Effect of aqueous washing on chloride reduction and the storage stability on low-quality crude palm oil prior to refining

The presence of chloropropanols in edible oils is a significant food safety concern. Chloride in crude palm oil (CPO) is a precursor to the formation of 3-monochloropropane-1,2-diol esters (3-MCPDE) during refining; chloride retention during storage prior to refining remains under investigation. The study examined the impact of different washing treatments and storage duration on total chloride content (TCC), moisture and impurities (M&I), free fatty acid content (FFA), diacylglycerol (DAG), deterioration of bleachability index (DOBI), and iodine value (IV) of CPO. It was demonstrated that washing CPO with distilled water and 3% citric acid (DW+CA) resulted in the highest chloride reduction (37%) after one month of storage. A linear relationship was observed between TCC and FFA levels in the washed CPO, indicating that FFA is a strong predictor of chloride content. The DW+CA treatment also demonstrated a stabilizing effect on FFA levels, potentially mitigating oil deterioration during storage. These findings suggest that implementing DW+CA washing before CPO storage can effectively reduce chloride levels, enhancing the safety and quality of the oil and mitigating the risk of 3MCPDE formation during refining.