What is ISO 21187 about?
ISO 21187 specifies guidelines for the establishment of a conversion relationship between the results of an alternative method and an anchor method, and its verification for the quantitative determination of the microbiological quality of milk.
ISO 21187 provides a method of analysis allowing quantification of the microbiological status of milk.
Note: The conversion relationship can be used
- To convert results from an alternative method to the anchor basis or
- To convert results/limits, expressed on an anchor basis, to results in units of an alternative method
Who is ISO 21187 for?
ISO 21187 on quantitative determination of the microbiological quality of milk is useful for:
- Manufacturers of dairy products
- Food laboratories
- Microbiologists
- Any entity related to the analysis of microbiological quality of milk
Why should you use ISO 21187?
Conversion in quantitative microbiology means expressing the result of a quantitative determination of the microbiological status of a test sample obtained with an alternative method in units of another method, an anchor method. Through this, quantitative results obtained with alternative methods can be compared to values or limits that are stated in anchor method units.
ISO 21187 specifies guidelines for establishing a conversion relationship between the results of two methods, and its verification for the quantitative determination of the microbiological quality of milk.
ISO 21187 guidelines enable you to express the results of different test methods in a common measurement scale/unit.
What is changed since the last update?
BS EN ISO 21187:2021 supersedes ISO 21187|IDF 196:2004. BS EN ISO 21187:2021 includes some technical changes with respect to ISO 21187|IDF 196:2004. These include:
- The formula describing the conversion relationship has been based on grouped data rather than data from individual samples
- Examples of how to perform outlier tests, and calculation and verification of conversion relationships have been given in a spreadsheet
