Retrogradation kinetics of chestnut starches cultivated in three regions of Korea

Retrogradation kinetics of chestnut starches from three different regions of Korea were investigated during storage at 4 A degrees C. The retrogradation properties were determined using four DSC characteristics: glass transition temperature (), ice melting enthalpy (Delta H-i), amylopectin melting enthalpy (a dagger H-r) and degree of retrogradation (DR). The Gongju (GJ) starch showed the highest gelatinization enthalpy (a dagger H-g) value, followed by Gwangyang (GY) and Hadong (HD). of all samples gradually increased with increasing storage time, while a dagger H-i decreased as the storage time increased. a dagger H-r of all samples significantly increased after 2 days of storage. DR, calculated based on a dagger H-g and a dagger H-r, showed a similar tendency with a dagger H-r. The retrogradation rates of three chestnut starches were analyzed using the Avrami equation, and the time constants (1/k) were obtained. GY, GJ and HD showed the fastest retrogradation rate in , a dagger H-i, and a dagger H-r, respectively suggesting that each sample experienced different retrogradation kinetics in different region.