The methodology for determine a sensory shelf life of a product
To determine an effective sensory shelf life (not the shelf life based on microbiological result) is also important to a food/beverage product. How to do it?
Some folks would like to estimate the sensory shelf life like the way did for the microbiological or chemical shelf life by employing speeding test (increase the storage temperature and speeding the growth or reaction).
We, however, would like to point out it is not proper to employ the speeding experiment design for determining your sensory shelf life of your product. Here are why：
- The reaction rate affected by temperature can be different at different temperature range. Arrhenius behavior is just proper one for sensory perceptions.
- Different reaction products will have different effects on the reaction rates.
- We found that you will lose (shorten) your shelf life if you estimate yours by using the result at the high temperature.
In this case, the risk will include failed to have scientific data to support your shelf life, consumer may get the failure product, and you may waste your shelf life that you actual have.
What can you do to have scientific data to determine your sensory shelf life then?
We will recommend the Weibull test model to determine it.
The Weibull test model is employing the product failure theory which is suitable for sensory shelf life. We will say when people fail to accept a food product should be the product reach the failure point on certain sensory attribute. This, however, should occur before the microbiologic failure occur. If the microbial end point will reach first for your product, then you do not need to worry about sensory shelf life at all. The reason that we recommend this for commercial practices is you can employ a naïve panel (not necessary a trained panel) to conduct the project.
You also can find a software to help you on conducting the Weibull test. Here is the one https://www.e-sinew.com/MakeSense/MS-SEQC.php