7. Ultrasonic Technology

Ultrasonic has proven its merit as one of the most promising sensing methods for food quality evaluation due to its non-destructive, noninvasive, precise, rapid, and on-line potential. Ultrasonic is mechanical wave at frequencies above 20 kHz propagating by vibration of the particles in the medium and penetrating through optically opaque materials to provide internal or surface information of physical attributes, such as texture and structure. Ultrasonic non-destructive testing is a way of characterizing materials by transmitting ultrasonic waves into a material, and investigating the characteristics of the transmitted and/or reflected ultrasonic waves. For the purpose of quality measurement of materials, low-intensity ultrasonic with the power level of up to 1 W/cm² has been used. The low-intensity ultrasonic doesn’t cause physical or chemical changes in the properties of the specimen when it transmits through the material. However, high-intensity ultrasonic of the power range above 1 W/cm² may produce physical/chemical disruption and alteration in the material through which the wave propagates. High-intensity ultrasonic is usually used in cleaning, promotion of chemical reactions, homogenization, etc