3-monochloropropane-1,2-diol esters (3-MCPDEs) in edible oils: formfation pathways, detection methods, and mitigation strategies

Abstract

3-Monochloropropane-1,2-diol esters (3-MCPDEs) are toxic contaminants formed during high-temperature refining of edible oils, especially in the deodorization stage. Upon ingestion, they can hydrolyze into 3-monochloro-2-propanediol (3-MCPD), a compound with known carcinogenic and reproductive toxicity. This review synthesizes recent findings on formation mechanisms, uniquely integrating quantum chemical studies to confirm direct nucleophilic substitution as the most energetically favorable pathway. A critical comparison of detection methods is also provided, contrasting established regulatory approaches with emerging methods. Furthermore, the review explicitly links mitigation strategies to their underlying mechanisms, demonstrating how interventions like precursor removal, process optimization, and antioxidant addition effectively disrupt specific formation pathways. This direct, mechanism-based synthesis offers a clearer framework for the targeted control of 3-MCPDEs, guiding both academic research and industrial practice.

Keywords: 3-Monochloropropane-1,2-diol esters (3-MCPDEs); Detection methods; Formation mechanism; Mitigation strategies; Oil refining.