Ultrasound to the agricultural rescue

Mar 19, 2012 7:27 pm
Clare Leschin-Hoar for Scientific American via CNet reports that the agricultural industry is looking to shoot ultrasound at vegetables to remove pathogens. "When applied to leafy greens, high-power ultrasound creates millions of tiny bubbles along a leaf's surface. As they burst at a rate of a thousand times a second, they provide high-energy shock waves that can get into the leaf's nooks and crannies to dislodge pathogens, which are then whisked away in the sanitized wash. (Earthbound is looking at citrus and peracetic acid-based sanitizers, both sanctioned for use with organic products.)," Leschin-Hoar wrote. "Mostly we're after E. coli O157:H7; norovirus that causes winter vomiting, and we'll continue working with salmonella and Listeria as well," says Robert Brackett, director of the Institute for Food Safety and Health (IFSH) at the Illinois Institute of Technology. The wine industry, Leschin-Hoar reports, has used ultrasound to clean oak barrels since 2006. From Wikipedia:
"Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults."
Read the full story at CNet.