Sensory Testing: 관능 검사 세종대학교 식품공학과 김 용 휘

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

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

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

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

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

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

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)

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)

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”

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”

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”

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

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”

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

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

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

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)

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