DETERMINATION OF COLIFORMS IN FOODS USING VIOLET RED BILE AGAR

HPB Method MFHPB-31
March 2001

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1. APPLICATION

This method is applicable to the enumeration of coliforms in foods and food ingredients to determine compliance with the requirements of Sections 4 and 7 of the Food and Drugs Act.

Where an Official Method for certain products is specified, that method shall be followed. This method is not applicable for the enumeration of coliforms in fish, fish products or other "seafood".

This revised method replaces MFHPB-31, dated April 1997.

2. DESCRIPTION

This method has been shown to produce satisfactory results with naturally-contaminated foods for the detection of coliforms (8.2 -8.5).

3. PRINCIPLE

The presence of coliforms in a food may indicate that it has been manufactured under unsanitary conditions. This procedure estimates the number of viable coliforms per g or mL of product. A portion of the product is mixed and incubated with a selective medium by the pour plate technique. A selection of typical red-purple colonies are subjected to confirmatory tests. The number of confirmed coliforms is calculated from the ratio of colonies confirmed to colonies tested.

4. DEFINITION OF TERMS

See Appendix A of Volume 2.

5. COLLECTION OF SAMPLES

See Appendix B of Volume 2.