Microstructure of a freeze-dried aqueous solution of maltodextrin DE 12 (5 % w/w)

Sample preparation Maltodextrin (Glucidex 12D form Roquette, France) with a dextrose equivalent of DE = 10 - 14 (on average DE 12) was mixed with demineralized water, the solution having a solid fraction of 5 % (w/w). The solution was gently stirred with a magnetic stirrer at 300 rpm for 1 h at ambient temperature. The sample material was stored at 4 °C until usage in experiments. Freezing and lyophilization For the freeze-drying experiment, 120 µl of the prepared solution were filled into a specially designed freeze-drying stage (further information can be found in Hilmer et al. (2020)), resulting in cylindrical sample size with an diameter of approximately 7 mm and 5 mm height. The temperature of the sample material was at first lowered inside the stage with a rate of 6 K/min until 10 °C were reached. Subsequently a holding time of 10 min was applied. After that, the sample was frozen to −15 °C (again at a rate of 6 K/min), followed by a holding period of 30 min at that temperature. The lyophilization step was activaed afterwards by applying a nominal vacuum of 10 Pa (so the 10 are the set pressure in the pump, the pressure inside the stage was significantly higher). X-ray computed tomography The microstructure was captured after freeze-drying using the TESCAN DynaTOM (TESCAN XRE, Ghent, Belgium). This system captured the sample with around 3.9 µm voxel size with a beam voltage of 70 kV and time per 360° rotation of 30 min. Reconstruction of the CT-data was performed with Panthera software (TESCAN XRE, Ghent, Belgium). Data files The dataset includes 3 files, which are as follows: img@raw_res@1935x1935x1103_vxl@3.87592x3.87592x3.87592_uint16.raw:Contents: Unprocessed image data of the microstructure of the whole sample including sample holderResolution: 1935 × 1935 × 1103Voxel size: 3.87592 µm (in each dimension)Encoding: uint16 img@raw_ori@568x868x1_res@400x200x800_vxl@3.87592x3.87592x3.87592_uint16.raw:Contents: Cutout from previous raw imageOrigin: [568, 868,1]Resolution: 400 × 200 × 800 img@binarized_ori@568x868x1_res@400x200x800_vxl@3.87592x3.87592x3.87592_uint8.raw:Contents: Binarized version of the previous raw image