Workers who process animal carcasses might soon use a laser scanner to identify contaminated meat. Researchers at the Department of Agriculture and Iowa State University in Ames have devised a technology that exploits the unique fluorescent properties of digested plant matter in feces. Under the laser, the surface of a carcass lights up if it's tainted with feces, which can carry dangerous bacteria.
Currently, each meat inspector in a packing plant visually examines hundreds of carcasses per hour. Contaminated sections are cut away and discarded. However, visual inspection can't always distinguish harmless blemishes from spots of fecal matter.
To assist inspectors, Jacob W. Petrich of Iowa State and his colleagues built a device that shines blue or green laser light at a spot on a carcass and measures how much light comes back at various wavelengths.