Decreasing Sterilization Time of Oil Palm Bunch with Direct Steaming Using Vacuum Pump

Abstract

This study investigated the reduction of sterilization time in direct whole bunch palm fruit sterilization using a vacuum pump. The research was divided into three methods: (1) a study of water boiling in a sterilizer to determine optimal conditions, (2) The Hybrid system involves opening valves to allow steam to naturally displace air. This process is optimized by starting air venting before reaching 100°C or 90°C., and (3) a study of palm fruit sterilization using a vacuum pump. In the first phase, water boiling tests were conducted under both vacuum and atmospheric conditions. By boiling 20 kg of water to a pressure of 2.5 bar, it was found that the -0.1 bar vacuum condition resulted in the shortest boiling time and the lowest energy consumption. Compared to the conventional method, this condition reduced boiling time by 47.91% and saved 28.22% in energy costs. These findings indicate that the -0.1 bar vacuum condition is a promising approach for further studies in palm fruit sterilization. In the second phase, palm fruit sterilization tests were conducted using vacuum pressures of -0.1. Approximately 200 kg of palm fruit bunches and 20 kg of water were used in each test, with the mixture sterilized to 2.5 bar and held for 30 minutes. Results showed that the vacuum system significantly reduced sterilization time and costs. The -0.1 bar vacuum condition was particularly effective. Moreover, the quality of the crude palm oil produced under all conditions met the acceptable standards, with an oil yield exceeding 18% based on fresh fruit bunch weight. Quality parameters such as free fatty acid, deterioration of bleachability index, peroxide value, and iodine value were within the established limits.