Evaluation of heat damage, sugars, amylases and colour in breads from einkorn, durum and bread wheat flours

To limit nutritional losses and optimise bread processing, heat damage indices (furosine, glucosylisomaltol, hydroxymethylfurfural), sugars, alpha-amylase, beta-amylase and colour were monitored during bread manufacturing from refined flour of three einkorn, three bread and one durum wheat samples. The heat damage indices increased only during the baking step. Furosine was significantly lower' in einkorn (on average, 9.3 +/- 5.33 and 25.3 +/- 10.70 mg/100 g protein in crumb and crust, respectively) than in bread wheat (31.6 +/- 3.05 and 115.6 +/- 13.53) and durum wheat (36.2 +/- 2.82 and 165.0 +/- 3.17). Glucosylisomaltol and hydroxymethylfurfural were detected only in the crust, with lower levels in einkorn (on average, 2.3 +/- 1.78 and 10.0 +/- 7.79 mg/kg DM, respectively) than in bread wheat (13.1 +/- 5.57 and 42.8 +/- 10.64) and durum wheat (18.9 +/- 1.11 and 57.2 +/- 0.80). The different behaviour of einkorn was probably related to its moderate beta-amylase activity, and thus the low maltose content of its dough. Colour was correlated with heat damage, as einkorn breads were lighter than the others. The results show that einkorn bread undergoes lower heat damage than analogous products from durum and bread wheat, thus probably better preserving its nutritional value. (C) 2011 Elsevier Ltd. All rights reserved.