Effects of sucrose, isomalt and maltodextrin on microstructural, thermal, pasting and textural properties of wheat and cassava starch gel.

This study investigated the effect of different levels (4, 8 and 12%) of sucrose, isomalt and maltodextrin on the microstructural, water absorption, physico-chemical, thermal and textural characteristics of wheat and cassava starch gels, by scanning electron microscopy (SEM), rapid visco analysis (RVA), differential scanning calorimetry (DSC) and texture profile analysis. According to SEM analysis, cassava granules were more impressed than wheat starch in the presence of isomalt > sucrose > maltodextrin. Results showed that water absorption decreased when the amount of sucrose, isomalt and maltodextrin increased. In contrast, onset (To), peak (Tp) and conclusion (Tc) temperature, and enthalpy (ΔH) of wheat and cassava starch gels, increased as the level of addition increased. With increasing the sugar concentration, To, Tp, Tc and ΔH gel enhanced significantly relative to the native starch. The polyols had more remarkable effects on the thermal properties of cassava starch than wheat starch. The texture of wheat and cassava starch gels incorporated with polyol sugars had solid-like properties. The gelatinization of starch was delayed more by isomalt than sucrose and maltodextrin. Moreover, the combination of principal component analysis and cluster analysis proved to be a suitable statistical approach to highlight the effect of adding varying levels of polyols to starch.