Influence of xanthan gum and tapioca starch on the retrogradation and gelation of finger millet (Eleusine coracana L. Gaertner) starch pastes

Dynamic storage modulus, G', was used to monitor the primary retrogradation tendency of model paste systems involving finger millet starch (FMS)-tapioca and FMS-xanthan gum mixtures during cooling and curing for 48 h at 25C. Xanthan gum enhanced retrogradation during cooling and did not reduce retrogradation in cured pastes relative to control finger millet pastes. FMS-tapioca mixtures exhibited reduced retrogradation during cooling and curing. Mechanical spectra of FMS-tapioca pastes indicated extensive paste network development in hot pastes and proper gels in cooled and cured pastes. Zero shear viscosity values of FMS-tapioca mixtures at some ratios indicated enhanced viscosity over and above the sum effect of the individual component starches at the same concentration. Reduced retrogradation and network development in FMS-tapioca mixtures was attributed to some kind of a "functional energy." These results demonstrate the applicability of starch mixtures to improve functionality and confer physical stability in food products.