Ponencia presentada en el XIX Congreso Internacional de Acústica (ICA2007), Madrid, 2-7 Sep 2007.-- PACS: 43.35.-C.The use of power ultrasound together with supercritical CO2 is a non-conventional promising technique for extraction processes in food industries. Extraction of almond oil, adlay seed oil, pungent from ginger are good examples of the potential use of this novel technology. In fact, power ultrasound represents an efficient manner of producing agitation in the media enhancing mass transfer on supercritical fluids extraction processes. A prototype for the use of ultrasound in supercritical media is presented in this paper. Special attention has been given to the transducer and its behaviour as a function of power and time during operation. Specific software to control and monitoring the parameters involved in the process has been developed. This tool will allow the best conditions for the operation process to be selected.We are grateful for financial support from the National Research Project PETRI-PTR95- 075.OP.02.Peer reviewed