Investigation of Test Foods for Videofluoroscopic Examination of Swallowing Complying with Criteria Classifications of New Foods for Special Dietary Use System
Foods for People with Difficulty Swallowing in accordance with the new Foods for Special Dietary Use System enacted in April 2009 are based on three levels of criteria classifications corresponding to severity according to physical property criteria consisting of hardness, adhesion and aggregation. On the other hand, since in-depth testing of individual cases using Videofluoroscopic examination of swallowing (VF) and the like becomes increasingly indispensible as the severity of the patient's condition increases, in the case the patient uses commercially available foods certified as "Foods for People with Difficulty Swallowing", it is necessary that the type of foods selected coincide with test results. With this in mind, a study was conducted of conditions for preparing VF test foods suitable for each level of the aforementioned criteria classifications for the purpose of achieving a correlation between clinical findings and commercially available foods consumed on a daily basis. [Methods] Test foods were prepared by using a commercially available gelling agent and thickener in liquid barium diluted to 50 w/v%. At that time, physical properties of the test foods were measured while changing the concentrations of gelling agent and thickener. Measurements were made using a creep meter, while hardness, adhesion and aggregation were calculated based on methods defined in the regulations for approval of indication of foods for special dietary use. [Results] The hardness of the prepared test foods demonstrated higher values at 10°C than at 20°C in all cases. The test foods were determined to be able to be prepared at gelling agent concentrations of 1.00 % and 1.75 % for approval level I, at gelling agent concentrations of 0.50 % and 2.25 % for approval level II, and at a thickener concentration of 1.00% and gelling agent concentration of 2.75% for approval level III at 10°C , and at gelling agent concentrations of 1.00% and 2.00% for approval level I, at gelling agent concentrations of 0.75% and 2.50% for approval level II, and at a thickener concentration of 1.50% and gelling agent concentration of 3.00% for approval level III at 20°C. [Conclusion] The use of the results of this study will enable the preparation of test foods that satisfy each approval level of "Foods for People with Difficulty Swallowing" according to the new Food for Special Dietary Use System in the clinical setting. This suggested that it will be possible to achieve agreement between VF test results and commercially available foods.