Video Clip Observation During Chewing Influences Intraoral Manipulations, Bolus Properties, and Sensory Perception of Texture

This study investigated whether distraction during chewing affects oral processing and texture perception of mashed potato samples that differ in textural properties due to the addition of dietary hydrocolloids: pectin, which produces a softer product, and psyllium, which produces a harder one. Twenty-six participants chewed the samples both in a habitual manner (control condition) and while watching a video clip (distracted condition). Electromyography was employed to characterize chewing behavior, including chewing duration, rate, and muscle activity. Salivary flow and bolus characteristics were also assessed. Sensory ratings for hardness, homogeneity, moisture, cohesiveness, adhesiveness, and ease of swallowing were compared between the soft (pectin-containing) and hard (psyllium-containing) samples, as well as between oral processing conditions. During video observation, chewing duration was prolonged. The softer sample was chewed at a slower rate, primarily due to longer intervals between chewing strokes, whereas the chewing rate for the harder sample remained unchanged. Increased suprahyoid muscle activity suggested enhanced intraoral tongue manipulation. These changes in oral processing resulted in a bolus that was softer, less adhesive, and less viscous. Additionally, both salivary flow rate and mucin concentration were reduced during video observation. Changes in sensory perception were most pronounced for the softer sample, which was perceived as softer, more adhesive, and more cohesive under distraction. Overall, distraction during chewing alters intraoral manipulation, leading to boluses with modified properties and affecting texture perception. Further research is warranted to determine whether these findings may pose a risk for overeating starchy foods with a high glycemic load.