TOPIC 6 Sensory Evaluation

Question 1

what aspects of sensory evaluation in cosmetics ? (4)

Answer 1

○ packaging appearance
○ product appearance
○ product texture
○ fragrance

Question 2

types of assessments in performance evaluation system (3)

Answer 2

○ instrumental assessment (physical / chemical) - presence of atttribute
○ expert assessment (sensory / clinical) - noticeability of attribute
○ acceptance studies (consumer) - importance of attribute

Question 3

importance of expert assessment

Answer 3

experts are more sensitive and better able to describe various attributes with proper terminologies

Question 4

importance of sensory evaluation in technology development (4)

Answer 4

○ prototype screening vs design targets
○ predictive testing for consumer acceptance
○ reduce uncertainty and risks in decision making
○ claims support

Question 5

importance of sensory evaluation in quality control (3)

Answer 5

○ ensure no noticeable differences with product changes
○ stability over time (fresh vs aged)
○ quality investigation

Question 6

four (4) steps of method development

Answer 6

1. define objective
2. get started
3. assess
4. validate / use

Question 7

three (3) steps / questions of method validation ie. step 4 of method development

Answer 7

1. is the method relevant ?
2. is the method accurate and precise ?
3. is the method robust ?

Question 8

types of sensory / consumer evaluation (3)

Answer 8

objective test
○ difference / discrimination test
○ descriptive analysis (intensity of characteristics)

subjective test
○ affective testing

Question 9

types of difference tests (3)

Answer 9

○ pair test (compare A & B)
○ triangle test (finding odd one out between A, B, & C)
○ duo-trio test (testing A & B against control)

Question 10

how many panelists used in discrimination test

Answer 10

25-50

Question 11

advantage (1) of discrimination test

Answer 11

quick and simple

Question 12

disadvantage (1) of discrimination test

Answer 12

limited results: no elaboration on differences

Question 13

discrimination test is used when …

Answer 13

samples are considered to be “confusable” ie. differences are not obvious but need to be investigated

Question 14

common uses for discrimination test (6)

Answer 14

○ screening and training assessors
○ determining sensitivity thresholds
○ quality assurance / quality control
○ investigating effect of ingredient / process changes
○ investigating taint
○ preliminary assessments

Question 15

two (2) requirements of descriptive analysis

Answer 15

○ extensive training
○ regular calibration (every year or 1/2 year)

Question 16

how many panelists in descriptive analysis

Answer 16

8-12

Question 17

why are there less panelists in descriptive analysis than discrimination test (2)

Answer 17

○ descriptive analysis is more time consuming and tedious
○ descriptive analysis requires qualified panelists that are challenging to recruit many of

Question 18

sequential monadic method for descriptive analysis (3)

Answer 18

○ samples evaluated individually and independently
○ one after another
○ not compared to one another

Question 19

advantages (2) of descriptive analysis

Answer 19

○ detailed quantitative information
○ able to determine degree of effect of certain changes

Question 20

disadvantage (1) of descriptive analysis

Answer 20

time consuming

Question 21

how many panelists in affective / hedonic evaluation (consumer study)

Answer 21

75-150

Question 22

advantage (1) of affective / hedonic evaluation (consumer study)

Answer 22

provides essential information on consumer preference due to direct involvement

Question 23

disadvantage (1) of affective / hedonic evaluation (consumer study)

Answer 23

may be difficult to get a representative sample of consumers

Question 24

analysis of affective / hedonic evaluation (consumer study)

Answer 24

mean hedonic scores calculated for each product and ANOVA (analysis of variance) applied to data set

Question 25

affective / hedonic evaluation (consumer study): acceptance test

Answer 25

level of liking: circle how much you like the product

Question 26

affective / hedonic evaluation (consumer study): preference test

Answer 26

pair comparison: circle the product you prefer (does not necessarily mean you like the product chosen)

Question 27

types of affective / hedonic evaluation (consumer study) questionnaires: acceptance test (3)

Answer 27

○ hedonic scale (most common)
○ just about right scale
○ smiley scale

Question 27

types of affective / hedonic evaluation (consumer study) questionnaires: preference test (3)

Answer 27

○ paired preference test
○ ranking test
○ sample ballot