Egg Safety and Quality Research Unit

Athens, GA, United States

Egg Safety and Quality Research Unit

Athens, GA, United States
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Hannah J.F.,University of Georgia | Wilson J.L.,University of Georgia | ox N.A.,Poultry Microbiological Safety Research Unit | ason J.A.,Poultry Processing and Swine Physiology Research Unit | And 5 more authors.
Poultry Science | Year: 2011

These studies evaluated the bacterial level of unwashed and washed shell eggs from caged and cage-free laying hens. Hy-Line W-36 White and Hy-Line Brown laying hens were housed on all wire slats or all shavings floor systems. On the sampling days for experiments 1, 2, and 3, 20 eggs were collected from each pen for bacterial analyses. Ten of the eggs collected from each pen were washed for 1 min with a commercial egg-washing solution, whereas the remaining 10 eggs were unwashed before sampling the eggshell and shell membranes for aerobic bacteria and coliforms (experiment 1 only). In experiment 1, the aerobic plate counts (APC) of unwashed eggs produced in the shavings, slats, and caged-housing systems were 4.0, 3.6, and 3.1 log10 cfu/mL of rinsate, respectively. Washing eggs significantly (P < 0.05) reduced APC by 1.6 log10 cfu/ mL and reduced the prevalence of coliforms by 12%. In experiment 2, unwashed eggs produced by hens in triple-deck cages from 57 to 62 wk (previously housed on shavings, slats, and cages) did not differ, with APC ranging from 0.6 to 0.8 log10 cfu/mL. Washing eggs continued to significantly reduce APC to below 0.2 log10 cfu/mL. In experiment 3, the APC for unwashed eggs were within 0.4 log below the APC attained for unwashed eggs in experiment 1, although hen density was 28% of that used in experiment 1. Washing eggs further lowered the APC to 0.4 to 0.7 log10 cfu/mL, a 2.7-log reduction. These results indicate that shell bacterial levels are similar after washing for eggs from hens housed in these caged and cage-free environments. However, housing hens in cages with manure removal belts resulted in lower APC for both unwashed and washed eggs (compared with eggs from hens housed in a room with shavings, slats, and cages). © 2011 Poultry Science Association Inc.

Holt P.S.,Egg Safety and Quality Research Unit | Davies R.H.,Veterinary Laboratories Agency | Dewulf J.,Ghent University | Gast R.K.,Egg Safety and Quality Research Unit | And 4 more authors.
Poultry Science | Year: 2011

A move from conventional cages to either an enriched cage or a noncage system may affect the safety or quality, or both, of the eggs laid by hens raised in this new environment. The safety of the eggs may be altered either microbiologically through contamination of internal contents with Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) or other pathogens, or both, or chemically due to contamination of internal contents with dioxins, pesticides, or heavy metals. Quality may be affected through changes in the integrity of the shell, yolk, or albumen along with changes in function, composition, or nutrition. Season, hen breed, flock age, and flock disease-vaccination status also interact to affect egg safety and quality and must be taken into account. An understanding of these different effects is prudent before any large-scale move to an alternative housing system is undertaken.© 2011 Poultry Science Association Inc.

Jones D.R.,Egg Safety and Quality Research Unit | Lawrence K.C.,U.S. Department of Agriculture | Yoon S.C.,U.S. Department of Agriculture | Heitschmidt G.W.,U.S. Department of Agriculture
Poultry Science | Year: 2010

Cracks in the shell surface compromise the primary barrier for external microbial contamination of the egg. Microcracks are very small cracks in the shell surface that are difficult to detect by human graders. New technology has been developed that uses modified pressure and imaging to detect microcracks in eggs. Research has shown the system to have an accuracy of 99.6% in detecting both cracked and intact eggs. A study was undertaken to determine if quality differences existed between modified pressure imaged and control eggs during extended cold storage. Three replicates were conducted with eggs stored at 4°C for 5 wk with weekly quality testing. The physical quality factors monitored were Haugh units, albumen height, egg weight, shell strength, vitelline membrane strength and elasticity, and whole egg total solids. All measurements were conducted on individual eggs (12/treatments per replicate) each week with the exception of whole egg solids, which were determined from 3 pools (4 eggs each)/treatment per replicate each week. Percentage of whole egg total solids was the only significant difference (P < 0.05) between treatments (23.65% modified pressure imaged and 23.47% control). There was a significant difference (P < 0.05) for egg weight between replicates (60.82, 58.02, and 60.58 g for replicates 1, 2, and 3, respectively). Therefore, imaging eggs in the modified pressure system for microcrack detection did not alter egg quality during extended cold storage. Utilizing the modified pressure crack detection technology would result in fewer cracked eggs reaching the consumer, consequently enhancing food safety without affecting product quality.

Karcher D.M.,Michigan State University | Jones D.R.,Egg Safety and Quality Research Unit | Abdo Z.,U.S. Department of Agriculture | Zhao Y.,Iowa State University | And 2 more authors.
Poultry Science | Year: 2015

The US egg industry is exploring alternative housing systems for laying hens. However, limited published research related to cage-free aviary systems and enriched colony cages exists related to production, egg quality, and hen nutrition. The laying hen's nutritional requirements and resulting productivity are well established with the conventional cage system, but diminutive research is available in regards to alternative housing systems. The restrictions exist with limited availability of alternative housing systems in research settings and the considerable expense for increased bird numbers in a replicate due to alternative housing system design. Therefore, the objective of the current study was to evaluate the impact of nutrient and energy intake on production and egg quality parameters from laying hens housed at a commercial facility. Lohmann LSL laying hens were housed in three systems: enriched colony cage, cage-free aviary, and conventional cage at a single commercial facility. Daily production records were collected along with dietary changes during 15 production periods (28-d each). Eggs were analyzed for shell strength, shell thickness, Haugh unit, vitelline membrane properties, and egg solids each period. An analysis of covariance (ANCOVA) coupled with a principal components analysis (PCA) approach was utilized to assess the impact of nutritional changes on production parameters and monitored egg quality factors. The traits of hen-day production and mortality had a response only in the PCA 2 direction. This finds that as house temperature and Met intake increases, there is an inflection point at which hen-day egg production is negatively effected. Dietary changes more directly influenced shell parameters, vitelline membrane parameters, and egg total solids as opposed to laying hen housing system. Therefore, further research needs to be conducted in controlled research settings on laying hen nutrient and energy intake in the alternative housing systems and resulting impact on egg quality measures. © © The Author 2015. Published by Oxford University Press on behalf of Poultry Science Association.

Sommers C.H.,U.S. Department of Agriculture | Sites J.E.,U.S. Department of Agriculture | Musgrove M.,Egg Safety and Quality Research Unit
Journal of Food Safety | Year: 2010

Ultraviolet Light (254 nm) is a U.S. Food and Drug Administration-approved nonthermal intervention technology that can be used for decontamination of food surfaces. In this study, the use of ultraviolet light (UV-C) at doses of 0.5-4.0 J/cm2 to inactivate a cocktail of Salmonella spp., Listeria monocytogenes and Staphylococcus aureus that were surface-inoculated on frankfurters, bratwurst, shell eggs, chicken drumsticks, boneless skinless chicken breasts, boneless pork chops, tomatoes and jalapeno peppers was investigated. The pathogens displayed similar sensitivities to UV-C on individual food products. Pathogen reductions ranged from approximately 0.5 log/g on raw meat and poultry to almost 4 log/g on tomatoes, while the pathogens were not recovered from stainless steel at a UV-C dose of 0.4 J/cm2. Use of UV-C light should be given serious consideration as a technology for routine surface decontamination of food contact surfaces and appropriate food products. Published 2010. This article is a US Government work and is in the public domain in the USA.

McQuestin O.J.,University of Tasmania | Musgrove M.T.,Egg Safety and Quality Research Unit | Tamplin M.L.,University of Tasmania
Food Microbiology | Year: 2010

The potential impact of post-pasteurisation contamination of liquid egg products with the multi-antibiotic resistant pathogen Salmonella enterica serotype Typhimurium definitive type 104 (DT104) was assessed by determining the viability of this bacterium in whole egg, albumen and 10% w/w sugared and salted yolk incubated at 4-42 °C. Results indicated that populations of S. Typhimurium DT104 were slowly inactivated in all four products when stored at 4 °C. However, based on the typical shelf-lives of cold-stored liquid egg, less than 0.6 log-kill would be achieved in those products prior to their use. Incubation at temperatures pertaining to abuse situations (10, 15, 20 and 25 °C) revealed an increasing potential for growth of S. Typhimurium DT104 in whole egg, albumen and sugared yolk, as indicated by trends in growth rate, lag duration and maximum population density. At even higher temperatures (30, 37 and 42 °C), growth rates of S. Typhimurium DT104 in whole egg and sugared yolk continued to increase. The same was true for S. Typhimurium DT104 in albumen except that growth was not observed at 42 °C and instead populations were inactivated within 30 h. At no temperature tested was S. Typhimurium DT104 able to grow in salted yolk. The influence of these growth and inactivation patterns on the risk of salmonellosis in relation to product type and storage temperature is discussed. © 2009 Elsevier Ltd.

Musgrove M.T.,Egg Safety and Quality Research Unit | Northcutt J.K.,Clemson University
International Journal of Poultry Science | Year: 2012

Improved sanitation procedures during shell egg processing may reduce the risk of food-borne illness. Experiments were conducted to determine the ability of an alcohol-quaternary ammonium sanitizer or water to reduce Salmonella inoculated onto stainless steel and shell egg processing equipment. A nalidixic acid-resistant Salmonella typhimurium (ST) isolate was grown on agar plates at 37°C for 18-24 h; cells were harvested and added to Phosphate Buffered Saline (PBS) to generate 8.5 Salmonella cells/mL inoculum in two experiments. Both experiments were repeated twice. In the first experiment four stainless steel beakers were contaminated by spraying 10 mL of inoculum, respectively. Beakers were allowed to dry for 15 min. Two of the beakers were sprayed with 20 mL of water and the other two were sprayed with a sanitizer solution (70% isopropyl alcohol and 200 ppm quaternary ammonium). After 5 min and 24 h each beaker was swabbed with a PBS moistened sponge and plated onto BGS supplemented with 200 ppm nalidixic acid to enumerate surviving ST. In the second experiment, inoculum was sprayed onto two brushes from shell egg packing machinery. After 15 min, one brush was sprayed with water for five min and the other was sprayed with the sanitizer for 30 s. Each brush was sampled by swabbing three times after 5 min and 24 h. After 5 min, 5.5 and 0.6 log CFU/mL ST and after 24 h, 2.8 and 0.0 log CFU/mL ST were recovered from stainless steel, respectively. Packer head brush average results were 4.7 and 3.1 log CFU/mL ST after 5 min and were 4.0 and 0.00 log CFU/ml ST after 24 h. This sanitizer solution and delivery system were 100 to 10,000 times more effective than water in reducing Salmonella numbers. © Asian Network for Scientific Information, 2012.

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