The surface microstructure and cross-section of pullulan films with
and without the addition of SBE were examined under a scanning electron
microscope (SEM) (type FEI, Quanta 200, Japan). Observations and
micrographs were made in Low Vacuum mode (LV mode) by using an
LFD detector, at an accelerating voltage of 30 kV. Before the measurement,
the films were conditioned in a desiccator at 25 ± 1 °C and RH
of 45 ± 5%.