THE INVENTION RELATES TO A PROCESS FOR THE SURFACE PASTEURIZATION OR SURFACE STERILIZATION OF PARTICULATE FOOD PRODUCTS. THE WATER UPTAKE AND QUALITATIVE CHANGES OF THE FOOD PRODUCTS ARE MINIMIZED AND THE PASTEURIZATION OR STERILIZATION CONDITIONS ARE OPTIMIZED IN THAT THE FOOD PRODUCTS ARE USED PREHEATED, WHEREIN THE PRODUCT TEMPERATURE IS SELECTED A FEW DEGREES BELOW THE EVAPORATION TEMPERATURE OF THE PASTEURIZATION OR STERILIZATION SYSTEM, IN THAT THE PREHEATING TEMPERATURE OF THE FOOD PRODUCTS IS SELECTED LOWER THAN THE SATURATED STEAM TEMPERATURE, PREFERABLY A FEW DEGREES BELOW THE SATURATED STEAM TEMPERATURE AT A PREDETERMINED PRESSURE, IN THAT THE TREATMENT IS PERFORMED IN A MOIST, AIR-FREE ATMOSPHERE, WHEREIN THE PASTEURIZATION IS CARRIED OUT AT TEMPERATURES BETWEEN 55 AND 99°C AT A LOW PASTEURIZATION PRESSURE, OR THE STERILIZATION IS CARRIED OUT AT TEMPERATURES BETWEEN 100°C AND 140°C AT A HIGHER STERILIZATION PRESSURE, IN THAT THE HEAT TREATMENT IS CARRIED OUT FOR 1 TO 30 MIN, AND IN THAT THE WATER OF CONDENSATION IS REMOVED FROM THE SURFACE OF THE FOOD PRODUCTS BY A SUBSEQUENT VACUUM DRYING AT A FURTHER REDUCED PRESSURE.