Microorganisms are destroyed and enzymes can be inactivated in liquids, such as juices for example, by continuously flowing the liquid and continuously flowing pressurized dense CO2 along flow paths which are separated by membrane having minute pores at which the flows contact each other in a nondispersive manner. Pressures in the two flow paths are equalized and the dense CO2 flow is continuously recirculated without depressurization. Contact between the flows can be maximized by using a plurality of parallel hollow fiber porous membranes with one of the flows being directed into the hollow fibers and the other of the flows being directed along exterior surfaces of the fibers. The process does not adversely affect properties of the liquid, such as taste, aroma and nutritional content, as heating of the liquid to a high temperature is unnecessary.
