THE PRESENT INVENTION DISCLOSES A METHOD OF STERILIZING BUNCHES OF FRUIT FROM OIL PALM USING PRESSURIZED STEAM IN A STERILIZER VESSEL (20) WHICH CREATES DIFFERENT PRESSURE IN DIFFERENT LOCATIONS WITHIN THE VESSEL. ACCORDINGLY, THE METHOD INVOLVES A PLURALITY OF SENSOR COMPONENTS (26, 62, 64) FOR SENSING THE STATE CONDITIONS AT THE TOP AND BOTTOM PORTIONS (58, 60) WITHIN THE VESSEL (20). A PROGRAM LOGIC CONTROL (30) ACT AS A CENTRAL PROCESSOR THAT RECEIVES PRESSURE DATA FROM THE PLURALITY OF SENSORS (26, 62, 64) AND CORRESPONDING TO THE STATE CONDITIONS AT DIFFERENT LOCATIONS FROM THE SENSOR COMPONENTS, AND MANIPULATING THE STEAM INLET AND STEAM OUTLET VALVES (32, 34, 36, 38, 40) IN RESPONSE TO THE SENSED STATE CONDITION. THE STEAM INLET AND STEAM OUTLET VALVES ARE MANIPULATED TO BE AT A POSITION, SAID POSITION INCLUDES FROM AN OPENING POSITION TO A CLOSED POSITION, WHEREIN THE STEAM INLET AND STEAM OUTLET VALVES ARE CORRESPONDINGLY MANIPULATED SUCH THAT THE STATE CONDITION AT THE TOP AND BOTTOM PORTIONS (58, 60) WITHIN THE VESSEL WOULD BE ADJUSTED IN ACCORDANCE TO THE SENSED STATE CONDITION, AND THAT THE STEAM INLET AND STEAM OUTLET VALVES ARE ADJUSTED TO ACHIEVE SUBSTANTIALLY THE MOST CONDUCIVE STATE OF DIFFERENT PRESSURE AT THE DIFFERENT TOP AND BOTTOM PORTIONS WITHIN THE VESSEL DURING THE HOLDING PERIOD OF THE STERILIZATION PROCESS. FIGURE 1
