae from POST eggs. Stage of shell egg processing may be an important consideration when choosing egg sampling methodology. After determining best sampling methodology, several potential sanitizers were compared with traditional compounds in two separate experiments. In the first trial, 1 mL of each compound was used on each unwashed egg. In a second experiment, a more realistic sanitizer application was developed. Sanitizers were applied after eggs passed through a simulated pilot washing device. In the subsequent experiment, it was determined that the wash procedure greatly reduced microbial numbers and prevalence. None of the sanitizers tested consistently reduced aerobic or yeast/mold populations.