工业硫酸铜 泡制“毒皮蛋”

A new round of food safety checks is underway in China after reports emerged suggesting a number of egg-processing plants have been using potentially-toxic copper sulphate to help pickle lime-preserved duck eggs.

CRI's Li Dong has more details.

Additive Problems in Lime-preserved Eggs 

Generally, preserved eggs, a pungent appetizer usually served with pickled ginger or cooked in congee, become edible after duck eggs are preserved using an alkali, salt and clay mixture for some two months.

But with copper sulfate, the preservation stage will be halved. There are altogether more than 2,000 enterprises nationwide which produce thousand-year eggs.

This is a mature business, but Ma Meihu, deputy director of the Chinese Association of Animal Product Processing says the national standard for preserved eggs was created a long time ago and simply cannot keep up with today's market and technology.

"The current national standard was issued in 1988. That's more than 20 years ago. Plus, with the upgrading of the egg processing technique, it's necessary to make a new national standard to examine the manufacturing process."

Food grade copper sulphate can substitute lead oxide which is widely used in traditional preserved egg processing, creating lead frees final products. But some experts say the enterprises should use proved food grade additives rather than industrial grade additives, which pose uncertain risks.

Assistant researcher at the China National Center for Food Safety Risk Assessment Zhong Kai says examining only the final food products is not the best option for reducing the risks of food safety.

He adds that the focus of food inspections should be on the processing procedure rather than the final product.

"Inspection of the manufacturing process should be the core of food safety management. I agree with other experts when they claim that good food products are not the result of inspection processes but rather manufacturing. If all sections of the food manufacturing processes are under supervision, the risk to food safety will be minimal."

China has seen multiple food safety scandals in recent years.

Recent scandals involving adulterated mutton, lime-preserved eggs processed with copper sulphate, and ginger grown with highly toxic pesticides, have aggravated public concerns over food safety.

For CRI, I am Li Dong.