Esters of 3-monochloropropane-1,2-diol and glycidol: no formation by deep frying during large-scale production of potato crisps

Fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPDE) as well as 2,3-epoxy-1-propanol (glycidol, GE) can occur as undesirable foodborne toxicants in fats/oils and related products. Because of their significant toxicity, it is a worldwide aim to minimize levels of 3-MCPDE and GE, and several research programmes are currently trying to gain further understanding of their formation. Here we report on the non-formation of 3-MCPDE and GE during the deep frying of potato crisps in large-scale industrial production using high-oleic sunflower oils (HOSO). Samples of potato crisps and corresponding frying oils were taken in nine series at several frying time points and subsequently analysed by GC–MS. The analysed samples (crisps and frying oils) showed very low levels of both contaminants varying between 0.10 and 0.85 mg/kg fat for 3-MCPDE and between 0.09 (LOQ) and 0.91 mg/kg fat for GE. The results indicate no significant change of either 3-MCPDE or GE levels during frying. Thus, the endogenous formation of 3-MCPDE and GE during frying of potato crisps using HOSO and typical large-scale conditions can be excluded.