BS ISO 4831:2006

Microbiology of food and animal feeding stuffs. Horizontal method for the detection and enumeration of coliforms. Most probable number technique. | Status: Current, Confirmed

1 Scope This International Standard gives general guidelines for the detection and the enumeration of coliforms. It is applicable to

• - products intended for human consumption and for the feeding of animals, and
• - environmental samples in the area of food production and food handling.

Enumeration is carried out by calculation of the most probable number (MPN) after incubation in a liquid medium at 30 °C or 37 °C.

NOTE The temperature is subject to agreement between the parties concerned. In the case of milk and milk products, the temperature of incubation is 30 °C.

This enumeration method is applicable when the number sought is expected to be in the range 1 to 100 per millilitre or per gram of test sample. A limitation on the applicability of this International Standard is imposed by the susceptibility of the method to a large degree of variability. The information given in Clause 11 provides guidance on the applicability of the method and on the interpretation of the results.