1. Sensory Testing:
관능 검사
세종대학교 식품공학과
김 용 휘

2. Sensory Evaluation (Analysis) ; 관능 검사
Human Response to Products (Services)
Perception : Difference / Acceptability
Major Factor - Psychology of Human (in past)
New Concepts : Sensory Modality
Feeling
Smelling
Tasting
Hearing etc.
Any Combination

3. In Flavor & Fragrance Industry:
As Science of Sensory Evaluation
Psychology / Statistics
Product Science
(Food Science / Cosmetic Chemistry)
Biology / Physics / Engineering
Ergonomics / Sociology / Humanity etc
But, Key components
Language & Communication

4. General Requirements for Sensory Testing
(관능검사의 기본 구성요소)
Sensory Testing : Results Variation
due to Bias & Sensitivity by Individuals
1. Environmental Control : Physical Conditions
2. Test Respondents
3. Samples of Materials

5. Physical Conditions (관능검사 장소)
Preventing Bias & Sensitivity
Location ; Control of Environmental Conditions
Accessibility & Freedom from Confusion
2. Laboratory Layout
Waiting Room
Testing Area: Actual Testing Area
Sample Preparation Area
Avoiding Distraction but, not Isolation
3. Odor Control
Air Temperature & Humidity Control System
Odor Adsorption system & Padding
4. Lighting : Illumination
Color vs. Appearance – Affecting response
5. General Comfort

6. Test Respondents (관능검사 평가자)
Selection of Test Respondents : Ability to Communicate
Analytical Tests : Difference & Description
Ability to discriminate
Ability to describe
Ability to quantify
*Selection : Screening
Using Representative tests on Representative materials
Large numbers candidates
but, not special experience or position
Not necessary for selection of “Hypersensitive” person

7. Test Respondents (관능검사 평가자)-cont.
Selection of Test Respondents : Ability to Communicate
Analytical Tests : Difference & Description
Ability to discriminate
Ability to describe
Ability to quantify
*Discriminative Ability
Discriminative test – Triangle Test
Variation in Ingredients / Processing
Storage / Weathering conditions
Product age etc.
Should be over 6-80% recognizable Difference

8. Test Respondents (관능검사 평가자)-cont.
Selection of Test Respondents : Ability to Communicate
Analytical Tests : Difference & Description
Ability to discriminate
Ability to describe
Ability to quantify
*Description / Score Characteristics (Attributes)
Rating scales & Repeating Test
Level of Significance – panel member skill
Common vs. Less Common
Name
Descriptions
Associate odor (least consideration)

9. Test Respondents (관능검사 평가자)-cont.
Selection of Test Respondents : Ability to Communicate
Analytical Tests : Difference & Description
Ability to discriminate
Ability to describe
Ability to quantify
*Number of Panel Members
Variability of products
Reproducibility of Judgment
Degree of Difference
Descriptive Panel : 4-10 (usually less than 25)

10. Test Respondents (관능검사 평가자)-cont.
Selection of Test Respondents : Ability to Communicate
2. Affective Tests : Preference & Acceptance
“Liking” – Reflecting consumer population
Elimination of allergic persons
Internal Workers ; Judgment by Bias
Panel Numbers : Representativeness (Large is Good?)
Panel Members – Variation is High
Precision in Attribute Choice
~20 Panel Members
“How to interpret results”

11. Test Respondents (관능검사 평가자)-cont.
Selection of Test Respondents : Ability to Communicate
2. Affective Tests : Preference & Acceptance
“Liking” – Reflecting consumer population
Elimination of allergic persons
Internal Workers ; Judgment by Bias
Effects of Respondents on Interpretation of Results
in small panel numbers – experimental errors
not “Preference”, But screening “Non-Preference”

12. Test Respondents (관능검사 평가자)-cont.
Respondent Orientation & Training
In order to
Familiarize respondents with Test Procedures
Improve respondent’s ability
Recognition & Identification of Attributes
Improve Respondent’s Sensitivity & Memory
Reproducibility
Analytical Tests
Descriptive Distinctions among products
Training Common Language
not for Preference or Acceptance Questions
Affective Tests
“New” – may generate “Bias”

13. Test Respondents (관능검사 평가자)-cont.
Motivation of Respondents
Motivation – sharing results etc.
Physiological Sensitivity of Respondents
prevent Adaptation, specially to “odor”
General rule:
1 hr after eating / excising
20 min waiting after smoking / eating / drinking
avoid oral stimulation – spice food
No perfume / cosmetics / lipstick etc.
20-30 sec interval for testing
if food testing ; may require salivation
rinsing w/ water before testing

14. Test Respondents (관능검사 평가자)-cont.
Psychological Control
Sensory testing : Measurement and Evaluation of stimuli
as “applied Psychology”
minimize psychological variables
Respondent’s response : as “total perception”
Cue – Obvious differences
Codes – marking w/ code w/o product development history
3 digit random numbers
Multiple codes
Experimenter – Respondent’s desire to please tester
“Neutrality”

15. Samples of Materials
Selection of samples to be tested
Sample – Representative to products / processes
Avoid a single batch product
2. Preparation of Samples
No foreign attributes – Consistency
General Factors
Difference Testing
Simplicity – Detecting only Difference
Preference Testing
Typical / Normal use
Testing w/ different recipes
Controlled “voluntary” Additions
Carrier – relevant factors
but, not necessary – Adjust
Transfer test – Direct contact w/ Appropriate time & conditions
Control samples w/ Appropriate time & conditions

16. Samples of Materials – cont.
3. Presentation of Samples
Presentation – Uniformity : evaluation of intrinsic factors
Quantity / Containers / Temperature
Applicator / Apparatus / Eating utensils
Amount of Samples : Sufficient for three time evaluation
“Partial” representation rather than “Whole”
Temperature / Humidity control – Normal comsuption
(in Perfume – critical to Humidity : Acceptance)
Elimination of Appearance & Other factors
Reduced “Eye” stimulation – “Caution”
Order of Presentation
“Time Error” of psychological experimentation
Sequence of Qualit

17. Samples of Materials – cont.
3. Presentation of Samples – cont.
Order of Presentation
“Time Error” of psychological experimentation
Sequence of Qualities of Products
“Contrast effect” / “Convergence Effect”
One sample before another
“Position Error”
Number of Samples : Prevent Fatigue / Adaptation
(Psychological / Physiological limit)
Acceptability : One type / class – 3-4 samples
Preference : Paired comparison – 3 pairs
Rank order : Maximum of 4-5 samples
(confusion / visual stimuli interference)
Expert panel : 2-6 /hour

18. Physiological & Psychological Factors
Physiological factors
Adaptation (sweet)
Cross-adaptation (insensitivity – sugar to other sweeteners)
Cross-potentiation (sensitivity – sure enhancing sweet)
Enhancement – Increased intensity (amyl alcohol to PEA)
Synergy – Sum of two components (MSG w/Nucleotides)
Suppression / Masking – decreased intensity
(Sweet to bitter / sour)

19. Physiological & Psychological Factors – cont.
Expectation Error : Given information (aged flavors)
Error of Habituation : Same response to small variation
Stimulus Error : Irrelevant criteria
Logical Error : “in mind” judgment – Darker is better
Halo Effect : Overall rating – high or low
Order of Presentation Effect
Contrast effect : Blended is better than simple
Group effect : Single vs. Together
Pattern effect : Presenter’s Behavior
Time error / Positional bias
Error of Central Tendency : Middle of scale due to fear
Mutual Suggestion : Other panelist’s actions
Lack of Motivation : “Have to” behavior
Capriciousness vs. Timidity : Extremes vs. narrow range