Swallowing dynamics of burdock treated with a chelating agent in patients with dysphagia.

Food modification is a common approach for patients with dysphagia. Treating vegetables with a chelating agent adjusts the hardness of food without altering its visual appearance. The current study aimed to evaluate the swallowing dynamics of burdock treated with a chelating agent (Chelate) compared with texture-modified soft burdock (SoB) and hard burdock (HaB) products in patients with dysphagia. Additionally, we investigated saliva secretion and physical properties of foods after chewing in healthy participants. We examined a total of 141 patients and 10 healthy participants. Swallowing function of patients was evaluated using videoendoscopy. In patients, Chelate left less pharyngeal residue compared with SoB and HaB, whereas the initiation and movement of swallowing, swallowing safety, and oral residue did not differ among the three foods. In healthy participants, the stimulated saliva volume during chewing for Chelate was higher than that for SoB, and was equivalent to that for HaB. The bolus properties of Chelate after chewing exhibited higher water content than other foods. Chelate had lower cohesiveness than SoB and tended to be softer than HaB. We speculate that Chelate shows better efficacy of swallowing in patients with dysphagia because of saliva secretion and physical properties of the food bolus after chewing.