AS 4659.2:2015 pdf – Guide to determining the equivalence of food microbiology test methods Part 2: Quantitative tests

AS 4659.2:2015 pdf – Guide to determining the equivalence of food microbiology test methods Part 2: Quantitative tests.
The Australian Standard method against which the alternate method will be compared.3.7Target organism
The genus，species，antigenically，toxicologically or physiologically defined group oforganisms which the reference method is designed to detect.
4PROCEDURE
4.1 Define the equivalence determination
The equivalence determination should be defined in terms of the following:(a) The target organism’s genus,species, serotype, etc.
(b)The matrix under examination; the food and the characteristics that define it—the
matrix should be defined in terms of characteristics such as pH, solids level, season ofproduction，brand name，water activity，presence and composition of preservatives
etc. depending upon the nature of the matrix.
NOTE: When determining equivalence of an alternate method the laboratory should select thematrices to be included in the evaluation from those within the scope of the standard method.
This Standard is not intended for the validation of matrices outside of the scope of either the
alternate method or the standard method.Reference should be made to standard texts and theliterature to support the choices of matrices. The choice should take into account the range ofsamples tested by the laboratory and the effects that the natural variation in significantparameters may have on the detection of the target organism.
(c)The alternate method—precisely defined by reference to a publication, manufacturer’s
instructions and any optional procedures employed or deviation from the publishedmethod.
(d) The reference method——including the specification of any optional steps.
For example, the validation of the use of XYZ agar as an alternative to Baird Parkeragar in the AS 5013.12.1 method for the enumeration of coagulase positivestaphylococci, from custards containing spices and flavours and a pH greater than 4.5.(e)Steps of methods which are to be compared，for example, the alternate method may
completely replace the reference method or only a section of the reference method.(fThe range of colony forming units for which the alternate method is deemed
equivalent.
4.2 Define the conditions of the equivalence determination
The conditions of the equivalence determination should be defined in terms of thefollowing:
(a) The laboratory where testing is performed.
(b)Controls observed by the laboratory during testing，for example controls on the
environment of the laboratory，prevention of cross contamination, controls on mediaand reagents, calibration of equipment, etc. where these factors are considered criticalto the success of either method.
(c) The staff performing the tests (experience, qualifications,etc.).