Researchers debunk 'five-second rule'

It turns out that bacteria may transfer to food that has fallen on the floor no matter how fast you pick it up. Rutgers University researchers disproved the widely accepted notion that it's okay to scoop up food and eat it within a "safe" five-second window. Donald Schaffner, Rutgers professor and extension specialist in food science, found that moisture, the type of surface and contact time all contribute to cross-contamination. In some instances, the transfer begins in less than one second. The researchers tested four surfaces — stainless steel, ceramic tile, wood and carpet — and four different foods: watermelon, bread, bread and butter and gummy candy. They also looked at four different contact times: less than one second, five seconds, 30 seconds and 300 seconds. They used two media — tryptic soy broth or peptone buffer — to grow Enterobacter aerogenes, a non-pathogenic "cousin" of salmonella that occurs naturally in the human digestive system.