Abstract
The mechanisms of gelatinization and retrogradation in Katakuri (Erythronium Japonicum DECNE) starch were investigated by differential scanning calorimetry (DSC). Potato and edible canna starches were also used in order to compare the difference in thermal properties of Katakuri starch. The gelatinization and retrogradation of starch-water systems with different in water contents (Wc) and thermal histories were measured by DSC. Non-freezing water content (Wnf), which was strongly restricted by starch molecules and which was not freezed until-150°C, was calculated from the enthalpies (ΔH) of phase transition of sorbed water and Wc. It was found that Wnf increased with increasing Wc and leveled off at Wc more than 6.0 g/g. The gelatinization temperatures (Tα) changed in the order of Katakuri < Potato < Canna. While, the enthalpies of gelatinization (ΔHα) and the amount of Wnf changed in the order of Katakuri > Canna > Potato. These results suggest that Katakuri starch molecules have bulky structure compared with other starches of Potato and Canna.
