TOPIC 6 Sensory Evaluation Flashcards
what aspects of sensory evaluation in cosmetics ? (4)
○ packaging appearance
○ product appearance
○ product texture
○ fragrance
types of assessments in performance evaluation system (3)
○ instrumental assessment (physical / chemical) - presence of atttribute
○ expert assessment (sensory / clinical) - noticeability of attribute
○ acceptance studies (consumer) - importance of attribute
importance of expert assessment
experts are more sensitive and better able to describe various attributes with proper terminologies
importance of sensory evaluation in technology development (4)
○ prototype screening vs design targets
○ predictive testing for consumer acceptance
○ reduce uncertainty and risks in decision making
○ claims support
importance of sensory evaluation in quality control (3)
○ ensure no noticeable differences with product changes
○ stability over time (fresh vs aged)
○ quality investigation
four (4) steps of method development
- define objective
- get started
- assess
- validate / use
three (3) steps / questions of method validation ie. step 4 of method development
- is the method relevant ?
- is the method accurate and precise ?
- is the method robust ?
types of sensory / consumer evaluation (3)
objective test
○ difference / discrimination test
○ descriptive analysis (intensity of characteristics)
subjective test
○ affective testing
types of difference tests (3)
○ pair test (compare A & B)
○ triangle test (finding odd one out between A, B, & C)
○ duo-trio test (testing A & B against control)
how many panelists used in discrimination test
25-50
advantage (1) of discrimination test
quick and simple
disadvantage (1) of discrimination test
limited results: no elaboration on differences
discrimination test is used when …
samples are considered to be “confusable” ie. differences are not obvious but need to be investigated
common uses for discrimination test (6)
○ screening and training assessors
○ determining sensitivity thresholds
○ quality assurance / quality control
○ investigating effect of ingredient / process changes
○ investigating taint
○ preliminary assessments
two (2) requirements of descriptive analysis
○ extensive training
○ regular calibration (every year or 1/2 year)
how many panelists in descriptive analysis
8-12
why are there less panelists in descriptive analysis than discrimination test (2)
○ descriptive analysis is more time consuming and tedious
○ descriptive analysis requires qualified panelists that are challenging to recruit many of
sequential monadic method for descriptive analysis (3)
○ samples evaluated individually and independently
○ one after another
○ not compared to one another
advantages (2) of descriptive analysis
○ detailed quantitative information
○ able to determine degree of effect of certain changes
disadvantage (1) of descriptive analysis
time consuming
how many panelists in affective / hedonic evaluation (consumer study)
75-150
advantage (1) of affective / hedonic evaluation (consumer study)
provides essential information on consumer preference due to direct involvement
disadvantage (1) of affective / hedonic evaluation (consumer study)
may be difficult to get a representative sample of consumers
analysis of affective / hedonic evaluation (consumer study)
mean hedonic scores calculated for each product and ANOVA (analysis of variance) applied to data set
