ISO 7402:1993 PDF Download

ISO 7402:1993 is a standard that provides general guidelines for the enumeration of Enterobacteriaceae in products intended for human consumption or animal feeding stuffs. This is achieved through two main techniques: the most probable number (MPN) technique and the colony-count technique.

The MPN technique involves incubating the sample at either 35°C or 37°C in a liquid medium and then calculating the most probable number of Enterobacteriaceae present. This method is recommended for samples with low bacterial counts.

On the other hand, the colony-count technique involves incubating the sample at either 35°C or 37°C on a solid medium and then counting the number of colonies formed. This method is preferred for samples with higher bacterial counts.

The standard does not specify the exact procedures or specific media to be used but rather provides general guidance on the enumeration methods. It aims to ensure consistency and accuracy in the enumeration of Enterobacteriaceae, which are important indicators of hygiene and food safety.