%0 Journal Article %T The Effect of Umami Stimulation on Salivary Secretion Rate and Duration %A Eri Sambuichi %A Rumi Nishimura %A Shiho Morishita %A Shigeru Watanabe %J Health %P 52-59 %@ 1949-5005 %D 2024 %I Scientific Research Publishing %R 10.4236/health.2024.161005 %X Purpose: Umami reportedly promotes salivation. We aimed to investigate the effects of taste stimuli on slow and fast salivary secretion in humans using umami, sweet, and sour stimuli. Methods: Eight healthy women participated between 14:00 and 15:00, taking the circadian rhythm of salivary secretion into account. The types and concentrations of the taste solutions were glutamic acid (1.7 ¡Á 10&minus;3 M), inosinic acid (9.8 ¡Á 10&minus;3 M), and guanylic acid (9.8 ¡Á 10&minus;3 M) for umami stimulation, citric acid (6.5 ¡Á 10&minus;3 M) for acidity stimulation, and sucrose (1.6 ¡Á 10&minus;2 M) for sweetness stimulation. First, the unstimulated salivary flow rate was measured. Then, 3 ml of a flavor solution was dropped under the tongue using a syringe. The saliva was expelled into an aluminum cup every minute and weighed. The first minute¡¯s value minus 3 ml flavor solution was the stimulated salivary secretion rate produced by each flavor. The time-to-return to the initial unstimulated salivary flow rate was the duration of the stimulated saliva secretion rate. Results: The mean unstimulated salivary flow rate across participants was 0.64 ¡À 0.25 ml/min (range: 0.23 - 1.03 ml/min). The highest amount of saliva was induced by citric acid. There were significant differences between citric acid and the other flavor solutions (p < 0.05 for glutamic acid, inosinic acid, and sucrose; p < 0.01 for guanylic acid). There were no significant differences in duration of salivation between the flavor solutions. When the participants were divided into slow (0.45 ¡À 0.16 ml/min) and fast groups (0.83 ¡À 0.15 ml/min) based on their median resting salivary secretion rate, there were no significant differences between the two groups in the amount of saliva secreted at 1 minute after stimulation and the duration of the salivary secretion rate. Conclusion: Umami stimulation was effective in slowing salivary secretion and sustaining salivary secretion after stimulation. %K Salivary Secretion %K Umami Flavor %K Oral Health %K Stimulated Salivary Secretion %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=130639