Impact of tongue-palate squeezing on texture perception, oral processing, and bolus properties in...

Texture critically drives food acceptance or rejection, with oral processing varying widely among individuals and influencing dynamic perception and bolus formation. Adaptive strategies like tongue-palate squeezing often replace chewing in populations with masticatory or swallowing challenges (e.g., tooth loss, sarcopenia, xerostomia), yet their impact on texture perception, muscle activity, and bolus properties remain poorly evaluated, particularly in comparison to traditional chewing. This study compared chewing versus squeezing effects on texture perception, processing parameters (oro-exposure, muscle activity, salivation), and bolus properties using mashed potato (MP) enriched with psyllium (MP-psyllium) or xanthan (MP-xanthan). Twenty-six participants processed samples via chewing or squeezing until they were ready to swallow. Sensory evaluation covered textural (hardness, stickiness, cohesion) and hedonic (taste, texture, overall liking) properties. Electromyography measured masticatory muscle activity and chewing duration. Boluses were collected for saliva and texture analysis. Squeezing increased MP-psyllium hardness ratings (by 26%) and reduced MP-xanthan cohesiveness (by 45%). It prolonged oro-sensory exposure (by 22-31%), halved masseter and temporalis activity, and decreased salivation during MP-xanthan processing. Liking remained moderate (∼6/9). Both strategies softened boluses, but squeezed versions were harder or less cohesive than chewed. Oral processing strategies differentially modulate perception via sensory feedback, ensuring viscoelastic boluses for swallowing. Squeezing highlights tongue tactile sensitivity and compensatory prolonged exposure. These findings underscore texture-modified diets tailored to individual oro-sensory strategies. Rehabilitation for patients with chewing and swallowing disorders should be tailored to their specific oro-sensory processing needs.