TITLE:
The Effect of Umami Stimulation on Salivary Secretion Rate and Duration
AUTHORS:
Eri Sambuichi, Rumi Nishimura, Shiho Morishita, Shigeru Watanabe
KEYWORDS:
Salivary Secretion, Umami Flavor, Oral Health, Stimulated Salivary Secretion
JOURNAL NAME:
Health,
Vol.16 No.1,
January
23,
2024
ABSTRACT: 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 × 10−3 M), inosinic acid (9.8 × 10−3 M), and guanylic acid (9.8 × 10−3 M) for umami stimulation, citric acid (6.5 × 10−3 M) for acidity
stimulation, and sucrose (1.6 × 10−2 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 ± 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
Conclusion: Umami stimulation was effective
in slowing salivary secretion and sustaining salivary secretion after
stimulation.