In Vitro Digestibility, Pasting and Thermal Properties, and Structure of Cross-Linked Arenga pinnata (Wurmb.) Merr. Starch

Sodium trimetaphosphate (STMP) cross-linked Arenga pinnata starch (CLAPS) with different degrees of cross-linking (0-97.79%) are prepared and their structural characteristics and physicochemical properties are evaluated. Cross-linking does not significantly change APS granular structure, but seems to lower the intensity of Maltese cross. With the cross-linking degrees (CLD) increasing from 0.00% to 97.79%, the rapidly digestible starch (RDS) content of CLAPS is decreased from 66.50% to 16.34%, but the resistant starch (RS) content has the opposite trend and is increased from 29.87% to 82.77%. As the CLD increased, the solubility and swelling power of APS are significantly reduced from 10.24% and 16.52 g g(-1) to 1.02% and 4.60 g g(-1), respectively. Low CLD could increase viscosities of the APS, whereas high CLD significantly reduce the viscosities of the APS and the greater theCLD, the more obvious the reduction effect. Meanwhile, cross-linked APS exhibits a high conclusion temperature and lower gelatinization enthalpy (Delta H). With the CLD increasing, short molecular ordered structure of CLAPS exhibits increasing trends. These results indicate that crosslinking with STMP can significantly alter digestibility and improve thermal stability of APS, which would provide a theoretical basis for development of APS products and could be used in low glycemic index (GI) foods.