Sources, classification, analytical detection, and mitigation strategies for palm oil contaminants

An overview of contaminant fingerprinting and traceability of crude palm oil products is introduced. The review focuses on process contaminants, mineral oil hydrocarbons, environmental contaminants, agricultural residues, and packaging/contact migrants. The formation mechanisms of 3-MCPD esters and GEs, with emphasis on the roles of chloride precursors, DAGs, FFAs, bleaching earth, deodorization temperature, residence time, and vacuum/steam conditions, are discussed. Analytical strategies are critically evaluated, including GC–MS, GC–MS/MS, LC–MS/MS, LC-GC-FID, GC×GC–MS, HPLC-FLD, ICP-MS, ICP-OES, AAS, and QuEChERS-based multi-residue methods, with emphasis on matrix effects, artefact formation, recovery, and method validation. The role of foodomics, chemical fingerprinting, lipidomics, metabolomics, spectroscopy, chemometrics, and DNA-based approaches in authenticating palm oil origin, detecting adulteration, and distinguishing crude, refined, recycled, blended, and contaminated oils is highlighted. Regulatory perspectives from EFSA, FDA, EU, Codex, JECFA, ASEAN, and Indonesia are integrated with mitigation strategies across plantation, harvesting, milling, transport, refining, post-refining, and packaging stages. Future priorities include integrated datasets, MOSH/MOAH source apportionment, standardized methods, ASEAN occurrence data, and mitigation approaches that preserve nutritional quality.