UMIN-CTR Clinical Trial

Public title

Sensory testing of polyphenols in plant foods.

Acronym

Sensory testing of polyphenols in plant foods.

Scientific Title

Sensory testing of polyphenols in plant foods.

Scientific Title:Acronym

Sensory testing of polyphenols in plant foods.

Region

Japan

Condition

taste/olfactory

Classification by specialty

Not applicable

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

Polyphenols in plant foods are known as flavour compounds such as colour, bitterness and astringency, and 8,000 species have been identified to date. On the other hand, consumption of polyphenol-rich foods has been shown to reduce the risk of cardiovascular disease and activate brain function. We have confirmed that when certain polyphenol compounds are ingested by animals and humans, various functions such as stimulation of the circulation and improvement of metabolism occur immediately afterwards, and that these physiological changes are responses mediated by activation of brain function. In addition, compounds with particularly strong activity are generally considered to have a "strong astringency", but there are very few cases of scientific verification. Therefore, in this study, a sensory test will be carried out on the taste quality of polyphenols. In addition, some polyphenols are ingested orally by animals. As the effect of maintaining alertness has been confirmed, we will also investigate changes in mood after oral intake.

Basic objectives2

Others

Basic objectives -Others

Some polyphenols are ingested orally by animals. As the effect of maintaining alertness has been confirmed, we will also investigate changes in mood after oral intake.

Trial characteristics_1

Confirmatory

Trial characteristics_2

Pragmatic

Developmental phase

Not applicable

Primary outcomes

Taste

Key secondary outcomes

Mood

Study type

Interventional

Basic design

n-of-1

Randomization

Non-randomized

Randomization unit

Blinding

Single blind -participants are blinded

Control

Uncontrolled

Stratification

NO

Dynamic allocation

NO

Institution consideration

Institution is not considered as adjustment factor.

Blocking

NO

Concealment

No need to know

No. of arms

1

Purpose of intervention

Diagnosis

Type of intervention

Food

Interventions/Control_1

A polyphenol concentrate extracted from plant foods is diluted in three steps with commercially available mineral water and used as a test sample. The panelists hold the aqueous solution in their mouths for 10-20 seconds and then spit it out. They then answer the taste quality questionnaire. The testing schedule is to conduct the first test 60 minutes after the designated breakfast and the second test 1 hour after the designated lunch. Thirty minutes after the end of the one-course test, the panelists also answer a mood profile test (POMS; web version, manufactured by Kaneko Shobo Co., Ltd.).

Interventions/Control_2

Interventions/Control_3

Interventions/Control_4

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

20

years-old

<=

Age-upper limit

40

years-old

>=

Gender

Male and Female

Key inclusion criteria

Subjects are selected as follows from a pool of panelist candidates (target 25) who have been informed of the test and have given their consent. Candidate panelists hold a solution of caffeine (standard for bitterness) or alum (standard for astringency) diluted in three steps for 10-20 seconds and then spit it out. They then answer the taste quality questionnaire. We select 10 panelists who are highly sensitive to bitterness and astringency.

Key exclusion criteria

Panelists with low sensitivity to bitterness and astringency.

Target sample size

10

Name of lead principal investigator

1st name	Naomi
Middle name
Last name	Osakabe

Organization

Shibaura Institue of Technology

Division name

College of System Engineering and Science

Zip code

3378570

Address

Fukasaku 307, Minumaku, Saitama, Saitama

TEL

0487206031

Email

nao-osa@shibaura-it.ac.jp

Name of contact person

1st name	Naomi
Middle name
Last name	Osakabe

Organization

Bioscience and Engineering

Division name

Food & Nutrition Laboratory

Zip code

3378570

Address

Fukasaku 307, Minumaku, Saitama, Saitama

TEL

048-720-6031

Homepage URL

Email

nao-osa@shibaura-it.ac.jp

Institute

Shibaura Institue of Technology

Institute

Department

Personal name

Organization

Shibaura Institue of Technology

Organization

Division

Category of Funding Organization

Self funding

Nationality of Funding Organization

Co-sponsor

Name of secondary funder(s)

Organization

Shibaura Institue of Technology

Address

Toyosu 3-7-5, Kotoku, Tokyo

Tel

03-5859-7340

Email

ykodama@ow.shibaura-it.ac.jp

Secondary IDs

YES

Study ID_1

23-010

Org. issuing International ID_1

Shibaura Institute of Technology Biotechnology Research Ethics Review Committee

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

Date of disclosure of the study information

2023

Year

11

Month

21

Day

URL releasing protocol

https://pmc.ncbi.nlm.nih.gov/articles/PMC13115364/

Publication of results

Partially published

URL related to results and publications

https://pmc.ncbi.nlm.nih.gov/articles/PMC13115364/

Number of participants that the trial has enrolled

47

Results

After a four-day training course, young adults could tell the difference between bitter, astringent, and sour tastes. Four polyphenols were tested to see if they were acidic, bitter, or astringent, and if they could be described in detail using taste tests. The results showed that one polyphenol was acidic, one was bitter and astringent, and one did not show any sensory characteristics.

Results date posted

2026

Year

05

Month

24

Day

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

Before the experiment, written informed consent for voluntary participation and the oral administration of reference solutions and polyphenols was obtained from the candidates ;26 males and 23 females, aged 20 to 28 years. To standardize terminology and measurement scales, a glossary was developed based on the previous literature and utilized for the flavor profile analysis test. The intensity of each flavor attribute was evaluated using the QDA method. The sensory evaluation was conducted in three integrated phases: screening, training, and quantification. First, the 3-AFC method was utilized to determine individual taste recognition thresholds, ensuring panelist sensitivity. Second, FPA was performed during 21 sessions to establish a consensus on sensory terms and their definitions. Finally, QDA was employed to measure the intensity of each attribute for the four polyphenol samples. This sequential integration ensured that the quantitative data were based on verified sensory capabilities and a unified sensory language.

Participant flow

The screening process for panelist selection was conducted as follows, participants were asked to place their mouths on 10 mL of the solution for 10 s, then spit it out to identify the reference standard. Caffeine and PAS were used to represent bitterness and astringency, respectively, at concentrations of 0.1, 0.2, and 0.4 mg per mL. Participants assessed their sensitivity to various stimuli, including bitterness, astringency, sweetness, saltiness, acidity, umami, dryness, roughness, shrinkage, numbness, spiciness, and oiliness. Furthermore, participants were tasked with distinguishing between the three concentrations and evaluating the intensity of each sensation using a 100 mm Visual Analog Scale, ranging from 0 to 100.
The number of panelists was determined through a power analysis based on preliminary experimental results. Based on a priori power analysis using G power, the total sample size required to achieve a power of 0.80 was calculated to be 7.
As a result, seven subjects, 5 males and 2 females, aged 22 to 25 years, who successfully distinguished both caffeine and PAS at 0.4 mg per mL during a screening test were selected as panelists. The panelists underwent a training program focused on taste identification and the determination of recognition thresholds, following the method described by Otsubo et al. with slight modifications. This program, comprising the taste recognition threshold test and taste training, was conducted over four months, with sessions held on four consecutive days each month. Panel validation was assessed through longitudinal tracking of TRTT and score consistency. By the end of the training, the panel demonstrated a marked increase in sensitivity. Furthermore, panel consensus was verified by the convergence of descriptive scores during the 21 training sessions, ensuring that the participants met the proficiency requirements for an analytical sensory panel as defined by ISO guidelines ISO 8589,2007. The daily protocols were as follows,
Day 1, The TRTT was conducted using six concentrations of citric acid, 0.05, 0.1, 0.15, 0.2, 0.4, and 0.8 mg per mL, six concentrations of caffeine, 0.1, 0.15, 0.2, 0.3, 0.4, and 0.8 mg per mL, and five concentrations of PAS, 0.15, 0.2, 0.3, 0.4, and 0.8 mg per mL.
Days 2 and 3, Participants underwent TT, where they were repeatedly exposed to three concentration levels, the recognized threshold, one level above, and one level below,in a randomized order. This process continued until the subjects could accurately and consistently identify the tastes.
Day 4, Subjects evaluated the three flavors using the QDA method, following the same TRTT protocols as on Day 1.In addition to the three standard substances previously described, the panelists evaluated four types of polyphenols, quercetin hydrate, gallic acid, epigallocatechin gallate, and a PRF. Each was tested at concentrations of 0.2, 0.4, and 0.8 mg per mL. All sensory testing was performed in a dedicated sensory laboratory equipped with individual partitioned booths, in accordance with ISO 8589 standards. The environment was strictly controlled, the room temperature was maintained 24 degree, and the area was kept free from extraneous odors and noise to ensure maximum concentration. To eliminate visual bias and ensure the objectivity of the panelists, standardized white lighting was used throughout the sessions. Furthermore, to prevent interaction and mutual interference, panelists were physically separated by partitions, and samples were presented in a randomized order with three digit codes. This experimental setup ensured that each assessment was independent and free from psychological or environmental distractions. The evaluations were conducted three times daily two hours after breakfast, two hours after lunch, and two hours after the second session, over a seven day period in a randomized order. The trained panelists were instructed to rinse their mouths with 10 mL of three separate solutions, holding each in the mouth for 10 s before spitting it out. Participants were then tasked with identifying the sample that differed from the others using the 3AFC and rating the intensity of the sensation using the QDA method

Adverse events

Nothing in particular.

Outcome measures

sweetness Taste sensation stimulated by sugars such as sucrose and other substances such as saccharin
salty Taste caused by substances such as table salt
acidity Taste sensation stimulated by acids contained in citric fruits such as lemon,
bitterness Taste sensation associated with caffeine in a water solution,
umami Taste is caused by substances such as monosodium L-glutamate and sodium 5-inosinate.
astringency A combination of shrinking, puckering, drying, and roughening sensations in the mouth
dryness A dry mouthfeel that lacks moisture.
roughness Sensation of roughness in mouth
puckering Sensation of contraction, puckering in mouth
numbness Sensation of numbness in mouth
pungency Sensation is caused in the mouth by substances such as capsaicin in chili peppers.
oily Sensation of oily in mouth

Plan to share IPD

IPD sharing Plan description

Recruitment status

Preinitiation

Date of protocol fixation

2023

Year

07

Month

18

Day

Date of IRB

Anticipated trial start date

2023

Year

11

Month

25

Day

Last follow-up date

2024

Year

12

Month

30

Day

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

Other related information

Registered date

2023

Year

11

Month

21

Day

Last modified on

2026

Year

05

Month

24

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000058939