Steady Shear Rheology and Fluid Mechanics of Four Semi‐Solid Foods

The steady shear rheology of four semi‐solid food materials (ketchup, mustard, apple sauce and tomato paste) was studied by generating and comparing flow data using cone and plate, parallel plate and capillary measurements over the shear rate range of 0.05–1600 see −1 . Super‐position of flow data was demonstrated and correlations obtained; using the power law, Bingham Plastic, Herschel‐Bulkley and Casson models were compared. In the low shear rate range (y = 0.05 – 1.0 set −1 ), the Bingham Plastic model and in the high shear rate range (y = 1.0 – 1600 sec −1 ), the Herschel‐Bulkley model were shown to be most successful. Comparison of average velocity data with mathematical predictions using the power law, Herschel‐Bulkley and Cas‐son models showed that the equation using the Herschel‐Bulkley model was best and should be used in the design of flow processes for the foods studied.