2026 Volume 30 Issue 1 Pages 24-31
Background: Videofluoroscopic swallowing examination (VF) is recognized as the gold standard for evaluating swallowing physiology. Although standardized VF samples have been established for liquids and semi-solids, an agreed preparation protocol for rice―the primary staple food in Japan―has not been defined. The powder-mixing method enables barium incorporation without altering grain morphology, yet evidence to determine an appropriate concentration range remains insufficient.
Objective: To clarify how barium concentration affects the textural and mixing characteristics of rice samples prepared for VF evaluation using the powder-mixing method and to propose a practical concentration range.
Methods: Cooked rice (100 g) was mixed with pre-hydrated barium sulfate to achieve concentrations of 15%, 20%, or 25% (w/w). Rice-based VF samples were maintained at 45℃ and evaluated using a texture analyzer for hardness, adhesiveness, and cohesiveness (n＝8 per group). Mixability was visually assessed based on grain uniformity, separation, and aggregation.
Results: One-way ANOVA demonstrated significant differences in hardness (p＝0.003), adhesiveness (p＜0.001), and cohesiveness (p＜0.001) among concentrations. For hardness, significant differences were observed among concentrations, and the 15% condition exhibited intermediate values between the 0% and 20–25% conditions. For adhesiveness, significant differences were observed between 0% and ≥15%, whereas no significant differences were found among the 15–25% conditions. For cohesiveness, significant differences were observed between 0% and 20–25%; however, no significant differences were found between 0% and 15% or among the 15–25% conditions. Mixability was most favorable at 15–20%, whereas the 25% condition resulted in grain scattering and early aggregation.
Conclusion: A barium concentration of 15–20% appears most practical for preparing rice-based VF samples using the powder-mixing method, with 15% offering the best balance of uniformity, workability, and reproducibility. These findings provide foundational evidence for the standardization of rice-based VF samples, supporting more consistent and clinically relevant swallowing assessments.
