Asparagine Concentration and Acrylamide Formation Potential in Wheat Flour as Affected by Sulfur Fertilization

Wheat flours grown at five different levels of sulfur fertilization and 15 commercial wheat, spelt wheat, and oat flours were analyzed for the content of sulfur, nitrogen, and free asparagine, the precursor of acrylamide. Flours were heated for 20 min at 170°C and analyzed for their content of acrylamide and 3-aminopropionamide, the key intermediate in acrylamide formation. The results demonstrated that the content of free asparagine in the unheated flours, as well as the concentration of 3-aminopropionamide and acrylamide in the heated flours strongly increased when sulfur supply had been reduced from 150 to 30 mg per pot. In commercial flours low or moderate concentrations of free asparagine, 3-aminopropionamide, and acrylamide were found indicating sufficient sulfur supply. In conclusion, cereals should be sufficiently fertilized with sulfur during growth to avoid high concentrations of acrylamide in heat-processed cereal products.