An Investigation of Starch/Surfactant Interactions Using Viscosimetry and Differential Scanning Calorimetry

Abstract

AbstractViscosity measurements at 60°C and differential scanning calorimetry were used to investigate the behaviour of starch/surfactant mixtures. Preparation temperature proved to dramatically modify the rheological effects observed with wheat starch and the amylose‐complexing emulsifiers but was a less important variable with the more hydrophilic detergent species examined. The latter also caused quite large viscosity enhancements with waxy maize starch, effects not observed, or expected, with the emulsifiers. When 0.2‐M sodium chloride was present, however, the derergents were found to behave like the emulsifiers. To account for these differences it is suggested that the detergent species are able to complex with amylopectin molecules as well as with amylose, unlike the emulsifiers which, as previously thought, only seem to complex with amylose. Calorimetry experiments did not give direct evidence, in terms of observable transitions, for the occurence of amylopectin/surfactant complexes with any of the examined surfactants. Analysis of the enthalpies associated with the several transitions observed however did provide substantial support for the suggested hypothesis.