What is ISO 21528-2 about?
ISO 21528-2 is the second part of the multi-series European standard. ISO 21528-2 is intended to provide general guidance for the examination of products not dealt with by existing International Standards and to be taken into account by organizations preparing microbiological test methods for application to foods or animal feeding stuff.
ISO 21528-2 specifies a method for the enumeration of Enterobacteriaceae. It applies to:
- Products intended for human consumption and the feeding of animals
- Environmental samples in the area of primary production, food production, and food handling.
This technique is intended to be used when the number of colonies sought is expected to be more than 100 per milliliter or gram of the test sample.
Who is ISO 21528-2 for?
ISO 21528-2 on microbiology of the food chain is useful for:
- Food technologists
- Microbiologists
- Chemical Engineers
- Food and safety department
Why should you use ISO 21528-2?
Enterobacteriaceae are a large family of Gram-negative bacteria including Klebsiella, Enterobacter, Citrobacter, Salmonella, Escherichia coli, Shigella, Proteus, Serratia, and others.
ISO 21528-2 standard specifies horizontal methods for counting and selecting colonies for Enterobacteriaceae and provides complete instructions and procedures from sample preparation to testing results.
ISO 21528-2 benefits users by providing detailed, standardized procedures for quality control. The laboratory should implement a quality control system to ensure that the equipment, reagents, and techniques are appropriate for the test.
Using BS EN 17203, the user receives detailed information regarding how Enterobacteriaceae can be detected by colony counting. This helps to standardize the quality of food items, thereby improving their shelf life.
What’s changed since the last update?
BS EN ISO 21528-2:2020 supersedes BS EN ISO 21528-2:2004. BS EN ISO 21528-2:2020 includes some technical changes concerning BS EN ISO 21528-2:2004. These include:
- Confirmation step has been changed by replacing glucose agar with glucose of medium
- Precision data based on the results of an interlaboratory study using the method according to this revised edition has been included in an informative annex
- In 6.4, a water bath capable of being maintained between 44 °C to 47 °C has been added to the list of equipment
- In 9.3.2, the temperature has been reduced from “47 °C to 50 °C” to “44 °C to 47 °C”