Newly developed umami taste sensitivity test using filter paper disk test. Monosodium glutamate was used as an umami taste solution. Filter paper of 5-mm diameter was soaked with a taste-inducing chemical solution and placed on specific areas of the tongue and oral cavity using tweezers. The subjects were exposed to six different concentrations of umami solution: 1, 5, 10, 50, 100, and 200 mM. The lowest concentration at which the patient could detect and recognize the taste was defined as the recognition threshold.