Noninvasive ultrasonic measurements in the food industry

Low-intensity ultrasonics frequently range at intensities lower than I W/cm(2) and at frequencies higher than 100 kHz. They are used in food industries for both process control and product assessment or control. Two kinds of techniques are used, through-transmission and pulse-echo. The most commonly used ultrasonic parameters are velocity and attenuation. The applications of low-intensity ultrasonics are encountered in all food industries mainly vegetables, dairy, and meat. When traveling through a medium, the ultrasound waves change their characteristics and the analysis of this change allows assessment of properties of the medium. Different properties of foods have been addressed in the past and have mostly been linked to texture (maturity, ripeness in cheese, melons, avocados, etc.), composition, or even sensory characteristics. Defect detection such as cracks in cheese or hollow hearts in potatoes has also been addressed.