November 1, 2006

E-beam reduces E. coli in ground beef, says ARS

Low levels of irradiation could reduce pathogen levels, including the potentially deadly E. coli in carcasses used for ground beef, researchers said.

A low dose, low penetration electron beam (E-beam) irradiation penetrating 15 millimetres below the surface of a carcass could reduce pathogens, Agricultural Research Service (ARS) scientists found at the Roman L Hruska Meat Animal Research Centre in the US.

Though pathogens were most prevalent on the surface of a carcass, a thorough mixing of ground beef increased the risk of sub-surface contamination.

Therefore, penetrating meat with E-beams instead of the usual methods of washing the carcasses' surface could be more effective in reducing pathogens.

A low dose could do so without affecting the odour or flavour when it was used to make stir fry or ground beef. High doses, on the other hand, penetrated further, killing more bacteria, but not without impairing the taste and smell.

There has been increased awareness about food-borne pathogens following the much hyped E. coli outbreak in 1993. The US beef industry spent more than US$750 million over the last decade to ensure safety in this regard.

Cattle could host E. coli without harm. Pathogens tended to gather on cowhides, and could cause problem if the meat was contaminated during hide removal, according to ARS. Killing pathogens in hides before removal also proved effective in reducing the risk of carcass contamination.

Irradiation exposed food to a low level of ionising radiation to kill bacteria, yeasts, parasites, and other micro organisms, which if left untreated, could cause food spoilage and illness.