Chlorinated paraffins as chlorine donors for the formation of 2- and 3-chloropropanediols in refined vegetable oils.

The knowledge of chloropropanediols (MCPD) fatty acid esters formation pathways is an important condition for these processing contaminants mitigation. This study aimed to assess the potential of a group of lipophilic environmental contaminants, polychlorinated alkanes, commonly known as chlorinated paraffins (CPs), to contribute to the formation of MCPD esters. Laboratory-scale model systems representing vegetable oils contaminated with both a technical mixture of short-chained CPs and individual short-chained CPs were designed and subjected to heat treatment (230 °C, 2 h) to simulate the deacidification and deodorisation processes. A substantial increase in MCPD content (up to 3.4 times the control levels) was observed in systems spiked with a technical mixture. MCPD formation seems to correlate very well with the concentration of CPs in these systems. Based on the generated data, we can conclude that the processing of vegetable oils contaminated with CPs might contribute to elevated concentrations of MCPD. • Model systems simulating heat treatment during vegetable oil refining were designed. • Chlorinated paraffins (CPs) may act as precursors of chloropropanediols (MCPDs). • 3-MCPDs levels increased up to 3.4 times with short-chained CPs (SCCPs) addition. • 3-MCPDs in heated oil strongly correlated with the amount of added SCCPs mixture. • Possible mechanisms of hydrogen chloride release from selected SCCPs were proposed. [ABSTRACT FROM AUTHOR]