Key To E. Coli-Free Spinach May Be An Ultrasonic Spa Treatment
Salad producers haven't succeeded in banishing E. coli and other
dangerous microbes from fresh greens, though they've tried hard.
As we've reported before, it's a major challenge to both growers
and the environment. But one scientist thinks he's making
progress – with a spinach spa that zaps bad bugs with
ultrasound. Ultrasound is nothing more than sound moving at a
frequency too high for humans to hear. It's commonly used for
medical tests, including those adorably fuzzy photos of babies
in the womb. Turn up the intensity, though, and ultrasound can
pack enough power to destroy bacteria. Ultrasound is
increasingly used in food production, and has been used
successfully to decontaminate other fresh foods, including apple
juice. But using ultrasound on greens has had only mixed
success. "Leafy greens are difficult," says Hao Feng, an
associate professor of food engineering at the University of
Illinois who built the spinach spa. Zap a spinach leaf