Ultrasonic propagation and thermal changes during milk gelation processes

Abstract

An ultrasonic measurement technique for gelation monitoring of dairy products is presented in this work. An ultrasonic pulse is emitted and received after travelling through the milk during two different processes: rennet coagulation and yoghurt formation. Changes of the ultrasonic propagation parameters containing information about the milk gelation process are reported. The temperature changes during gelation were also measured and its influence over the ultrasonic propagation was evaluated. This non-invasive and real-time measurement technique appears as an interesting method for quality control in the dairy industry.