Friday, May 18, 2007

'Five-Second Rule' for Dropped Food More Like 30

Two Connecticut College student researchers have found that the "five-second rule" - which stipulates that dropped food will be safe to eat if it stays on the floor for fewer than five seconds - might better be known as the "30-second rule."

Connecticut College seniors and cell and molecular biology majors Molly Goettsche and Nicole Moin took two food samples - apple slices and Skittles candies - to the Connecticut College dining hall and snack bar. They dropped the foods onto the floors in both locations for five, 10, 30 and 60 second intervals, and also tested them after allowing five minutes to elapse. They then looked for any rogue bacteria that might have attached to the foods.

The researchers found no bacteria were present on the foods that had remained on the floor for five, 10 or 30 seconds. The apple slices did pick up bacteria after one minute, however, and the Skittles showed a bacterial presence after remaining on the floor for five minutes.

The results prove, according Goettsche and Moin, that you can wait at least 30 seconds to pick up wet foods and more than a minute to pick up dry foods before they become contaminated with bacteria.

"The five-second rule should probably be renamed," Goettsche said. "You actually have a little more time."

The research was conducted under the supervision of Anne Bernhard, assistant professor of biology at Connecticut College. Previous research on the rule, Moin said, was conducted by a University of Illinois researcher in 2003 and involved dropping food items directly onto e-coli contaminated tiles.

"That is not what is representative of what actually happens," Goettsche said. "We wanted to apply this to everyday life."

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