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 °C. The retrogradation properties were determined using four DSC characteristics: glass transition temperature (( {text{T}}_{text{g}}^{prime } )), ice melting enthalpy (ΔH_i), amylopectin melting enthalpy (?H_r) and degree of retrogradation (DR). The Gongju (GJ) starch showed the highest gelatinization enthalpy (?H_g) value, followed by Gwangyang (GY) and Hadong (HD). ( {text{T}}_{text{g}}^{prime } ) of all samples gradually increased with increasing storage time, while ?H_i decreased as the storage time increased. ?H_r of all samples significantly increased after 2 days of storage. DR, calculated based on ?H_g and ?H_r, showed a similar tendency with ?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 ( {text{T}}_{text{g}}^{prime } ), ?H_i, and ?H_r, respectively suggesting that each sample experienced different retrogradation kinetics in different region.