Pasteurizing or sterilizing

A method for pasteurizing or sterilizing a product in liquid form which includes a heat sensitive substance comprising:

• substantially atomizing the product in liquid form by admixing steam in a mixing chamber heated by the steam so as to kill microorganisms and produce a pasteurized or sterilized product wherein
• the product in liquid form has a solid content of at least 53 wt. %;
• the steam is introduced into the mixing chamber using a spray nozzle, at a steam pressure of between about 3 bar and 20 bar;
• the temperature in the mixing chamber is between about 120° C. and 250° C.;
• the residence time of the product in the mixing chamber is between about 0.2 msec and 20 msec;
• and
• the weight ratio between the product in liquid form and steam is between about 1.6 and 10;
• and
• drying the pasteurized or sterilized product into powder form.