For
some dropped foods, the five-second rule is about five seconds too long. Wet
foods, such as watermelon, slurp up floor germs almost immediately, according
to new research reported via
Science News.
Robyn
Miranda and Donald Schaffner of Rutgers University in New Brunswick, N.J.,
tested gummy candy, watermelon and buttered and unbuttered bread by dropping
morsels onto various surfaces coated with Enterobacter
aerogenes bacteria. Food was left on each surface — stainless steel, ceramic
tile, wood and carpet — for time periods ranging from less than a second to
five minutes. Afterward, the researchers measured the amount of E. aerogenes on the food, harmless
bacteria that share attachment characteristics with stomach-turning Salmonella.
As
expected, longer contact times generally meant more bacteria on the food. But
the transfer depended on other factors, too. Carpet, for instance, was less
likely to transfer germs than the other surfaces. Gummy candies, particularly
those on carpet, stayed relatively clean. But juicy watermelon quickly picked
up lots of bacteria from all surfaces in less than a second. These
complexities, the authors write, mean that the five-second rule is probably a
rule worth dropping.
See:
Posted by Dr. Tim Sandle