Sensory Test Method 
Sensory Test Method
discrimination/Difference Test
Ranking
Scaling
Consumer preference tests
Difference tests
Ranking
Scaling
Discrimination/Difference tests
Difference tests are the simplest and most sensitive form of product testing
They are used to determine: whether or not a difference in some specific attribute exists between two samples if one sample is preffered to another
Hoewer, cannost be used to determine how large is the difference or preference between samples
Application of Difference tests
Routine quality control
Monitoring the effects of change in production (e.g. effect of ingredient substitution, process modifications, changes in raw material suppliers)
These tests are often used as the first step in a more complex sensory evaluation process, with a difference between samples indicating the need for further testing
Commonly Used Difference Tests
Paired comparison two samples compared, one to be selected (1-tailed) where preference is asked either sample can be correct (2-tailed)
Triangle test only one response can be correct
Difference to refference/control duo-trio multiple comparison
Example of a Paired Comparison Test
A paired comparison test was run to evaluate the effect of storage on the flavour of soup powder. A control sample (A) was compared with a sample which had been subjected to long-term storage (B). After reconstitution, the samples were coded with three digit random numbers and presented to a panel of twelve. Six of the panelists were instructed to taste B first. The panelists were asked “Can you detect a difference in flavour between two samples?” Nine of twelve panelists answered “YES” to this question. Did storage have a significant effect on the flavour of the soup powder?
Using a one-tailed binominal table, the minimum number of correct responses needed to establish a significant difference at the 5% probablility level (i.e.
discrimination/Difference Test
Ranking
Scaling
Consumer preference tests
Difference tests
Ranking
Scaling
Discrimination/Difference tests
Difference tests are the simplest and most sensitive form of product testing
They are used to determine: whether or not a difference in some specific attribute exists between two samples if one sample is preffered to another
Hoewer, cannost be used to determine how large is the difference or preference between samples
Application of Difference tests
Routine quality control
Monitoring the effects of change in production (e.g. effect of ingredient substitution, process modifications, changes in raw material suppliers)
These tests are often used as the first step in a more complex sensory evaluation process, with a difference between samples indicating the need for further testing
Commonly Used Difference Tests
Paired comparison two samples compared, one to be selected (1-tailed) where preference is asked either sample can be correct (2-tailed)
Triangle test only one response can be correct
Difference to refference/control duo-trio multiple comparison
Example of a Paired Comparison Test
A paired comparison test was run to evaluate the effect of storage on the flavour of soup powder. A control sample (A) was compared with a sample which had been subjected to long-term storage (B). After reconstitution, the samples were coded with three digit random numbers and presented to a panel of twelve. Six of the panelists were instructed to taste B first. The panelists were asked “Can you detect a difference in flavour between two samples?” Nine of twelve panelists answered “YES” to this question. Did storage have a significant effect on the flavour of the soup powder?
Using a one-tailed binominal table, the minimum number of correct responses needed to establish a significant difference at the 5% probablility level (i.e.