Summary Principles of Sensory Science
Lecture 2: Selection and Training of Sensory Panels
- Chapter 3 – Principles of good practice; 3.5 Panellist consideration.
After the lecture the student is expected to:
- Know how to select assessors for sensory panels for different purposes
- Understand the role of the panel leader for the success of sensory projects
- Know different manners of attribute generation
- Be able to generate sensory attributes for the QDA in this course
- Understand and be able to explain how different methods of descriptive analysis require different
degrees of training
- Know and be able to apply the methods of consensus training and individual vocabularies
Why select sensory subjects?
→ Find all the nuances that can be detected e.g. intensity.
How to select sensory subjects?
→ Recruitment of analytical sensory panels (repeatable and precise):
- Internal or external
- Age 20-55 (senses are stable)
- Test about twice the number of subjects needed
- Announcement… media, canteen, class, etc.
→ Panel selection by questionnaire:
- Personality: Be able to work in a team; ”Cosmopolitan” preferences; Positive not over-
bearing; Good listener and communicator; Committed and flexible.
- Health: General good health condition; Documentation of any health restrictions
(medication, allergies, pregnancy, false teeth, …)
- Availability
→ Panel selection by tests for sensory ability
Example of a rapid taste
test is papers dipped in
different concentrations
to test if you taste the
basic taste.
Rapid odour test Sniffin’
sticks:
How to train sensory subjects?/ When is the panel trained enough?
→ General training: familiarisation with test protocols, discrimination tests, intensity scaling
→ Product specific training: describe what the different properties are, especially important for
descriptive analysis.
→ Attribute specific training: making concepts cognitive clear (=understandable) to the sensory panel
,Selection and training of subjects needed for descriptive, not for threshold and discrimination:
Check performance over time?
→ Monitoring of performance of analytical sensory panels
- Inter individual variation (between individuals)
- Intra individual variation (within individual)
- Sequential analysis – long-term performance
- Feedback on performance to individual or panel
What are the roles and personal characteristics of a panel leader?
→ Type of roles (depending on the method)
- Passive facilitator (e.g. QDA)
- Directive leader (e.g. Spectrum)
→Personal characteristics
- Non-judgemental/opinionated
- Sensitive and assertive, but diplomatic
- Leading panel discussions but active listener
- Recognises and guards against moderator bias
- Ability to motivate panel
Lecture 1: Descriptive Sensory Analysis
- Chapter 10 – Descriptive analysis
After the lecture the student is expected to:
- Know the principles of methods such as mapping, napping, Flash Profile and their field of application
What is descriptive sensory analysis?
- A method aiming to provide a quantitative measure of the sensory properties for a set of
products
- A number of different approaches
o Trademarks (QDA and Spectrum)
o Speed versus accuracy (accuracy not good with rapid methods; training panel for a
long time gives a food accuracy, find a lot of details)
o Relations to instrumental measures (perception of sourness and ph value in milk; if
correlated that replacement of sensory panel by instrument)
, Why using descriptive sensory analysis?
- Product reformulations
- New product development
- Quality control
o Acceptability to specified target
o Calibration of instrumental methods
- Brand mapping (e.g. identifying sensory niches)
- Consumer preference mapping
- Research
o Understanding relationships between product/process/production properties and
perceptible properties
What are the main differences between methods?
- Generation of sensory descriptors
- Degree of subject training
- Use of reference materials and scaling
What is the flavor profile method?
- Consensus method (4-6 judges; 2-3 weeks training)
- A qualitative descriptive method – no statistical analysis possible due to consensus scores
- Reference materials for discussing and defining
- Limited to flavour impressions
- Estimate intensity of flavour attributes (aroma, flavour, mouth feel and aftertaste). Expand
with - + ½ ↑ ↓
- Estimate intensity of overall amplitude (overall balance and blending of product):
What is the Quantitative Descriptive Analysis?
- Data from individual panel members (n=10-12) in sensory booths
- Concensus wrt. attribute generation and use
- Reference standards used only occasionally
- A 6 inch (15.2 cm) continuous line used for measuring intensity (psychological research)
- All kinds of sensory attributes
- Selection of attributes for all modalities or fewer
- Risk for perceptual dumping considered in attribute selection – include e.g. ”other
impressions”
- Panel leader is passive member in selecting attributes; facilitates the process
→ Many variations on this method but should not be called QDA!
Lecture 2: Selection and Training of Sensory Panels
- Chapter 3 – Principles of good practice; 3.5 Panellist consideration.
After the lecture the student is expected to:
- Know how to select assessors for sensory panels for different purposes
- Understand the role of the panel leader for the success of sensory projects
- Know different manners of attribute generation
- Be able to generate sensory attributes for the QDA in this course
- Understand and be able to explain how different methods of descriptive analysis require different
degrees of training
- Know and be able to apply the methods of consensus training and individual vocabularies
Why select sensory subjects?
→ Find all the nuances that can be detected e.g. intensity.
How to select sensory subjects?
→ Recruitment of analytical sensory panels (repeatable and precise):
- Internal or external
- Age 20-55 (senses are stable)
- Test about twice the number of subjects needed
- Announcement… media, canteen, class, etc.
→ Panel selection by questionnaire:
- Personality: Be able to work in a team; ”Cosmopolitan” preferences; Positive not over-
bearing; Good listener and communicator; Committed and flexible.
- Health: General good health condition; Documentation of any health restrictions
(medication, allergies, pregnancy, false teeth, …)
- Availability
→ Panel selection by tests for sensory ability
Example of a rapid taste
test is papers dipped in
different concentrations
to test if you taste the
basic taste.
Rapid odour test Sniffin’
sticks:
How to train sensory subjects?/ When is the panel trained enough?
→ General training: familiarisation with test protocols, discrimination tests, intensity scaling
→ Product specific training: describe what the different properties are, especially important for
descriptive analysis.
→ Attribute specific training: making concepts cognitive clear (=understandable) to the sensory panel
,Selection and training of subjects needed for descriptive, not for threshold and discrimination:
Check performance over time?
→ Monitoring of performance of analytical sensory panels
- Inter individual variation (between individuals)
- Intra individual variation (within individual)
- Sequential analysis – long-term performance
- Feedback on performance to individual or panel
What are the roles and personal characteristics of a panel leader?
→ Type of roles (depending on the method)
- Passive facilitator (e.g. QDA)
- Directive leader (e.g. Spectrum)
→Personal characteristics
- Non-judgemental/opinionated
- Sensitive and assertive, but diplomatic
- Leading panel discussions but active listener
- Recognises and guards against moderator bias
- Ability to motivate panel
Lecture 1: Descriptive Sensory Analysis
- Chapter 10 – Descriptive analysis
After the lecture the student is expected to:
- Know the principles of methods such as mapping, napping, Flash Profile and their field of application
What is descriptive sensory analysis?
- A method aiming to provide a quantitative measure of the sensory properties for a set of
products
- A number of different approaches
o Trademarks (QDA and Spectrum)
o Speed versus accuracy (accuracy not good with rapid methods; training panel for a
long time gives a food accuracy, find a lot of details)
o Relations to instrumental measures (perception of sourness and ph value in milk; if
correlated that replacement of sensory panel by instrument)
, Why using descriptive sensory analysis?
- Product reformulations
- New product development
- Quality control
o Acceptability to specified target
o Calibration of instrumental methods
- Brand mapping (e.g. identifying sensory niches)
- Consumer preference mapping
- Research
o Understanding relationships between product/process/production properties and
perceptible properties
What are the main differences between methods?
- Generation of sensory descriptors
- Degree of subject training
- Use of reference materials and scaling
What is the flavor profile method?
- Consensus method (4-6 judges; 2-3 weeks training)
- A qualitative descriptive method – no statistical analysis possible due to consensus scores
- Reference materials for discussing and defining
- Limited to flavour impressions
- Estimate intensity of flavour attributes (aroma, flavour, mouth feel and aftertaste). Expand
with - + ½ ↑ ↓
- Estimate intensity of overall amplitude (overall balance and blending of product):
What is the Quantitative Descriptive Analysis?
- Data from individual panel members (n=10-12) in sensory booths
- Concensus wrt. attribute generation and use
- Reference standards used only occasionally
- A 6 inch (15.2 cm) continuous line used for measuring intensity (psychological research)
- All kinds of sensory attributes
- Selection of attributes for all modalities or fewer
- Risk for perceptual dumping considered in attribute selection – include e.g. ”other
impressions”
- Panel leader is passive member in selecting attributes; facilitates the process
→ Many variations on this method but should not be called QDA!
