X marks the spot.

A Canadian company says it has developed a new plastic food wrap that takes the guesswork out of leftovers by detecting the presence of common bacteria. Using diagnostic tests similar to those found in home pregnancy tests, Toxic Alert Inc., Mississauga, Ont., has impregnated ordinary plastic wrap with antibody-based sensors that detect the presence of E. coli, Salmonella and Listeria. According to the company, the process works by printing the diagnostic test -- similar to ink -- into the wrap and sealing it in a clear coating. When the wrap detects bacteria, a colored X materializes. No word yet on when the product will be available for commercial application.

Starving Salmonella.

Although testing is still in the early stages, researchers at California State Polytechnic University at Pomona have developed a spray they believe prevents E. coli and Salmonella from contaminating meat products. Incorporating activated lactoferrin -- a protein derived from cow's milk -- the spray detaches bacteria from meat, preventing organisms from binding to iron and starving them so they can't reproduce. According to researchers, the spray hads yielded encouraging results in labs and at a slaughterhouse at the university. In addition to E. coli and Salmonella, the spray was shown to work against 10 radiation-resistant bacteria.

First case of irradiated beef.

Food Technology Service Inc. began irradiating case-ready ground beef and frozen hamburger patties for Colorado Boxed Beef Co. in late February, marking the first approved use of irradiation for beef. Due to public concern about E. coli, "we wanted to add this extra measure of safety," said Steve Saterbo, co-owner of Colorado Boxed Beef. The company introduced its Next Generation brand of irradiated case-ready beef and frozen patties, as well as frozen chicken, in mid-March. Food Technology Service is reputedly the first irradiation company in North America dedicated specifically to the food industry. The company has been irradiating a number of products, including spices, produce, poultry and food packaging, since 1993.