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time-intensity sensory evaluation

concept / concept-time-intensity-method

時間強度法（TI法）

Time-intensity sensory evaluation is a method for measuring the intensity of one sensation over time after a single exposure.

On this page (6 sections)
  1. Overview
  2. Sources for this overview (7)
  3. Topic hubs
  4. Follow the connections
  5. Related entries (10)
  6. Sensory (4)
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Reading the bitterness

The time-intensity (TI) method is a sensory-evaluation technique that records the strength of one perceived sensation over time after a single stimulus. ASTM E1909, the standard guide for time-intensity evaluation, defines TI as measuring the intensity of one sensation over time after a single exposure. Specific methods such as TI sit within the more general sensory-evaluation framework of ISO 6658.

TI has also been used to characterize oral chemesthesis that must be followed from entry into the mouth until the sensation fades, such as the tingling of Sichuan pepper. The source says 『中国産の花椒9検体を対象にした研究では...SPU150,000を境に高群・低群に分けたところ、高SPU群の方がTIで測定した曲線下面積・最大強度・持続時間のいずれも大きかったと報告されている。』 (in translation: "In a study of 9 Chinese Sichuan pepper samples ... divided into high and low groups at SPU 150,000, the high-SPU group was reported to have greater TI-measured area under the curve, maximum intensity, and duration in every case."); the text then calls for wording matched to the actual 2-group design. Another study combining TI and TDS for baijiu of different aging periods reported a significant difference in stimulus release rate by TI: aged baijiu had a higher release rate and significantly smaller area under the curve and duration. A 1993 study of oral burning examined cinnamaldehyde, piperine, and capsaicin, showing that an unrelated group had applied TI to oral chemesthesis 20 years before the Sichuan pepper and baijiu studies.

TI is one way to capture how food perception changes over time, but it measures something different from temporal dominance of sensations (TDS), which asks respondents to select the most prominent sensation at each moment from several candidates. TI scores the intensity of one sensation continuously; TDS records the proportion selecting a sensation as most prominent, and the sensation selected as most prominent need not be the most intense.

One application of TI to bitterness itself measured bitterness of the tea-catechin dimer theasinensin A. In a human panel study by Zhang and colleagues (2023), participants held aqueous theasinensin A solutions at 200, 400, 600, 800, and 1000 μmol/L in the mouth for 10 seconds, spat them out, then recorded bitterness intensity every 10 seconds up to 240 seconds. Bitterness duration was reported to increase with concentration. The study addressed bitterness only, without linking it to sweetness or huigan (sweetness that spreads later).

Sources for this overview

  1. Standard Guide for Time-Intensity Evaluation of Sensory Attributes (ASTM E1909-13, reapproved 2017)

    ASTM International / 2017 / standard / abstract checked

    Checked for this overview: Used ASTM E1909's definition of TI to support the opening explanation.

  2. Sensory analysis — Methodology — General guidance (ISO 6658:2017)

    International Organization for Standardization / 2017 / standard / abstract checked

    Checked for this overview: Used ISO 6658 to support placement within the general sensory-evaluation framework.

  3. Evaluation of the pungency intensity and time-related aspects of Chinese Zanthoxylum bungeanum based on human sensation

    Zhang LL; et al. / 2018 / journal article / abstract checked

    Checked for this overview: Used the description of TI values for 9 Sichuan pepper samples corresponding to Scoville values.

  4. Sensory characterization of Baijiu pungency by combined time-intensity (TI) and temporal dominance of sensations (TDS)

    He Y; Chen S; Tang K; Qian M; Yu X; Xu Y / 2021 / journal article / abstract checked

    Checked for this overview: Used the significant differences in release rate and area under the curve for aged baijiu.

  5. Time-intensity evaluation of oral burn

    Cliff M; Heymann H / 1993 / journal article / abstract checked

    Checked for this overview: Used the 1993 oral-burning study as an application 20 years earlier.

  6. Linking Temporal Dominance of Sensations for Primary-Sensory and Multi-Sensory Attributes Using Canonical Correlation Analysis

    Shimaoka N; Okamoto S; Akiyama Y; Yamada Y / 2022 / journal article / full text checked

    Checked for this overview: Used the explanation that TI and TDS measure different things.

  7. Bitterness quantification and simulated taste mechanism of theasinensin A from tea

    Zhang J-Y; Cui H-C; Feng Z-H; Wang W-W; Zhao Y; Deng Y-L; Jiang H-Y; Yin J-F; Engelhardt UH / 2023 / journal article / full text checked

    Checked for this overview: Used the concentration and timing conditions of TI bitterness measurement for theasinensin A.

Follow the connections

temporal dominance of sensations →is not synonymous with→ time-intensity sensory evaluation

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 (4)

time-intensity sensory evaluation is documented in The ASTM E1909 standard guide, which sits within the general sensory-methodology framework of ISO 6658contextual

Scope: Standardized sensory-methodology documents

ASTM E1909 is the standard guide for time-intensity evaluation, and is defined as a method that measures, over time, the intensity of a single sensation following a single exposure.
Limitations: The scope has been confirmed. The full text is behind a paywall.
Source: Standard Guide for Time-Intensity Evaluation of Sensory Attributes (ASTM E1909-13, reapproved 2017) (ASTM International, 2017) · abstract checked
Context: ISO 6658 provides general guidance on selecting sensory tests and their statistical treatment, and individual methods such as TI are positioned within this framework.
Limitations: The scope has been confirmed verbatim from the standard's own text (the free preview). Which section actually covers TI (estimated to be section 5.4 onward) remains unconfirmed, as it falls outside the preview range (purchase required).
Source: Sensory analysis — Methodology — General guidance (ISO 6658:2017) (International Organization for Standardization, 2017) · abstract checked
Show dataconcept-time-intensity-method —is_documented_in→ "The ASTM E1909 standard guide, which sits within the general sensory-methodology framework of ISO 6658"
claim: clm-ti-method-standardized / type: sensory / updated: 2026-08-30
time-intensity sensory evaluation is used as A method for characterizing time-dependent oral chemesthetic sensations, such as the tingling sensation of Sichuan peppersupported

Scope: Human trained-panel studies on pungent/irritant spices

Note: 2026-08-31: Calibration downgrade from established to supported, because the supporting evidence does not derive from a full-text check. Can be re-upgraded after a full-text check.

9 Sichuan pepper samples were characterized using Scoville units, descriptive analysis, time-intensity (TI), and temporal dominance of sensations (TDS) across 7 oral sensations.
Limitations: Panel size is not stated in the abstract (unchanged). However, the abstract itself does state the comparison figures between the high and low groups for SPU and TI (AUC/Imax/Ttot), which had previously been missed in extraction. The full text (Methods/Results) has not been reached.
Source: Evaluation of the pungency intensity and time-related aspects of Chinese Zanthoxylum bungeanum based on human sensation (Zhang LL; et al., 2018) · abstract checked
A different research group applied the same combination of time-intensity and temporal-dominance-of-sensations methods to a different pungent/irritant material, characterizing the pungency of baijiu and its subqualities. In TI, a significant difference was found in the rate of release of pungency: aged baijiu had a higher release rate, with a significantly decreased area under the curve and duration. In TDS, the dominant subqualities differed — burning and numbness for young baijiu, versus burning, tingling, and dryness for aged baijiu.
Limitations: Panel size and scale details could not be obtained from the abstract. The full text has not been obtained (Elsevier). This shows that TI/TDS are used for chemesthetic attributes in general, and is not specific to Sichuan pepper.
Source: Sensory characterization of Baijiu pungency by combined time-intensity (TI) and temporal dominance of sensations (TDS) (He Y; Chen S; Tang K; Qian M; Yu X; Xu Y, 2021) · abstract checked
2-AFC, time-intensity, and TDS were applied to hydroxy-sanshool compounds dissolved in water-ethanol, sucrose, NaCl, and MSG. The detection threshold for pungency was suppressed in sucrose, while NaCl and MSG had no effect; the area under the pungency curve increased with NaCl and MSG, and decreased significantly in sucrose. TDS resolved the spatial and temporal movement, within the mouth, of tingling, astringency, vibration, and numbness, with significant differences found in maximum rate, peak time, and duration.
Limitations: The first author shares a surname with the first author of another 2018 source in this collection on the same compound class, so independence from existing evidence is limited. Panel size is not stated in the abstract; the full text has not been obtained.
Source: Pungency Evaluation of Hydroxyl-Sanshool Compounds After Dissolution in Taste Carriers Per Time-Related Characteristics (Zhang L; Shi B; Wang H; Zhao L; Chen Z, 2017) · abstract checked
Verbatim: "Temporal oral burn profiles for cinnamaldehyde, piperine and capsaicin were quantified using time-intensity (TI) parameters." Compared with cinnamaldehyde, capsaicin was 1.5 times, 2.0 times, and 3.0 times greater in time to maximum, plateau time, and total time, respectively. This shows that, 20 years earlier than the Sichuan pepper and baijiu studies, an already-unrelated group had applied TI to oral chemesthesis as early as 1993.
Limitations: The number of assessors is not stated in the abstract. It covers only burning/irritation and does not address tingling-type chemesthesis.
Source: Time-intensity evaluation of oral burn (Cliff M; Heymann H, 1993) · abstract checked
The TI results showed that in the high-SPU group (>150,000 SPU), AUC, maximum intensity (Imax), and duration (Ttot) were more than 13,482.91, 42.05, and 900 s respectively, whereas in the low-SPU group (<150,000 SPU) these were lower, at about 4,201.06, 16.61, and 700 s respectively. Verbatim: "TI results showed that the high area under the curve (AUC), high intensity of maximum (Imax) and long duration time (Ttot) in high SPU samples were more than 13,482.91, 42.05, and 900 s, respectively, while these values were as low as 4,201.06, 16.61, and 700 s, respectively, in the low SPU samples."
Limitations: Panel size and statistical-test details are not stated in the abstract. The full text (Methods/Results) has not been confirmed. The abstract was quoted verbatim, but the units and scale definitions of AUC/Imax/Ttot themselves can only be confirmed in the full text.
Source: Evaluation of the pungency intensity and time-related aspects of Chinese Zanthoxylum bungeanum based on human sensation (Zhang LL; et al., 2018) · abstract checked
Context: The Scoville Pungency Units (SPU) of the 9 samples ranged from 38,000 to 460,000. Verbatim: "The SPU of samples was determined as ranging from 38,000 to 460,000."
Limitations: Details of the SPU measurement method (dilution series, panel) are not stated in the abstract.
Source: Evaluation of the pungency intensity and time-related aspects of Chinese Zanthoxylum bungeanum based on human sensation (Zhang LL; et al., 2018) · abstract checked
Show dataconcept-time-intensity-method —is_used_as→ "A method for characterizing time-dependent oral chemesthetic sensations, such as the tingling sensation of Sichuan pepper"
claim: clm-ti-method-used-for-chemesthesis / type: sensory / updated: 2026-08-31
temporal dominance of sensations is not synonymous with time-intensity sensory evaluationsupported

Scope: The difference between two evaluation methods that follow from putting something in the mouth until the sensation fades

Note: Do not read the proportion of times a sensation was chosen as most prominent as the intensity of that sensation, its pleasantness or unpleasantness, or how long it continued at that intensity.

TDS is a method of choosing, from multiple candidates, the sensation most prominent at that moment, and measures something different from TI, which continuously scores the intensity of a single sensation.
Limitations: The sensation chosen as most prominent is not always the most intense sensation.
Source: Linking Temporal Dominance of Sensations for Primary-Sensory and Multi-Sensory Attributes Using Canonical Correlation Analysis (Shimaoka N; Okamoto S; Akiyama Y; Yamada Y, 2022) · full text checked
Show dataconcept-temporal-dominance-of-sensations —is_not_synonymous_with→ concept-time-intensity-method
claim: clm-tds-not-time-intensity / type: sensory / updated: 2026-08-31
time-intensity sensory evaluation is used in: Bitterness measurement of the tea catechin dimer theasinensin A (concentrations 200, 400, 600, 800, and 1000 µmol/L; held in the mouth for 10 seconds then expectorated, with bitterness intensity recorded at 10-second intervals up to 240 seconds, at 25°C)supported

Scope: Human panel trial by Zhang et al. (2023)

Note: The source reports that the duration of bitterness lengthened as concentration increased. This study covers bitterness alone; there is no description connecting it to sweetness or huigan.

3 mL of sample solution was held in the mouth for 10 seconds and then expectorated, with bitterness intensity recorded every 10 seconds for up to 240 seconds. Concentrations of 200, 400, 600, 800, and 1000 µmol/L, at 25°C. The source reports that the duration of bitterness lengthened as concentration increased.
Limitations: Covers bitterness alone; there is no description connecting it to sweetness or huigan. The number of panelists could not be clearly confirmed in the text.
Source: Bitterness quantification and simulated taste mechanism of theasinensin A from tea (Zhang J-Y; Cui H-C; Feng Z-H; Wang W-W; Zhao Y; Deng Y-L; Jiang H-Y; Yin J-F; Engelhardt UH, 2023) · full text checked
Show dataconcept-time-intensity-method —is_used_in→ "Bitterness measurement of the tea catechin dimer theasinensin A (concentrations 200, 400, 600, 800, and 1000 µmol/L; held in the mouth for 10 seconds then expectorated, with bitterness intensity recorded at 10-second intervals up to 240 seconds, at 25°C)"
claim: clm-theasinensin-ti-bitterness-only / type: sensory / updated: 2026-09-02

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