The regulatory effect of homogeneous and spherical nanocrystal seeds on long-term retrogradation of corn starch

The addition of nanocrystal seeds to promote retrogradation is a key strategy for producing resistant starch, However, the underlying mechanism remains unclear. In this study, spherical nanocrystal seeds (102 nm) were prepared through combined ethanol precipitation and acid hydrolysis, and their effects on the retrogradation of gelatinized corn starch (CS) were investigated. During storage, the crystallinity of CS increased from 1.74% at Day 0 to 6.59% at Day 28. For samples with added nanocrystal seeds, CS crystallinity increased from 1.78% to 8.25%, indicating that nanocrystal seeds facilitated the development of long-range ordered structures. Notably, the addition of nanocrystal seeds also increased the starch recrystallization rate constant from 0.25 to 0.39, confirming accelerated starch retrogradation. Moreover, nanocrystal seeds promoted the formation of a cross-linked network morphology and improved the thermal stability of retrograded starch. In summary, these findings provide mechanistic insights into the role of nanocrystal seeds in accelerating starch retrogradation.