Acrylamide–asparagine relationship in baked/toasted wheat and rye breads

Abstract

Acrylamide in baked and toasted wheat and rye bread was studied in relation to levels of asparagine in flour, dough, bread and toasts. Asparagine was consumed during bread preparation resulting in reduced acrylamide content in the products. In wheat bread, 12% of the asparagine initially present in the flour (0.14 g kg−1) remained after yeast fermentation and baking; for rye bread, 82% of asparagine remained after sourdough fermentation and baking. Asparagine present in untoasted wheat bread had totally reacted after hard toasting. Toasted wheat and rye bread slices contained 11–161 and 27–205 µg kg−1 acrylamide, respectively, compared to untoasted wheat and rye bread with <5 and 7–23 µg kg−1 acrylamide, respectively. The dietary intake of acrylamide from bread (untoasted) of 2 µg day−1 is relatively low; however, acrylamide exposure from bread increases several fold for people eating toasted bread.