Authentication technology may help track food contamination

One rotten head of spinach spoils the entire barrel. So say many in the agricultural industry these days, as spinach growers report a dwindling market for even the safest and most reputable of companies. Although the recent outbreak of E. coli is likely traceable to a single source, all will suffer until that source is identified. Easier said than done, however. Spinach looks the same everywhere, and because packagers often mix together product from many different growers, it is not sufficient to simply locate a contaminated bag and trace it backwards to its manufacturer. What is needed, many say, is an inexpensive way to identify the origins of the spinach itself. Glen Rock, Pennsylvania-based ARmark Authentication Technologies, a division of Adhesives Research, believes it has such a method.

Although the company shies away from the word nanotechnology for public relations reasons, its “track and trace” taggants, measured between 50-200 microns in diameter, foot the bill to a T (a human hair is 110 microns in diameter). Despite their impressively small size, each food grade taggant can contain up to 16 lines of text, including perhaps the name of the farmer who produced the spinach and the pick date (this means the tagging would have to be done at the earlist possible point in the distribution chain). A handheld microscope attached to a computer is used to read the data by comparing the image to a database of stored “fingerprints” — thereby speeding up authentication time. The taggants themselves can be either sprayed on to food in a water-based solution or contained in a light coating. According to ARmark general manager Jeff Robertson, a single head of spinach might contain as many as 1000 taggants, which is not very many when one considers that a single pound contains 6 billion of them.

-read more in this company news release; ARmark Web site