GB 4789.45-2023 National food safety standard - General rules for validation of microorganism examination methods
1 Scope
This standard specifies the general requirements for validation of microorganism examination methods in the national food safety standard.
This standard is applicable to the validation during the formulation and revision of microorganism examination methods in the national food safety standard.
2 Terms and definitions
2.1
method validation
test activity which provides objective and valid evidence to prove that the performance parameters of the analytical method meet the intended use of the method
2.2
qualitative method
method for testing the presence of a target microorganism in a sample
2.3
quantitative method
method for determining the number or concentration of target microorganisms in a sample
2.4
reference method
conventional method for culturing microorganisms, which is recognized or widely accepted
2.5
sensitivity
ability of the qualitative method to be validated to detect target microorganisms from a sample
2.6
inclusiveness
ability of the method to be validated to detect target microorganisms
2.7
exclusivity
anti-interference ability of the method to be validated against non-target microorganisms
2.8
accuracy
degree of consistency between the test results obtained by the quantitative method and the true values for a sample
2.9
specimens
part derived from a sample, used for test, and capable of reflecting the characteristics of the sample
2.10
factional detection level
contamination level of samples when a set of parallel samples is tested with the qualitative method (probability of detection: 25% to 75%)
2.11
50% limit of detection (LOD50)
concentration of target microorganisms in the sample when the probability of detection for the qualitative method is 50%
2.12
relative limit of detection (RLOD)
ratio of LOD50 for the method to be validated to that for the reference method in case a reference method is available at the time of validation
2.13
paired/unpaired analysis
in case two qualitative methods are used to simultaneously test a sample: if the enrichment method used in the first step is the same, the same specimen obtained from the sample may be used for analysis, which is called "paired analysis"; if the methods used in the first step are different, different specimens obtained from the sample are used for separate analysis, which is called "unpaired analysis".
Foreword i
1 Scope
2 Terms and definitions
3 General requirements for validation of microorganism examination methods
3.1 Selection of performance parameters
3.2 Selection of representative foods
3.3 Requirements for samples for validation
3.4 Requirements for data processing
4 Validation of performance parameters concerning microorganism examination methods
4.1 Sensitivity
4.2 Inclusiveness and exclusivity
4.3 Accuracy
Annex A Classification table of food samples for validation of microorganism examination methods
Annex B Method for calculating sensitivity
Annex C Method for calculating the accuracy of in-house validation
Annex D Method for calculating the accuracy of interlaboratory validation
