ShareCooling helps eggs fight salmonella
A team from Purdue University has demonstrated that lysozyme activity could be increased by as much as 50%, thanks to the addition of carbon dioxide or to a cooling process which causes carbon dioxide to be sucked inside the shell.
Eggs contain an enzyme called lysozyme, which defends egg whites from bacteria. Once eggs are laid, their natural resistance to pathogens starts dropping as the lysozyme becomes less active, in direct relation with lower carbon dioxide contents and higher pH levels.
A team from Purdue University has demonstrated that lysozyme activity could be increased by as much as 50%, thanks to the addition of carbon dioxide or to a cooling process which causes carbon dioxide to be sucked inside the shell. The additional lysozyme activity enables eggs to eliminate harmful bacteria over a longer period.
The cooling is achieved thanks to solid carbon dioxide (dry ice) used to rapidly lower the eggs’ temperature then by circulating carbon dioxide gas at -75°C around the eggs placed in a cold chamber. A thin layer of ice then forms inside the eggshell. After treatment, the ice layer thaws, quickly lowering the eggs’ internal temperature to under 7°C, without the shell cracking as it can resist expansion from a thin ice layer.
According to USA Food and Drug Administration (FDA) studies, if eggs were cooled and stored at 7°C or under within 12 hours of laying, there would be an estimated 100 000 fewer cases of salmonella illnesses from eggs in the USA each year.
A team from Purdue University has demonstrated that lysozyme activity could be increased by as much as 50%, thanks to the addition of carbon dioxide or to a cooling process which causes carbon dioxide to be sucked inside the shell. The additional lysozyme activity enables eggs to eliminate harmful bacteria over a longer period.
The cooling is achieved thanks to solid carbon dioxide (dry ice) used to rapidly lower the eggs’ temperature then by circulating carbon dioxide gas at -75°C around the eggs placed in a cold chamber. A thin layer of ice then forms inside the eggshell. After treatment, the ice layer thaws, quickly lowering the eggs’ internal temperature to under 7°C, without the shell cracking as it can resist expansion from a thin ice layer.
According to USA Food and Drug Administration (FDA) studies, if eggs were cooled and stored at 7°C or under within 12 hours of laying, there would be an estimated 100 000 fewer cases of salmonella illnesses from eggs in the USA each year.