Ultrasonic spinning rheometry test on the rheology of gelled food for making better tasting desserts

Abstract

Rheological properties of gelled foods that may relate to the physics of the fluids in the swallowing process of complex food components are determined by ultrasonic spinning rheometry (USR) [T. Yoshida et al., “Efficacy assessments in ultrasonic spinning rheometry: Linear viscoelastic analysis on non-Newtonian fluids,” J. Rheol. 63, 503–517 (2019)]. Through rheological evaluations of thixotropic gelled food, the inaccuracies in standard rheometer data to capture the true-rheological property are discussed first with steady rotational and oscillatory tests; the inaccuracies arise from commonly existing problems that cannot be directly observed in standard rheometers (wall-slip, shear banding, shear localization, elastic instability, etc.). The results evaluated by standard rheometers would be related to the measurements being specific response, depending on the geometry of the measurement device. The USR test discussed here shows the potential to overcome these problems in the rheological evaluation of gelled foods and reflects the advantages offered by USR such as spatial, local, and oscillation cycle measurements; the results with the transient flow curve that has not previously been discussed can be usefully interpreted, and the stability of the food materials in the unsteady shear displayed is of great importance in understanding which rheology indicates the better texture.