bitter carry-over
concept / concept-bitter-carryover
苦味の持ち越し
Carryover in which a previously tasted stimulus affects the next bitter stimulus's peak intensity, onset, or time-integrated intensity. Direction depends on the compounds.
On this page (6 sections)
Reading the bitterness
Bitter carryover means a previously tasted stimulus changes perception of a subsequent bitter stimulus. A study of six bitter compounds—caffeine, denatonium, limonin, naringin, quinine, and sucrose octaacetate—matched concentrations within each participant to approximately the intensity of 1.18×10⁻5 M limonin and compared thirty-six presentation orders. For all six compounds, stimuli presented second had higher peak intensity, faster onset, and greater area under the time-intensity curve than when presented first. Three pairs were tested per session, with a two-stage rinse between pairs to remove the previous pair's effect and a water-only rinse between stimuli within a pair. This account is limited to the abstract.
In a separate sensory trial with actual drinks (a panel of sixteen), drinking roasted coffee first lowered subsequent bitterness ratings of chicory, whereas the reverse order (chicory first) did not change roasted-coffee bitterness ratings. Carryover was asymmetric for this pair.
A different pair in the same trial (chicory-based surrogate coffee and roasted coffee) showed similar asymmetry: roasted coffee first significantly lowered subsequent surrogate-coffee bitterness, but the reverse order did not significantly change roasted-coffee bitterness.
Sources for this overview
Effect of compound sequence on bitterness enhancement
Checked for this overview: Used the carryover and sensitization observed for all six compounds. / Used details of within-person intensity matching and rinse procedure.
Checked for this overview: Used asymmetry in which chicory bitterness fell only after roasted coffee. / Used the asymmetric carryover between surrogate coffee and roasted coffee.
Follow the connections
bitter carry-over →is documented as having→ bitterness →can be measured separately …→ astringency
Hypotheses and recipe candidates for this entry are on the Japanese page.
Structured claims — open a section to read each claim's confidence, evidence and limits
Sensory (3)
Scope: Order comparisons of 36 pairs from 6 bitter compounds, with intensity matched per individual
Note: Not the same magnitude across all pairs — both the sensitizing compound and the sensitized compound are compound-specific.
Show data
concept-bitter-carryover —can_enhance→ "The maximum intensity, rise rate, and area under the time-intensity curve of the subsequent bitter stimulus"Scope: Layer: food (human sensory trial). Sequential tasting and bitterness ratings of real-drink pairs of chicory, surrogate coffee, and roasted coffee (panel of 16).
Show data
concept-bitter-carryover —is_documented_as_having→ sensation-bitterScope: Layer: food (human sensory trial). Another pair in the same sequential-presentation study: surrogate coffee and roasted coffee.
Show data
concept-bitter-carryover —is_documented_as_having→ sensation-bitter