Characterization of Dysphagia Thickeners Using Texture Analysis-What Information Can Be Useful?

Abstract

Besides shear viscosity, other texture parameters (adhesiveness or cohesiveness) might be relevant for safe swallowing in people suffering from oropharyngeal dysphagia. Shear viscosity is assessed through protocols developed using a viscometer or a rheometer. In contrast, protocols and instruments (capillary break-up rheometer) to assess adhesiveness and cohesiveness are less common and much less developed. Other equipment such as texture analyzers can provide useful information on food properties. Here, we aimed to explore different texture analyzer settings (type of test, probe, and protocol) to characterize four commercial dysphagia thickeners at the shear viscosity levels recommended by manufacturers. Among the tests used (extrusion or penetration) with the different probes (disc, cone and shape holder, sphere, or cylinder), cone extrusion provided information about adhesivity, disc extrusion about sample cohesiveness, and sphere about penetration and sample elasticity. The test speeds used influenced the results, but only one speed is needed as the different speeds provided the same fluid information; for easiness, it is proposed to use 1 mm/s. Comparing the texture analyzer results with viscosity values obtained at different shears, the texture analyzer parameters reflected information that differ from shear viscosity. This information could be relevant for the therapeutic effect of thickening products and food characterization.

Keywords: dysphagia; texture analyzer; thickener.

Figure 1

Force–deformation curve of the four thickeners derived from the extrusion test with disc ((A): nectar, (B): pudding) and cone (C): nectar, (D): pudding) at 1 mm/s. Different colors indicate different thickeners: green—thickener (A), pink—thickener (B), red—thickener (C), and blue—thickener (D).

Figure 2

Force–deformation curve of the four thickeners derived from the penetration test with sphere probe (top) and cylinder probe (bottom) at speed of 1 mm s⁻¹ (Left: nectar; Right: pudding). Different colors indicated different thickeners: green—thickener (A), pink—thickener (B), red—thickener (C), and blue—thickener (D).

Figure 3

PCA plot of texture and rheological measurement for the four thickeners at two consistency levels: nectar and pudding. EC—extrusion with cone, ED—extrusion with disc, PC—penetration with cylinder, PS—penetration with the sphere. In blue color are the samples and in the grey boxes are the apparent viscosities at different shear rates (10, 50, and 300 s⁻¹).(Thickeners: A, B, C, D).