Melamine

When I first came to hear about the story of the adulterated baby formula by the Sanlu Group (三鹿集團), I was slightly incredulous: why did they choose melamine (三聚氰胺) ?

(As I told Vivian, one may add urea to push up the nitrogen content.)

Surely it is because of my ignorance in food chemistry. As I looked up the compound during my holiday, there were a number of interesting facts worth sharing.

In 1960's and 70's, melamine was often used as a source of non-protein nitrogen for feeding cows. In the stomach of ruminant animals, the compound is broken down by the bacteria, absorbed, and used for building blocks of protein.

The current problem seems to be the addition of this very compound to the milk (to fool the assay of protein content, which is part of the quality assurance procedure) rather than the feed of those cows. Non-ruminant animals - including human - could not utilize non-protein nitrogen. We could imagine infants have a permeable gut and the intact compound is absorbed, excreted, and precipitated in the urine.

Urea is in fact a commonly used non-protein nitrogen for cattle feed - usually in a resin with formaldehyde to control the release. As an additive for animal feed, ground urea-formaldehyde is sold in China with a romantic name "protein essence" (蛋白精).

Many of our people have a really wicked but poetic mind.