The method will eliminate the protein content of added products and thus help find if toxic chemicals such as melamine have been mixed with the milk products.
The method, recommended for food producers and regulators across the country, will separate melamine and other crude compounds that contain nitrogen from the real protein before analyzing the content, according to Hou Caiyun, a food testing expert who led the research team.
The ratio of melamine, if it has been mixed with milk, can be calculated indirectly in the process, said Hou.
Food producers and quality supervisors have been determining the protein content in food products by also testing the nitrogen content, a method developed by Danish chemist Johan Kjeldahl in 1883.
But recently, scientists found that the Kjeldahl method does not distinguish melamine and other false nitrogen compounds from real protein.
The white, talc-like chemical melamine can be mixed with animal feed, and milk and other food products to falsely raise the protein content.
Using this to their advantage and ignoring the health threat it could cause, some manufacturers mixed melamine with milk products causing 54,000 infants to fall ill.
Four of these infants died, prompting the government to swing into action and crack down on milk sellers, as well as officials.
According to Hou, the new method announced by the ministry uses a chemical to distinguish real protein from other nitrogen-containing compounds and can be conducted through common laboratory equipment.
Moreover, the test costs far less than the exorbitant high performance liquid chromatography (HPLC) method, used till now to detect melamine in milk, Hou added.
Though it (the method) is not compulsory, it will enhance the standard of food additives, too. I hope it can raise the bar and stop some manufacturers from cutting corners to raise their profit, she said.
Hou said that the HPLC method, used specifically to detect melamine in fresh milk, should be resorted to in emergency cases.