Saturday, November 15, 2014

Sous vide pasteurized eggs Part 2 自家製滅菌卵パート2

After I posted sous vide home pasteurized shell eggs, an anonymous reader let me know of the existence of an article by Dr. Schuman (see below, reference #1) which more clearly indicated the safe parameters for shell egg pasteurization with bacterial culture results. That is at 57C (134.6F) for 75 minutes (please see the chart below).

I used 54.5C (130F) for 2 hours in my previous post. I meant to try this new parameter for pasteurizing shell eggs for some time but finally got around to it. As I expected, at 57C,  the egg white became slightly denatured and opaque. The consistency was slightly firmer than the previous method (see below).

57C(134.6F) for 75 minutes
Although the background (container) is different, you can see that the egg white is clearer using the 130F for 2 hours method (below).

54.5C (130F) for 120 minutes
Using the two eggs pasteurized at 57C for 75 minutes, I made a French omelet. Although it took a bit more effort to beat the eggs, these pasteurized eggs can be used like any other shell egg. Sunny-side up fried eggs, poached and soft boiled eggs should not have any problem, although I have not tried it.

My conclusion: At 57C for 75 minutes, pasteurization of shell eggs by immersion in heated water, is totally safe from salmonella.  Although the consistency and appearance of the egg white is altered. Making egg dishes using these eggs should be the same as if raw eggs were used. The only area about which I am not sure and will need to try is making whipped egg white from pasteurized egg whites (which would be especially useful for dishes such as French sorbet since cooking egg white would not be possible).

I also believe that pasteurization at 56C for 2 hours or longer will produce "reasonably" safe pasteurized eggs but this conclusion appears to lack rigorous bacterial culture results. The egg whites look and behave more like raw egg white.

*Just in case you are interested. These charts are from the reference #1. This is based on sensitive culture study until no salmonella was detectable. Dr. Schuman (reference #1) only tested 57C and 58C. So, we do not know at 55C, how long it will take before salmonella is not detectable.
pasteurized eggs charts in JPEG

  1. Schuman JD, Sheldon BW, Vandepopuliere JM, and Ball HR Jr. Immersion heat treatments for inactivation of Salmonella enteritidis with intact eggs J Appl Microbiol. 1997 Oct;83(4):438-44.
  2.  USDA Document "Pasteurization of Liquid Egg Products and Shell Eggs"

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