Effects of soluble dietary fibers on the viscosity property and digestion kinetics of corn starch digesta

Four soluble dietary fibers (SDFs) were fortified with corn starch (CS) at different concentrations to match the same viscosity equivalents. The mixtures were subjected to a simulated digestion procedure to study the effects of SDFs on viscosity properties and digestion kinetics of CS. Results showed that SDFs increased the hydration property and decreased the water mobility of digesta. During digestion process, SDFs increased the apparent viscosity of digesta to some extent, and showed significant difference to delay the decay of digesta viscosity (kv). The amylolysis inhibitory ability was similar when each SDF was present at the same viscosity equivalent, however, significant differences were found on the digestion rate constant of k2. Linear correlations between kv and k2 were established for 1 and 2 equivalent groups. These results demonstrated that SDFs could delay the digestion process as chemistry differences, which related to their ability on delaying the change of digesta viscosity.