The Effect Moisture Residue in Oil Palm Fruits with Microwave Technique: Quantifying the Significant Factor of Residual Moisture as the Process Parameter for Commercial Sterilization

— Drying sterilization (hot air and microwave heating) in oil palm mill is one of the alternative solutions. On the one hand, most of the previous studies are mainly focus on the power and exposure time in order to find the optimal condition for commercial-scale, but those conditions are possibly impractical when the batch size or physical properties of oil palm fruits change. Since the power and time represent the energy that put into the system during sterilization, the removing weight of oil palm fruits as equivalent to moisture content also directly relates to the amount of energy consumption. Therefore, in the present study, a controlling moisture residue was examined by the design of the experiment. The given result showed that 15% of moisture residue could be proper to control to achieve the standard requirements. The 15% of residual moisture was proved again by varying the treatment pathways of batch size and power of heating, the statistical analysis assured that there was no significant difference ( P ≥ 0.05) from the effect of different pathways when the oil palm fruits were treated at the same level and giving the positive results. All in all, the suitable value of moisture residue can be applied as the process parameter of drying sterilization oil palm fruits with a promising result of both physical properties and crude palm oil qualities.