ISO/TC 34/SC 9/WG 19 - Guidelines for conducting challenge tests

This document specifies the protocols for conducting microbiological challenge tests for inactivation studies on vegetative bacteria and bacterial spores in the raw materials and ingredients, intermediate or end products. The use of this document can be extended to yeasts which do not form mycelium.

This document specifies protocols for conducting microbiological challenge tests for growth studies on vegetative and spore-forming bacteria in raw materials and intermediate or end products. The use of this document can be extended to yeasts that do not form mycelium.

This document establishes basic principles and specifies requirements and methods to determine cardinal values of bacteria and yeast strains. These methods are based on (1) the determination of maximum specific growth rates of the studied strain grown in a defined range of values of the intrinsic or extrinsic factor under study and (2) on the use of secondary models to obtain the cardinal values. These methods can be applied to all type of bacteria and yeasts. Finally, this document provides guidelines on the use of the determined cardinal values in growth simulation based on predictive microbiological models.