Friday, June 08, 2007

It's 30 Seconds, Not Five!


Continuing in the spirit of not writing anything original ... here's a little proof that a post-secondary education in North America isn't in vain ...

Behold the newest reason for foodies to celebrate, as explained in South Florida's Sun-Sentinel yesterday:


Dropping a piece of food on the floor and then picking it up and dining on it is a germaphobe's nightmare.

Streptococcus. Staphylococcus. E.coli. Oh, my!

But how bad is it?

A college professor and her students are challenging the prevailing wisdom of the so-called five-second rule, which for generations has governed how long little morsels can remain on floors uncontaminated.

The window, the Connecticut team has concluded, really is 30 seconds.

"We wanted to look at a real-world situation," said Anne Bernhard, assistant professor of biology at Connecticut College in New London, noting the difference between her team's work and that of an earlier researcher.

In 2003, Jillian Clarke was a high school intern at the University of Illinois when she confirmed the five-second rule after painstakingly coating floor tiles with E.coli, then dropping gummy bears and cookie pieces onto them.

But as with all findings in science, there was room for challenge.

Most people, Bernhard said, do not smear their floors with E. coli.

And therein lies her "real-world" research. She and her two students, Molly Goettsche and Nicole Moin, chose the college's busy cafeteria as a test area.

Instead of gummy bears and cookie pieces, Bernhard and her students chose apple slices and Skittles.

"The students wanted two different types of food sources: a wet source and one that was a dry food source, to test any differences," Bernhard said.

"You would think that a wet food source would be more likely to attract bacteria very quickly."

Each food item was dropped in triplicate for specific intervals that ranged from 5 seconds to 5 minutes.

"We did this experiment in the main dining area and about 2,000 students traffic through that area," Moin said yesterday.

"So you'd think there would be a multitude of bacteria on the floor."

But in the first set of tests, in which moist apple slices were dropped, the students were stunned to find they had blown the 5-second rule to smithereens.

What they saw after 5 seconds were pristine morsels. It wasn't until the 1-minute interval that they found bacteria developing on the apple slices.

It took 5 minutes for organisms to colonize a Skittle.

The conclusion, Bernhard said, is that instead of a 5-second rule for moist foods that have fallen, the standard should be 30 seconds: As long as you eat a moist food within 30 seconds of its fall, you're very likely to be in a zone of safety.

For dry, less porous foods, she added, you might be safe even if you allow them to stay on the floor for 1 minute.

Each of the foods was picked up after its allotted time on the floor and placed in a petri dish.

Bernhard said the object was to see whether colonies of bacteria grew in the dish within 24 hours.

"I can say only one thing," added Moin, who is going to veterinary school in the fall.

"This is really testimony to the great housekeeping at our school."

Still an open question for any scientist willing to take the challenge is the longstanding "kiss it up to God" rule.

So when you see me pick up that half a cookie I dropped on the floor at work, know this: It's me exercising my democratic right not to waste good, germ-free food.

I am prepared to deal with the fact that I may lose friends after this.

No comments: