Low intensity ultrasonics in food technology

Ultrasonic applications can be classified into low intensify or high intens ify applications. The latter are used to modify a process or product with u ltrasonics, while in low intensity applications the process or product modi fies the ultrasonic signal, thus providing information about the product. L ow intensity ultrasonics in food technology can be used to monitor a proces s (liquid level, flowmeters) or to determine the quality of food products. Since ultrasonic techniques are rapid, non-destructive, easy to automate an d relatively inexpensive, the number of applications is rapidly growing in this field. Ultrasonics can also be considered for use in laboratory testin g devices to determine physical and chemical properties of foods. Ultrasoni cs has been used to determine texture, composition and physical state in li quid and solid foods. The commonly measured ultrasonic parameters are veloc ity, attenuation and frequency spectrum composition. Velocity is the parame ter used most since it is the simplest and most reliable measurement. This paper reviews the basic principles of ultrasonics, the most suitable techni ques for each type of application, the tasting devices needed to make measu rements and the most interesting applications.