Cross-linking affecting properties and in-vitro digestibility of starch-sucrose ester complexes

This study investigated the effects of cross-linking on the characteristics and in-vitro digestibility of starch-sucrose ester (SE) complexes. To achieve this, corn starch (CS) was cross-linked with various concentrations of sodium trimetaphosphate /sodium tripolyphosphate (5 %, 10 %, and 15 %). Subsequently, cross-linked starches (CLS) were complexed with SE through hydrothermal treatment. X-ray diffraction analysis revealed that V-type amylose-lipid complexes formed by the interaction between CS and SE. The resultant CS-SE complex significantly reduced CS digestibility, increasing its resistant starch (RS) content from 10.19 % to 22.71 %. The cross-linking modification did not alter the crystalline pattern of the CS-SE complex. Several CLS-SE complexes demonstrated higher enzymatic resistance compared to the CS-SE complex. The CLS10-SE complex exhibited the highest RS content of 39.37 % when the cross-linking agent concentration was 10 %. This phenomenon may be attributable to the cross-linking reaction having enhanced the interaction between starch molecular chains, reducing the solubility and swelling power, thereby hindering the accessibility of starch chains to digestive enzymes. These findings indicate that cross-linking modification is a practical approach to improving the anti-digestion performance of starch-lipid complexes.