Distribution of umami taste sensitivity at the three different measurement sites. Umami taste sensitivity was examined at the three different measurement sites: the anterior tongue, posterior tongue, and soft palate. The subjects comprised 102 young and 82 elderly healthy participants. The x-axis shows the concentrations of the aqueous monosodium glutamate (MSG) solutions (1 = 1 mM, 2 = 5 mM, 3 = 10 mM, 4 = 50 mM, 5 = 100 mM, and 6 = 200 mM). The y-axis indicates the number of participants who correctly recognized the presence of MSG at each concentration of MSG.