Food comprises a very diverse range of materials, generally they are complex, very variable in composition and character, ultrasound is well suited to the study of food materials, thus help a lot in quality assurance in food industry. An ultrasonic foreign body detector prototype based on the ultrasound pulse/echo method was used in beverages for quality control. The prototype is composed of a single pulse/echo transducer, a water jet nozzle and an x-y table; window-moving technique is used as a signal processing method. The FBs are detected by comparison the pressure ratio values between the echo from the container outer surface (front face) and that from inner surface (back face). The object-oriented graphical programming language, LabVIEW 5.0, was used to control an ultrasonic scanning system composed of an ultrasound transducer, an x-y table and a computer for foreign body (FB) detection inside beverages packed in glass containers. (Abstract shortened by UMI.)