The composition of freeze-dried potato (Shimiimo) was studied in comparison with fresh raw potato. Shimiimo had starch content of about 56%, while the nitrogen content was lower than that of raw potato. Total dietary fiber of Shimiimo was about 30-40% more than raw potato, as well as having higher lignin content.
Differential scanning calorimetry (DSC) revealed that the onset temperature for gelatinization of Shimiimo was higher than that of raw potato.
The molecular weight distribution of water-soluble fraction of the starch indicated a fairly clear peak on the high-molecular-weight side for the freeze-dried samples. We could classify Frs. I, II and III, according to their iodine color reaction, raw potato indicating Frs. I, II and III, while shimiimo only indicated Frs. I and Frs. II.
It is apparent from the results that the composition of Shimiimo changed during the freeze-drying treatment.
