Processing factors of pesticide residues in cereal grain fractions

This study examined the distribution of 37 pesticide residues in different cereal grains (rye, wheat, oat, and barley) and their fractions, including flour, bran, and feed bran. The grains used in the study were sprayed in the field before processing to provide a more accurate representation of the fate of pesticide residues in these fractions. Pesticides were extracted using the QuEChERS method and analyzed by GC-MS/MS and LC-MS/MS. The highest concentrations of pesticide residues were generally observed in the bran fraction. The proportions of the total amount of pesticide in the bran was estimated to be 44%–83%, 31–82%, 29–80%, and 18–44% for oat, barley, wheat and rye, respectively. The results of the study were interpreted with a focus on lipid content and structure of the cereal grains. For each type of cereal grain, processing factors (PFs) were determined for the following fractions: whole grain to flour, whole grain to bran, and whole grain to feed bran. The average PFs from whole grain to flour were 0.14 for wheat, 0.25 for rye, 0.54 for barley, and 0.58 for oat. Similarly, the average PFs from whole grain to bran were 2.6 for wheat, 2.49 for rye, 1.68 for barley, and 1.52 for oat. The average PFs from whole grain to feed bran were 1.58 for wheat, 1.07 for rye, 0.69 for barley, and 1.7 for oat.