Oscillatory water sorption dynamics of bread crust

Step-wise and oscillatory gravimetric sorption experiments were used to study the equilibrium and dynamic water sorption behavior of bread crust. Water uptake kinetics is strongly related to crispness retention of composite products consisting of a dry crispy part and a more humid and soft part. We show that oscillatory sorption experiments of bread crusts could be very well described by a Fickian diffusion model. Many essential features, such as the shape of the oscillatory sorption curves, and the dependency of water sorption rates on time, time-interval between successive step-wise changes in relative humidity, and particle size are understood now to a great detail.

► Step-wise and oscillatory sorption experiments are performed on bread crust.
► Fickian diffusion model describes oscillatory sorption experiments very well.
► Essential features of oscillatory water sorption in bread understood to a great detail.
► Insights allow better prediction of the crispness of bread crusts.