Research Note: Impact of egg handling and egg storage temperature on the growth of spoilage organisms in shell eggs.

Authors: Garcia, Javier; Jones, Deana; Read, Quentin; Gast, Richard; HARDMAN, VANESSA - University Of Georgia

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: The current study examined the impact of egg handling and storage on of spoilage organisms in shell eggs. Eggs processed under different egg handling treatments (1: unwashed; 2: washed; 3: washed and oiled; 4: stored for 21 days then washed) were collected and placed in storage at either refrigeration (4°C) or room temperature (22°C). Six eggs from each handling treatment and storage treatment were randomly selected at each sampling period (week 0, 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 26). Spoiled eggs did not occur in the refrigerated eggs regardless of egg handling treatment. Eggs stored at room temperature began to spoil at about 8 weeks. Microbial populations between the egg handling treatments did differ with the most common bacterial species recovered in unwashed egg being Escherichia coli, Pseudomonas spp. in washed and washed and oiled eggs and Alcaligenes faecalis spp. faecalis in 21-day stored and washed eggs. In the number of species in a community (richness) recovered from the egg contents, washed and oiled eggs and 21-day stored and washed eggs had more bacterial richness compared to the egg contents of the unwashed eggs. Similarly, in the washed and oiled eggs and 21-day stored and washed eggs, the number of individuals in a community (abundance) of microorganisms in the egg contents were greater than in the egg contents of unwashed eggs. This study demonstrates the importance of refrigeration of shell eggs regardless of egg handling treatment in preventing spoilage. Egg handling treatments do impact the presence of spoilage microorganisms when stored at room temperature.

Technical Abstract: The current study examined the impact of egg handling and storage on the occurrence of spoilage organisms in shell eggs. Eggs processed under different egg handling treatments (1: unwashed; 2: washed; 3: washed and oiled; 4: stored for 21 days then washed) were collected and placed in storage at either refrigeration (4°C) or room temperature (22°C). Six eggs from each handling treatment and storage treatment were randomly selected at each sampling period (week 0, 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 26). Spoiled eggs were not observed in the refrigerated eggs regardless of egg handling treatment. Eggs stored at room temperature began to spoil at about 8 weeks. Microbial populations between the egg handling treatments did differ with the most common bacterial species recovered in unwashed egg being Escherichia coli, Pseudomonas spp. in washed and washed and oiled eggs and Alcaligenes faecalis spp. faecalis in 21-day stored and washed eggs. In the richness (number of species in a community) of bacterial species recovered from the egg contents, washed and oiled eggs and 21-day stored and washed eggs had more bacterial richness compared to the egg contents of the unwashed eggs. Similarly, in the washed and oiled eggs and 21-day stored and washed eggs abundance (number of individuals in a community) of microorganisms in the egg contents were greater than in the egg contents of unwashed eggs. This study demonstrates the importance of refrigeration of shell eggs regardless of egg handling treatment in preventing spoilage. Egg handling treatments do impact the presence of spoilage microorganisms when stored at room temperature.