Amylose and amylopectin functionality during baking and cooling of bread prepared from flour of wheat containing unusual starches: A temperature-controlled time domain 1H NMR study.

Amylose (AM) and amylopectin (AP) functionality during bread making was unravelled with a temperature-controlled time domain proton nuclear magnetic resonance (TD 1H NMR) toolbox. Fermented doughs from wheat flour containing starches with atypical AP chain length distribution and/or AM to AP ratio, or supplemented with Bacillus stearothermophilus α-amylase (BStA) were analyzed in situ during baking and cooling. The gelatinization temperature of starch logically depended on AP crystal stability. It was lower when starch contained a higher portion of short AP branches and higher when starch had higher AP content. During cooling, the onset temperature and extent of AM crystallization were positively related to starch AM content. BStA use resulted in slightly weakened starch networks and increased the starch polymers' mobility at the end of baking. That proton distributions evolved in a way corresponding to starch characteristics supports the suggested interpretation of NMR profiles during baking and cooling.