A good egg

UK and Dutch scientists have mimicked an ancient Chinese culinary technique of preserving eggs to study how proteins cause disease.
 
Erika Eiser from the University of Cambridge and colleagues looked at how proteins in egg whites altered during this preservation process. The Chinese method involves wrapping raw eggs in an alkaline paste of lime, clay, salt, ash and tea and storing these so-called century eggs for several months. Eiser modified the method by incubating a boiled egg in a strong alkaline sodium hydroxide-salt solution for up to 26 days.

More: http://www.rsc.org/Publishing/ChemScience/Volume/2009/07/good_egg.asp