Influence of egg handling and storage on the occurrence of spoilage organisms in shell eggs.

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

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Eggs are an affordable, nutrient dense food which is a major international trade commodity. Differing international egg handling and storage regulations have become a barrier to the importation and exportation of shell eggs. The current study was undertaken to determine the impact of common egg handling and egg storage conditions on egg physical and microbial quality. The current presentation focuses on egg spoilage organisms. Eggs were obtained (n = 5,760) from a commercial shell egg processor. Eggs were collected under four different egg handling treatments: 1) unwashed (nest run), 2) washed (according to USDA Agricultural Marketing Service guidelines), 3) washed and oiled (food-grade mineral oil), and 4) 21 days stored and then washed. Two cases of eggs (n = 720) for each replicate (n = 3) from each egg handling conditions were placed in refrigeration (4°C) or room temperature (22°C). At wk 0, 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 26, six eggs were randomly selected from each replicate combination of egg handling and storage temperature treatments. Beginning at 8 weeks of storage in the room temperature treatments, spoiled eggs were observed. Spoiled eggs were identified by visible growth on the shell membrane or egg content and color changes of the egg contents and spread plated onto Standard Methods Agar. Up to three unique colonies, based on morphology, were selected and passed twice to obtain a pure culture. Egg handling treatment impacted the the diversity of species (richness) and number of an individual species (abundance) of spoilage organisms in spoiled eggs. . Egg contents of unwashed eggs had less richness of spoilage organisms than washed and oiled eggs . Washed and oiled eggs and eggs held for 21 days and then washed had greater abundance of spoilage organisms in the egg contents compared to unwashed eggs. Spoiled eggs were not observed in any egg handling treatments held in refrigeration (4°C). This study shows the importance of refrigeration of shell eggs regardless of egg handling to prevent egg spoilage.

Technical Abstract: Eggs are an affordable, nutrient dense food which is a major international trade commodity. Differing international egg handling and storage regulations have become a barrier to the importation and exportation of shell eggs. The current study was undertaken to determine the impact of common egg handling and egg storage conditions on egg physical and microbial quality. The current presentation focuses on egg spoilage organisms. Eggs were obtained (n = 5,760) from a commercial shell egg processor. Eggs were collected under four different egg handling treatments: 1) unwashed (nest run), 2) washed (according to USDA Agricultural Marketing Service guidelines), 3) washed and oiled (food-grade mineral oil), and 4) 21 days stored and then washed. Two cases of eggs (n = 720) for each replicate (n = 3) from each egg handling conditions were placed in refrigeration (4°C) or room temperature (22°C). At wk 0, 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 26, six eggs were randomly selected from each replicate combination of egg handling and storage temperature treatments. Beginning at 8 weeks of storage in the room temperature treatments, spoiled eggs were observed. Spoiled eggs were identified by visible growth on the shell membrane or egg content and color changes of the egg contents and spread plated onto Standard Methods Agar. Up to three unique colonies, based on morphology, were selected and passed twice to obtain a pure culture. Egg handling treatment impacted the the diversity of species (richness) and number of an individual species (abundance) of spoilage organisms in spoiled eggs. Organisms were then identified with the use of a MALDI-TOF. Egg contents of unwashed eggs had less richness of spoilage organisms than washed and oiled eggs (P < 0.03). Washed and oiled eggs (P < 0.03) and eggs held for 21 days and then washed (P < 0.01) had greater abundance of spoilage organisms in the egg contents compared to unwashed eggs. Spoiled eggs were not observed in any egg handling treatments held in refrigeration (4°C). This study shows the importance of refrigeration of shell eggs regardless of egg handling to prevent egg spoilage.