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.