Evaluation of the effects of intermittent frying in French fries and frying oil on monochloropropanediols, glycidols and acrylamide

The present study aimed to examine how different oils (extra virgin olive oil (EVOO), refined olive oil, high oleic sunflower oil (HOSO), and refined sunflower oil (RSO)) and intermittent deep-frying could influence the levels of glycidols (GD), monochloropropanediols (MCPDs) and acrylamide (AA) in pre-fried French fries. Time and type of oil affected the content of MCPDs, GD, and AA. The migration of MCPDs and glycidols in French fries during the frying was confirmed, but a new formation was also noticed. Extra virgin olive oil showed the lowest MCPDs and GD content (3-MCPD: 0.016-0.27 mg/kg, 2-MCPD < limit of detection (LOD)-0.04 mg/kg, and GD: 0.05-0.14 mg/kg). The 22% of the samples analyzed showed an AA content higher than 500 mu g/kg (the limit recommended by the EFSA), 18% corresponded to samples deep-fried with EVOO, and 4% to samples deep-fried with RSO. Moreover, the lowest AA level was found when using HOSO (121.2-250.8 mg/kg). The overall analysis of these results suggests that HOSO could be used as a deep-frying oil, furnishing a good compromise between MCPD accumulation and AA formation.