According to a report in the Hong Kong Standard, Health alert after mainland fake eggs found, fake eggs have been surfaced in Fujian province. And they can cause mental retardation. Nice.
The realistic-looking fakes contain no protein. Instead, chemicals such as alum, sodium alginate, gelatin, calcium chloride and sodium benzoate are found in them. The "yolk" is dyed with tartrazine while the eggshell is made of calcium carbonate.
What amazes me is that anyone could construct a realistic-looking egg at a lower price than by keeping a chicken! But according to the report: "The fake eggs are easy to make and cost 1 to 5 HK cents, compared with 25 to 30 cents for real eggs." Budding counterfeiters might like to study (the undated posting) on Weird Asia News, China’s 10 Steps to Make a Fake Egg.
According to an earlier posting on hoax-slayer.com, the fake aggs story is a hoax. Just goes to show you can't believe everything you read on (myth busting) websites!
