:Spoilage of Eggs
- Contamination of eggs:
Freshly laid egg is sterile but the egg shell soon becomes contaminated by fecal matter of hen by nest, by washing water, by handling and by other material in which it is stored.
If a total number of micro-organisms per shell of hen’s egg has been reported to range from 102-107 with average of 105.
Salmonella spp. may be found on shell or inside egg.
- Non-microbial spoilage of eggs:
These include loss of moisture and hence loss of weight during long term storage.
Change in physical state of egg contents also occur during long term storage.
They include thinning of egg white and breaking of yolk membrane.
As the yolk membrane weaken and break, yolk becomes flat and homogenously mixed in egg white. - Microbial spoilage of eggs:
In order to cause spoilage of shell of egg, microorganisms must contaminate the shell, penetrate through the pores in shell and inner membrane, reach the eggwhite and yolk and grow there.
Some microorganisms cannot grow in egg white but can grow rapidly in egg yolk.
Change in storage temperature facilitates penetration of organism through shell and hence facilitates microbial spoilage.