Inhibitory activity towards human α-amylase in cereal foods

Wheat flour and vital wheat gluten contain high levels of α-amylase inhibitors (AI), a potential trigger of non-celiac gluten or wheat sensitivity (NCGS). The aim of this study was to determine inhibitory activity towards α-amylase from human saliva in cereal foods. No AI activity was detected in commercial foods such as cake, cookie, cracker, muffin, pretzel or ready-to-eat (RTE) cereals, except one RTE cereal with minimally-cooked vital wheat gluten (IC50 = 418 μg mL−1). Commercial pan bread and earth-oven artisan bread had variable AI activity, from high (IC50 = 1100 μg mL−1) to non-detectable (10 000 μg mL−1). Little AI activity, from 3693 to 9732 μg mL−1, was detected in bread under-baked in the laboratory for 30 min at 190 °C and made without sugar, or with 6 g/100 g vital wheat gluten or 0.3 g/100 g emulsifiers (monoglycerides; SSL); there was no AI activity in bread baked at 225 °C. Very high AI activity was found in wheat flour dusting on bread crust, from 124 to 359 μg mL−1. If thoroughly-heated, cereal foods would be safe for individuals willing to limit exposure to wheat AI, except bread with much flour dusting and foods formulated with minimally-cooked vital wheat gluten.