salivary protein replenishment
concept / concept-salivary-protein-replenishment
唾液タンパク再補充
Salivary protein replenishment is a concept describing recovery of salivary protein amount and composition after an astringent stimulus. It is not treated by itself as a measure explaining all astringency perception.
On this page (7 sections)
Reading the bitterness
This describes how far salivary proteins return to their previous state after astringency. In a study using tannic acid or alum dissolved in water, a measure of this 「戻り方」 (in translation: "pattern of recovery") was inversely associated with astringency intensity, explaining 33% and 29% of differences between individuals. Higher values can be read as a tendency for proteins to recover sooner and astringency to be felt less strongly.
However, the explained individual differences were limited to 33% and 29%; the measure cannot predict astringency perception as a whole. In the same study, when a chocolate-like solid test food containing tannic acid or alum was used, the same salivary-protein measure did not predict astringency intensity. The relationship seen in aqueous samples cannot simply be extended to all foods.
In a trial of 60 healthy adults exposed orally to cranberry constituents, acidic proline-rich proteins in saliva (proteins that readily bind astringent substances) increased after 5 minutes and remained above baseline after 10 minutes. This tracked a change in saliva, not direct evidence that participants continued to perceive astringency for 10 minutes. In another study with repeated EGCG intake over two weeks, changes in perceived bitterness and salivary proteins did not correspond one to one, so bitter perception cannot be explained by salivary-protein replenishment alone.
Sources for this overview
Salivary protein levels as a predictor of perceived astringency in model systems and solid foods
Checked for this overview: Checked the inverse correlation between salivary-protein recovery and astringency and the approximately 30% explained variation. / Checked the limit that only about 30% of individual variation was explained. / Checked that astringency could not be predicted in the solid test food.
Checked for this overview: Checked salivary-protein change 10 minutes after cranberry-constituent intake.
Checked for this overview: Checked the lack of correspondence between bitterness and salivary-protein changes.
Follow the connections
astringency →is partly predicted by→ salivary protein replenishment
bitterness →is not fully explained by→ salivary protein replenishment
Structured claims — open a section to read each claim's confidence, evidence and limits
Sensory (2)
Scope: A study that evaluated samples of tannic acid or alum dissolved in water
Note: The individual differences explained by the degree to which salivary protein returned after stimulation were 33% and 29% — not a figure that explains all of how astringency is perceived.
Show data
sensation-astringent —is_partially_predicted_by→ concept-salivary-protein-replenishmentScope: Solid test food to which tannic acid or alum was added
Note: A relationship that held for samples dissolved in water cannot be carried over to all foods as is.
Show data
concept-salivary-protein-replenishment —does_not_predict→ "The astringency of the solid chocolate-like sample used in the same study"Mechanism and receptors (2)
Scope: A trial in which 60 healthy adults took cranberry extract or unsweetened juice into their mouths
Note: What was confirmed up to 10 minutes later was a change in salivary protein, not a result that the participant kept feeling astringency for 10 minutes.
Show data
concept-salivary-protein-replenishment —can_remain_changed_after→ "10 minutes after taking a cranberry-derived component into the mouth"Scope: Salivary protein measured in the study in which EGCG was taken repeatedly for 2 weeks
Note: The change in perceived bitterness intensity and the change in salivary protein did not correspond one to one.
Show data
sensation-bitter —is_not_fully_explained_by→ concept-salivary-protein-replenishment