Discrimination or Difference tests are used to determine whether a significant difference exists between two or more products. Discrimination testing uses screened panelists who have been identified as key tasters through sensory acuity testing. They have been screened to determine if they can detect differences in taste, aroma, texture and appearance of products.
There are several types of discrimination tests: triangle (single/double), tetrad, duo-trio, paired difference and difference from control (DFC).
Difference testing can be used to answer the following questions:
- Does a sensory difference exist between products?
- Are specific attributes different or similar?
- Is the product the same from one production to another or from multiple facilities?
- Is the product different over time?
- When an ingredient is changed or substituted, does it change the product?
- Are products similar enough to be used interchangeably?
Difference testing can also be used to evaluate, select and/or monitor panelists. This is typically the first step in identifying future panelists for our Descriptive Panel.
Types of Discrimination/Difference Tests
Three samples presented blind; two samples are the same and one is different. The panelist is asked to choose the different/odd sample.
Three samples presented; one identified as the reference and two unknown samples. The panelist is asked to identify the sample that matches the reference.
Four samples presented; two samples are the same and the other two samples are the same. The panelist is asked to group the four samples into pairs of two for similarity.
Paired Difference Test
Two samples presented; panelist is asked to choose the sample with higher level of some specified characteristic.
Difference from Control
Several samples presented; control or reference plus one or more test samples. The panelist is asked how different the test is from the control/reference.