Effect of pH, temperature and heating time on the formation of furan in sugar–glycine model systems

Furan (C4H4O) has been classified as a possible animal and human carcinogen by many international agencies. The formation of furan in three sugar–glycine models using glucose, fructose, and sucrose was investigated using headspace gas chromatography mass spectrometry method (HS-GC–MS) with various dual combinations of three important heat processing conditions, i.e. pH, temperature, and heating time. Results indicated that furan levels from sugar–glycine model systems during the thermal processing can be attributed to selective sugar types, pH, temperature, and heating time. In glucose–glycine and fructose–glycine system, the lowest furan level was detected in acid condition but in sucrose–glycine system furan formed significantly lower (P < 0.05) in acidic conditions the lowest furan level was found in alkaline conditions. The furan levels were observed to increase with heating time in all three model systems. Furthermore, less furan was generated in non-reducing sugar system (sucrose) than in reducing sugar system (glucose and fructose). Therefore, they demonstrate the possibility of limiting the formation of furan in heat processed foods by both the careful selection of carbohydrates (i.e. non-reducing sugars and reducing sugars) ingredients and appropriate processing conditions.