Rheological modelling, microstructure and physical stability of custard-like soy-based desserts enriched with guava pulp

Search for food products containing functional ingredients such as soy derivatives and pulp fruits has stimulated the development of new formulations of desserts. The aim of this study was to evaluate the influence of the addition of water-soluble soy extract, modified starch and guava pulp on the rheological parameters, microstructure, water-holding capacity (WHC), creaming index, pH and soluble solid content of creamy soy-based desserts. Rheologically, the samples were characterized as no time-dependent, shear-thinning weak gel-like systems. The physicochemical and rheological parameters evaluated varied in a wide range as a function of the soy, starch and guava pulp contents, with the soy extract content being the variable that most affected these properties. There was a link between the microscopic analysis and the WHC, and a strong correlation between WHC and the rheological parameter Q was observed.