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United States Department of Agriculture

Agricultural Research Service

2008 Annual Report

1a.Objectives (from AD-416)
There are 4 objectives for the project emphasizing food safety, quality, and security of shell eggs and egg products. First, to evaluate post-processing sanitizers and sanitizing technologies for their benefits to the microbiological safety and quality of shell eggs. Second, to develop technologies and/or techniques to improve processing plant sanitation practices. Third, to develop, evaluate and validate rapid detection methods for pathogens and toxins (for example: Staphylococcus aureus and staphylococcal enterotoxins, Listeria, Vibrio and Yersinia species) which could compromise food security in egg products, including liquid egg. Fourth, to examine differences in microbial flora associated with the eggs from alternative agriculture practices.

1b.Approach (from AD-416)
The five year project plan for the Egg Safety, Quality and Security ARS Research Program will address issues of concern for the shell egg and egg products industry, regulatory personnel, allied industry and consumers. Emphasis will be placed on determining the role post-processing shell surface sanitizers play in product safety and quality. Novel compounds as well as application technologies will be examined. Furthermore, processing plant sanitation will be more thoroughly assessed to determine points where interventions could increase sanitation program effectiveness. Procedures will include evaluating equipment surfaces for improved cleaning methods. This will be of particular interest for both regulators and the industry with the advent of new processing regulations. With the recent importance of food security, rapid detection techniques for potential biological terror pathogens that could be introduced into liquid egg product will be evaluated. Through this objective, a greater understanding of intercepting potential agricultural threats will be gleaned. This project plan encompasses a large body of work that will result in safer, higher quality shell eggs and egg products for the consumer. Agricultural production practices have become more diverse to meet consumer demands. The microbial flora of eggs from alternative production will be compared to traditional production to gain a better understanding of their potential impact on egg safety.

3.Progress Report
Presentations were made to scientific, regulatory and egg industry groups to transfer findings of egg shell surface sanitizer work. USDA Agricultual Marketing Service Poultry Programs (USDA-AMSPP) initiated further dialog focused on the efficacy of the required post-processing shell surface sanitizing rinse.

Studies were conducted to determine the ability of sanitizing compounds to reduce the population of Enterobacter cloacae (most frequently isolated organism in comercial setting) on the surface of inoculated vacuum loader cups. An additional study monitored the physical changes of clean vacuum loader cups when exposed to 20 consecutive applications of the same sanitizing compounds.

An extensive study examining the differences in bacterial populations, including human pathogens, associated with the housing environment and eggs from sister flocks of commercial caged egg layers and free range layers was initiated with a university collaborator. The study will be for the 80 week life cycle of the flock.

Efforts continued with other ARS scientists to enhance the egg micro-crack detection system. Discussions with USDA-AMSPP personnel focused on adjusting the system and software for maximum usability. Demonstrations of the system (including in plant)and a study of 1000 eggs was conducted to compare the effectiveness of the imaging system and trained professional graders.

A further study examined the effects of exposure to the micro-crack system on the physical quality of shell eggs during cold storage to determine any adverse effects. Another study was conducted to see if the micro-crack system induced cracking in poor shell quality eggs.

A project was conducted with another unit scientist to determine if correlations exist between Salmonella penetration of the yolk and yolk physical quality. Eggs from six laying strains maintained in the same laying facility were compared.

A continuation of reserch with another ARS scientist analyzed the dielectric properties of eggs during storage and yolk quality factors. The research is an attempt to devise rapid quality predicting measurements for the egg industry.

A study compared microbial biofilms on processing equipment and analyses of shell eggs and air samples. Samples with the highest numbers of aerobic organisms and Enterobacteriaceae were most likely to also be contaminated by Salmonella. Salmonella positive eggs were detected after contact with these post-wash egg-contact equipment surfaces.

A study with another ARS scientist determined that blood spots in eggs did not increase Salmonella viability.

In another study, egg shell strength was measured after eggs were washed with water pH 9 or pH 12 and no differences were found. Though the USDA Agricultural Marketing Service guidelines for wash water used to clean shielded eggs do not include a pH minimum it has been determined that higher pH levels (>11) reduce Salmonella prevalence.

This research addresses National Program 108 (Food Safety), Component 1.2 Pathogens, Toxins and Chemical Contaminants Postharvest, Problem Statement 1.2.4 (Processing Interventions and Strategies).

1. Assess application technologies and techniques for processing facility sanitation compounds. Vacuum loader cups in shell egg processing facilities have been identified as reservoirs of bacterial populations. Five sanitizing compounds were compared for their ability to reduce bacterial loads. The 200 ppm. sodium hypochlorite and 200 ppm. calcium hypochlorite treatments reduced bacterial levels to those comparable with the uninoculated controls. Both of these compounds could be easily applied in the processing facility with low potential of harm to employees or processing equipment and are affordable sanitizing options.

This research addresses National Program 108 (Food Safety), Component 1.2 Pathogens, Toxins and Chemical Contaminants Postharvest, Problem Statement 1.2.4 (Processing Interventions and Strategies).

5.Significant Activities that Support Special Target Populations

6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings12
Number of Newspaper Articles and Other Presentations for Non-Science Audiences2

Review Publications
Jones, D.R., Musgrove, M.T. 2008. Assessment of Microbial Contaminants Present on Vacuum Loaders in Shell Egg Processing Facilities. Journal of Food Safety.28(3):346-354.

Jones, D.R., Musgrove, M.T. 2007. Pathogen prevalence and microbial levels associated with restricted shell eggs. Journal of Food Protection.70(9):2004-2007

Musgrove, M.T., Northcutt, J.K., Jones, D.R., Cox Jr, N.A., Harrison, M.A. 2008. Enterobacteriaceae and Related Organisms Isolated from Shell Eggs Collected During Commercial Processing. Poultry Science. 87:1211-1218.

Musgrove, M.T., Jones, D.R., Hinton Jr, A., Ingram, K.D., Northcutt, J.K. 2008. Running title: Yeasts from refrigerated commercial shell eggs. Journal of Food Protection:71:1258-1261

Patterson, P.H., Koelkebeck, K.W., Anderson, K.E., Darre, M.J., Carey, J.B., Ahn, D.U., Ernst, R.A., Kuney, D.R., Jones, D.R. 2008. Temperature sequence of eggs from oviposition through distribution: Production – part 1. Poultry Science.87(6):1182-1186.

Koelkebeck, K.W., Patterson, P.H., Anderson, K.E., Darre, M.J., Carey, J.B., Ahn, D.U., Ernst, R.A., Kuney, D.R., Jones, D.R. 2008. Temperature Sequence of Eggs from Oviposition Through Distribution: Processing - Part 2. Poultry Science.87(6):1187-1194.

Anderson, K.E., Patterson, P.H., Koelkebeck, K.W., Darre, M.J., Carey, J.B., Ahn, R.A., Ernst, R.A., Kuney, D.R., Jones, D.R. 2008. Temperature Sequence of Eggs from Oviposition through Distribution: Transportation Part 3. Poultry Science.87(6):1195-1201.

Lawrence, K.C., Yoon, S.C., Heitschmidt, G.W., Jones, D.R., Park, B. 2008. Imaging system with modified-pressure chamber for crack detection in shell-eggs. Sensing and Instrumentation for Food Quality and Safety.2:116-122

Jones, D.R., Musgrove, M.T. 2008. Identification of Enterobacteriaceae on Vacuum Loaders in Shell Egg Processing. Poultry Science.87(8):1678-1681

Smith, D.P., Musgrove, M.T. 2008. Effect of blood spots on table egg albumen on Salmonella growth. Poultry Science. 87: 1659-1661

Last Modified: 11/30/2015
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