Molecular weight effects on the gelatin/maltodextrin gel

The aim of this work is to demonstrate that the phase behaviour of the gela tin/maltodextrin gel can be controlled by means of the molecular weight dis tribution of the polymeric constituents and the cooling rate. In doing so, the technique of small deformation dynamic oscillation was used to monitor the mechanical strength of the binary gels and their melting profiles upon subsequent heating. Introduction of high molecular weight fractions induced a transformation from weakened deswelled gels to reinforced composite gels . The phase inversion point from gelatin to maltodextrin continuous gels wa s manipulated by decreasing the length of molecular chains of the protein a nd/or increasing that of the polysaccharide. The formation of maltodextrin continuous structures was further assisted by quenching the binary solution s from high temperature as opposed to slow cooling. For a given concentrati on of gelatin, it was possible to reduce to a third the amount of maltodext rin required for phase inversion in the mixture. (C) 1999 Elsevier Science Ltd. All rights reserved.