Formulation and processing of gruels made from local ingredients, thin enough to flow by gravity in enteral tube feeding

Rheological characterisation of gruels made from some bio-based ingredients commonly used in food products

The present study was aimed to determine the impact of processing (dehulling or germination) on the structure and rheological behaviour of gruels made from sorghum, soybean and sesame. A rotational viscometer was used to determine the rheological parameters of gruels from these materials. Compared to each raw material, the processing presented a significant effect on the viscosity of the gruels. The power law model was better described the rheological behaviour of the gruels. All gruels were time-dependent fluids, except for germinated sorghum-based gruels. Most of them were thixotropic shear-thinning fluids, only germinated sorghum-based gruels are non-thixotropic shear-thinning fluids and those from dehulled soybean exhibited anti-thixotropic behaviour. The apparent viscosity of gruels decreased with temperature, fitting an Arrhenius relationship, with the activation energy ranging from 5973 to 27,674 J/mol. The rheological behaviour of these foods will helps to understand the behaviour of any products based on their mixture.