Ultrasonics in Food Processing

Ultrasonics refers to sounds, really pressure waves, generally above the frequency that humans can hear, starting at 20 kiloHertz (20,000 cycles/sec). The energy of ultrasound is inversely proportional to the square of frequency, so "power" ultrasound used for processing is 15–40 kHz, while frequencies greater than 100 kHz are used for imaging, medical diagnostics, and other applications. Humans can hear 15 kHz and some can detect 20 kHz, so hearing protection and sound-absorbent enclosures may …