Laminarin modulates long-term retrogradation-related water migration behavior of different crystalline starches and...

This study investigated the effect of laminarin (LM) on the long-term retrogradation and digestibility of starches with different crystal types, including A-type corn starch (CS), B-type potato starch (PS), and C-type lotus seed starch (LS), with emphasis on elucidating the underlying water migration mechanisms. The results demonstrated that LM addition inhibited water migration in retrograded CS (CS-7d), which specifically manifested in an increase in the tightly bound water fraction and a decrease in the total free water fraction of CS-LM-7d blends. This water redistribution restricted the formation of ordered starch structures, consequently increasing the slowly digestible starch (SDS) content and reducing the resistant starch (RS) content during in vitro digestion. In contrast, LM exerted opposite effects on PS, promoting water migration through enhanced water diffusion as indicated by reduced tightly bound water and increased free water fractions. This shift in water distribution was associated with the formation of more ordered structures in PS-LM-7d blends, and these structural changes ultimately led to an increased RS content in the blends. For LS, LM modulated water migration in a concentration-dependent manner, as indicated by decreased bound water and increased total free water fractions. The elevated water mobility facilitated the development of ordered structures in LS-LM-7d blends, consequently leading to higher contents of both SDS and RS in LS-LM-7d blends. Collectively, these findings provide empirical evidence supporting the potential use of LM in modulating the functional properties of starch-based food products.