Formation of furan, alkylfurans and acrylamide during breakfast cereal manufacturing: Comparison of model experiments with industrial processes

Furan and alkylfurans as well as acrylamide are process contaminants formed during thermal treatment of food. Breakfast cereal production includes different processing steps like extrusion cooking, puffing or toasting. In this study the furan and acrylamide formation in model experiments as well as during industrial processes were investigated and compared. Highest levels of furans and acrylamide were observed in gun-puffed grain with up to 140 μg/kg furan, 82 μg/kg 2-methylfuran, 62 μg/kg 2-pentylfuran and 302 μg/kg acrylamide. For this process, a strong increase of process contaminant formation with decreasing product bulk weight was observed. The latter is achieved by raising puffing temperature and pressure during production. High formation of furans and acrylamide was also observed during toasting, with 52 μg/kg furan, 24 μg/kg 2-MF, 27 μg/kg 2-PF and 89 μg/kg acrylamide concentration as mean values immediately after toasting. During this step the highest temperature input is achieved and the product dried to lower the average moisture from 28 % to 3.4 %.

Clear differences between formation of furans and acrylamide were observed during extruded product manufacturing, where most of the furan formation occurred during extrusion cooking itself while acrylamide levels mostly increased during subsequent toasting and drying. Mean levels after extrusion cooking were 47 μg/kg furan, 17 μg/kg 2-MF, 36 μg/kg 2-PF and 96 μg/kg acrylamide, while after toasting and drying 52 μg/kg furan, 21 μg/kg 2-MF, 48 μg/kg 2-PF and 187 μg/kg acrylamide were recorded. Coating materials applied to breakfast cereals are no major source of furans. Instead, sugar coatings may lower furan and acrylamide levels in the final products due to the additional product weight.