07.dec.06
USA Today
Elizabeth Weise
Taco Bell pulled green onions from all of its approximately 5,800
restaurants nationwide Wednesday after preliminary tests linked the
three-state outbreak of E. coli O157:H7 to scallions, company officials
said.
The outbreak of the potentially deadly form of E. coli has been tracked
to Taco Bell restaurants in New Jersey, New York and Pennsylvania. It
has sickened more than 60 people and sent nine people to the hospital.
One 11-year-old boy is in stable condition with kidney damage.
The Food Safety Network has records of nine cases of food-borne illness
outbreaks associated with green onions since 1994, says Douglas Powell,
professor of food safety at Kansas State University in Manhattan. These
latest cases are the first in which the onions were contaminated with
E. coli. Previous outbreaks have involved salmonella and hepatitis A.
A message released to the media was cited as saying that a first round of tests on three samples of green onions from the company's supplies were found to be positive for E. coli O157:H7 by an independent testing laboratory
McLane Co., which distributes food to the region's Taco Bells, said
federal investigators plan to test green onions, regular onions,
cilantro, tomatoes and lettuce from its southern New Jersey warehouse.
Most fast-food companies prepare their ingredients at central
locations. Michael Doyle of the University of Georgia Center for Food Safety was cited as saying that in Taco Bell's case, that includes shipping precooked ground
beef, adding, "They cook their beef very well."
Barry Swanson, a professor of food science and nutrition at Washington
State University, was cited as saying that other ingredients, such as cheese, green onions, olives and others, would most likely be processed at a centralized location and then shipped to chain restaurants within a given geographical area.
Fresh produce such as green onions or lettuce would be harvested, washed at a field station, then shipped to a nearby distribution center, Swanson says. From there it would likely be washed again in slightly chlorinated water and shipped to a packing plant.
At the packing plant it would be chopped into pieces and possibly
dipped in a diluted solution of ascorbic and citric acid to retard
browning. These are basically vitamin C and lemon juice, Swanson says.
They would then be packed into large plastic bags containing several
pounds of onions and shipped, chilled, to the restaurants.
"We'd like to think it's used within 24 to 48 hours at the restaurant
but it depends on how far they are from where they're going," Swanson
says.
The story notes that California farmers breathed a sigh of relief at word that the outbreak might be in green onions, because in November and December almost all green onions used in the USA are imported from Mexico.
Mexican green onions have been implicated in a food-borne illness outbreak before, though it was hepatitis A and not E. coli O157:H7. That outbreak, at Chi-Chi's restaurants in western Pennsylvania in 2003, killed four people and sickened more than 600.