Exploring Texture and Biomechanics of Food Oral Processing in Fork-Mashable Dishes for Patients with Mastication or Swallowing Impairments.

Texture-modified diets (TMDs) are a primary compensatory treatment for hospitalized older patients with swallowing and mastication disorders. Nevertheless, the lack of a protocol for evaluating their objective textural properties hampers their industrialization and optimal patient care. OBJECTIVES: This study aimed (a) to evaluate the textural properties (maximum force, cohesiveness, and adhesiveness) and biomechanics of food oral processing (mastication cycles, time, and frequency) of ten fork-mashable dishes (Texture E BDA/IDDSI level 6), (b) to explore the impact of oral processing on texture, and (c) to measure the properties of the ready-to-swallow bolus (RSB) in healthy adults. METHODS: The textural properties (maximum force, cohesiveness, and adhesiveness) of ten dishes were analyzed with a texture analyzer before and after oral processing (RSB) in five healthy adults (30 ± 3.9, 3 women). Surface electromyography was used to measure mastication cycles, time, and frequency. RESULTS: The pre-mastication Texture Profile Analysis (TPA)-averaged values of maximum force ranged from 0.65 to 2.73 N, cohesiveness was 0.49-0.87, and adhesiveness was 0.01-0.95 N·s. Masticatory Cycles (46.87-19.13 MC) and time (36.73-15.80 S) from whole samples to RSB greatly and significantly differed among dishes, although frequency did not (1.68-1.11 MC/T). Post-mastication RSB TPA-averaged values of maximum force ranged from 0.70 to 2.24 N; cohesiveness, 0.49-0.73; and adhesiveness, 0.01-1.14 N·s. CONCLUSIONS: Despite all dishes being classified by the same qualitative descriptor (BDA level E/IDDSI level 6), there was a large and significant variation in their textural properties (maximum force, cohesiveness, and adhesiveness) when measured in SI units. In addition, in healthy adults, the masticatory cycles and time to achieve RSB greatly differed, whereas masticatory frequency remained quite constant.

Measuring the Rheological and Textural Properties of Thick Purees Used to Manage Patients with Swallowing Disorders.

Texture-modified diets are the first-line compensatory strategy for older patients with swallowing and mastication disorders. However, the absence of a common protocol to assess textural properties inhibits their standardization and quality control and, thus, patient safety. This study aimed to (a) assess the rheological and textural properties of ten thick purees (Texture C, British Dietetic Association), (b) understand the effect of oral processing, and (c) measure the properties of the ready-to-swallow bolus after oral processing in healthy adults. Shear viscosity at 50 s-1 and 300 s-1 and textural properties (maximum force, cohesiveness, and adhesiveness) of boluses of ten thick purees were analyzed with a rheometer and a texture analyzer before and after oral processing (ready-to-swallow) in five healthy volunteers. Viscosity varied by 81.78% at 50 s-1 (900-4800 mPa·s) among purees before oral processing. Maximum force varied by 60% (0.47-1.2 N); cohesiveness, 18% (0.66-0.82), and adhesiveness, 32% (0.74-1.1 N·s). The high variability of viscosity was also present in ready-to-swallow boluses, 70.32% among purees. Oral processing significantly reduced viscosity in most purees (French omelet, zucchini omelet, turkey stew, red lentils, noodles, and hake fish) and also significantly reduced maximum force (7-36%) and adhesiveness (17-51%) but hardly affected cohesiveness (<5%). All thick purees met the qualitative textural descriptors for Level C texture. However, all ten purees showed significant differences in all parameters measured instrumentally and were affected differently by oral processing. This study demonstrates the need to use instrumental quality control using standardized protocols and SI units to narrow the variability and provide the optimal values for patients with dysphagia who require texture-modified diets.

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

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.