Standards Development

Scope

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. 

Purpose

In the framework of Microbial Risk Assessment (MRA), several complementary approaches are developed to estimate risks posed by pathogens or spoilage microorganisms in the food chain. MRA is adopted by regulators under the auspices of the international agency for setting food standards. Predicted Microbiology is one of the recognized scientific approaches used to validate control measures within the HACCP system, as well as to assess microbiological safety and quality of food, food production processes, food storage conditions, and food preparation recommendations dedicated to consumers. This document provides technical rules, procedures and calculations to estimate the cardinal values of a microorganism and use them in combination with challenge tests results to simulate and predict its growth in the raw materials, intermediate or end-products under reasonably foreseeable food processes, storage and use conditions.

In fact, there are no harmonized protocols available to date to assess the cardinal values and there are no specific recommendations on their use to predict microbial growth.

The ISO 23691 standard provides the necessary information to conduct such assessments based on the expertise in several fields such as food microbiology, predictive microbiology and statistics.