This document specifies the enumeration of Clostridium (C.) perfringens by colony-count technique.
This document is applicable to:
— products intended for human consumption;
— products for feeding animals;
— environmental samples in the area of food and feed production and handling;
— samples from the primary production stage.
NOTE This method has been validated in an interlaboratory study for the following food categories:
— ready-to-eat, ready-to-reheat meat products;
— eggs and egg products (derivates);
— processed fruits and vegetables;
— infant formula and infant cereals;
— multi-component foods or meal components.
It has also been validated for the following other categories:
— pet food and animal feed;
— environmental samples (food or feed production).
As this method has been validated for at least five food categories, this method is applicable for a broad range of food. For detailed information on the validation, see Clause 11 and Annex C. Since the method is not commonly used for samples in the primary production stage, this category was not included in the interlaboratory study. Therefore, no performance characteristics were obtained for this category.
This horizontal method was originally developed for the examination of all samples belonging to the food chain. Based on the information available at the time of publication of this document, this method is considered to be fully suited to the examination of all samples belonging to the food chain. However, because of the large variety of products in the food chain, it is possible that this horizontal method is not appropriate in every detail for all products. Nevertheless, it is expected that the required modifications are minimized so that they do not result in a significant deviation from this horizontal method.
This technique is suitable for, but not limited to, the enumeration of microorganisms in test samples with a minimum of 10 colonies counted on a plate. This corresponds to a level of contamination that is expected to be higher than 10 cfu/ml for liquid samples or higher than 100 cfu/g for solid samples.