> I finally found the detail about this.  Raw egg whites contain avidin,
> which prevents biotin from being processed.  Considered part of the B
> complex group of vitamins, biotin is necessary for the metabolism of
> carbohydrates, fats, and amino acids (the building blocks of protein).
> But in fertile eggs embryonic tissue (in the yolk) contains biotin that
> can be utilized without being blocked.  So that is why the fertile eggs
> are recommended over the infertile ones - to get the usable biotin.

do you mean that biotin is present only in fertile eggs .?
jean-claude