The Role of Starch in Shaping the Rheo-Mechanical Properties of Fat-in-Water Emulsions

Abstract

The DMA technique was used to conduct experiments on the rheo-mechanical properties of emulsified bovine fat meat products stabilised with potato starch. Starch gels with starch concentrations corresponding to the concentration of starch in water in the emulsions under analysis were used as control systems. The research showed that the rheo-mechanical properties of starch gels and starch–fat gels result from the conformational changes occurring within the structural elements of their spatial network. In starch gels, segments formed by complex associations of amylose chains are structural elements, whereas in starch–fat gels (emulsions) these are additionally amylose–fat complexes. Changes occurring during progressive retrogradation increase the degree of cross-linking in them. In starch gels, they are conditioned by the starch concentration, whereas in emulsions they are conditioned by the concentration of starch and the presence of fat. The parameters obtained by adjusting the Avrami equation to the data obtained with the DMA method enabled the determination of three forms of organisation of the dispersion structure of starch–fat systems. Each of these forms of structure organisation is conditioned by the concentration of starch in the emulsion system.