The melamine-contaminated pet food ingredients imported from China were actually wheat flour disguised to look like wheat gluten and rice protein concentrate, the Food and Drug Administration has revealed.
Although labeled as wheat gluten or rice protein concentrate by two Chinese firms, the products were in fact wheat flour, according to David Acheson, M.D., assistant commissioner for food protection with the FDA.
The addition of melamine could have been used to make the flour appear more protein-rich and less starchy, thus mimicking a high-protein product, such as wheat gluten, Acheson speculated.
“Now, there is a plausible hypothesis as to why this would be done rather than taking the trouble to extract the wheat gluten and wash away the starch, you simply grind up the wheat, put it all together and then artificially create the appearance of it being high in protein by adding a high-nitrogen containing compound such as melamine,” Acheson said.
The U.S. investigators have been in China for about a week, and are expected to return home sometime next week.
“The FDA considers this product to be mislabeled … and we're considering possible enforcement options,” he said.
The FDA made the discovery during forensic analysis.