Bacterial biofilms less likely on electropolished steel.

When the news came out that stainless steel can harbor bacterial biofilms there was much concern, especially regarding bacterial cross-contamination in poultry when poultry is processed, and bacteria from carcasses attach to wet steel surfaces on processing equipment. When the bacteria accumulate, they develop an increasingly complex matrix by attaching to each other and forming a bacterial film that stubbornly resists normal washing.

USDA/ARS researchers (Poultry Processing and Meat Quality Research Unit, Russell Agricultural Research Center, 950 College Station Rd., Athens, GA) found that surface finishing treatments, such as polishing, sandblasting and grinding, reduced buildup of bacterial biofilms. But electropolishing seemed to work the best.

Electropolishing involves placing steel in an acid bath, then running an electric current through the solution. The process may change the electrical charge on the metal. Bacteria are negatively charged, and the charge on a given surface can affect how well they attach to it. The findings are important to the poultry industry because of the fast-paced production. Some evisceration machines can process 90 to 140 birds a minute. It's important if electropolishing can prevent the cross-contamination of bacteria between birds and the buildup of bacteria over time.

Researchers next plan to explore how and where various bacterial species develop biofilms in processing plants. They'll also explore new chemical pre-treatments that could be used to prevent biofilms.

Further information. Judy Arnold; phone: [phone]; fax: [phone].