Midterm 1.8 Sensory Evaluation Part 2 Flashcards
Types of sensory tests
Discrimination
Descriptive analysis
Threshold tests
Affective tests
Discrimination testing categories
Similarity testing - test null hypothesis that samples are not perceptibly different
Difference testing - reject null hypothesis that samples are similar
- Can be Recognition Threshold Test - perception of stimulus/difference, not needed to identify cause
- can be used to screen consumers in advance of preference test
Discrimination testing types
Triangle test - which sample is different out of 3
Constant reference Duo-Trio test - which sample matches reference?
Balanced reference Duo-Trio test - which sample matches reference (2x, different references)
ABX - Match sample to reference
Dual (Tetrad) - which sample matches with which reference
*ABX and Dual (Tetrad) not often used due to interaction effect
Descriptive analysis definition
detection and description of both qualitative and quantitative sensory aspects of a product by trained panelists of 5-100 judges to be consistent and reproducible
1) Qualitative - complete sensory descriptions using descriptors
2) Quantitative - characteristic notes are rated to determine degree of presence/intensity
Descriptive analysis uses
Thumbprint/fingerprint - specification of sensory attributes of a target product
Benchmarking - monitor competitors offerings
Quality assurance, target achieved, sensory changes over time, defining sensory-instrumental relationships
Components of descriptive analysis
Characteristic - qualitative
Intensity - quantitative
Order of appearance - time aspect
Overall impression - integrated aspect
Qualitative descriptive analysis parameters
Selected terms to describe sensory attributes should be unambiguous and discriminatory
Appearance, aroma, flavor, oral texture, and skin-feel characteristics (semi-solid and solid)
Quantitative descriptive analysis parameters
Degree to which characteristics is present using measurement scales
Category scales, line scale, magnitude estimation scale (with or without comparative modulus)
Time aspect of descriptive analysis
Perception intensity changes with time
Ex. chewing gum
Overall impression of descriptive analysis
Compilation of quantitative, qualitative, and time:
1) Total intensity of aroma/flavor
2) Balance/blend - requires sophisticated understanding
3) Overall difference
4) Hedonic rating of acceptance (like/dislike)
Affective testing definition
consumer tests where consumer is asked to rate most liked product in terms of preference, liking or acceptance
Qualitative or quantitative
Expensive test type
Qualitative affective test types
Focus groups - 8-12 consumers, moderated 1-2 hour discussion
Focus panels - 2-3 sessions with same group
One to one interviews - individually interviewed for additional insight
Quantitative affective test types
Preference test - consumers product is intended for rate preference between products
Acceptance test - affective status or how well it is liked by consumers using hedonic scales
Benefits of preference affective test
Drawbacks
Simplicity, mimic consumer conditions, more sensitive than scaled acceptance tests
Don’t use at end of sensory test, can’t represent consumer panel, cannot analyze individual attributes, no rank of degree of preference
Types of Preference Tests (Affective, Quantitative)
Simple paired preference test
Multiple paired preference test
Ranking preference test
Best-worst Preference test
Consumer rejection threshold
