The effect of different protein addition on the rheological, physical and sensory characteristics of extruded maize-based purees

Abstract

Over last years, consumers demand products that are easy to eat with health benefits. The use of extruded flours would be a good choice to reduce the preparation time. Moreover, high protein intakes would have a positive influence on the health of specific population groups. Therefore, this study aims to assess how the addition of vegetal (rice and pea) and animal (egg white and whey) proteins could influence the characteristics of purees prepared with extruded maize flour. Rheological behaviour, microstructure, viscosity, syneresis and sensory evaluation of purees were determined. The incorporation of vegetal proteins hardly modified the puree viscosity before and after heating, and reduced the syneresis after the freeze-thaw process. Animal proteins reduced the viscosity and G′–G′′ at 30ºC and increased them after heating, and also increased the syneresis after cooling and freezing. Finally, pea and egg white proteins hardly modified the overall acceptability while whey protein improved it.