Abstract:

The effect of different water contents on the retrogradation of lotus seed starch was studied by differential
scanning calorimetry (DSC) and X-ray diffractometer (XRD). The experimental results indicated that water content was
a significant factor affecting the retrogradation of starch.and that the aging of starch was inhibited when the water content
was too high or too low. The lotus seed starch was most easily recrystallized with a water content of 70%, and the degree
of retrogradation was highest. The changes in molecular conformation parameters, water diffusion coefficient, and noncovalent
interaction of aging models with different water contents were analyzed using molecular dynamic (MD) simulation
method. It was shown that molecular structure of amylose with water content of 70% tended to be more orderly arranged
and had stronger non-covalent interaction. These observations could explain the mechanism of retrogradation of starch at the
microcosmic level.

Key words: lotus seed starch, water content, retrogradation, molecular dynamics (MD)