Crystalline, thermal and textural characteristics of starches isolated from chestnut (Castanea mollissima Bl.) seeds at different degrees of hardness

The crystalline, thermal and textural properties of chestnut starches (CSs I–V) at 0%, 25%, 50%, 75% and 100% degrees of hardening (DHs) were investigated in this work. CS I had a structure of C-type crystallinity. With the increase of DH, more B-type crystalline regions and amylose–lipid complexes were formed. The gelatinisation temperature of CS and melting temperature of amylose–lipid complexes were not significantly changed as DH increased. However, a significant (P < 0.05) increase of ΔH was observed for CS V. The texture analysis indicated that CS V had a lower firmness, adhesiveness and a higher cohesiveness than CS I. The correlation test confirmed the significant correlations between ΔHs of gelatinisation and melting of amylose–lipid complexes, firmness, adhesiveness, cohesiveness and DH. All the results indicated that degradation of CS should be one of important mechanisms for the hardening of chestnut, especially in the late period of hardening.