MPI clarifies Listeria testing requirements under ANZ Food Standards Code Standard 1.6.1
November 06, 2015 at 11:21 AM
Following a recent enquiry to MPI on it's expectations of food businesses with respect to testing ready to eat foods fof Listeria, we have received the following information:
"The following is the agreed position of MPI -
1 FSANZ defines RTE food requiring Listeria testing as follows ref std 1.6.1;
ready-to-eat food means a food that –
(a) is ordinarily consumed in the same state as that in which it is sold; and
(b) will not be subject to a listericidal process before consumption; and
(c) is not one of the following –
(i) shelf stable foods;
(ii) whole raw fruits;
(iii) whole raw vegetables;
(iv) nuts in the shell;
(v) live bivalve molluscs
2 The food standards code states:
For RTE food in which growth on Lm can occur n=5, c=0 m=not detected in 25g
Std 1.6.1 FSC 26-2-15
To confirm the food is safe to be consumed this standard must be met.
MPI published a guidance document in January 2012 which states:
3.5.3 Compositing of product samples
To demonstrate compliance with microbiological criteria such as that contained within the Food Standards Code, the number of samples needed is ‘n’ and will be no less than 5 in all cases limits.
When testing for the verification of Listeria control measures, e.g. operator defined limits or product testing, it is good practice to analyse more than a single product sample. The number of samples needed is ‘n’ and will be no less than 5 25 g samples in all cases. Testing costs may be able to be reduced by compositing samples i.e. testing a set of samples as a single sample provided the test does not become less sensitive by doing this. The laboratory needs to know when samples are to be composited. The samples should all be from the same batch or production line. This then gives a single analytical test sample of the total 125g. The laboratory will then report the result per 125g. When very large numbers of foods need to be tested e.g. when a contamination event has occurred it may be possible to composite more than 5 samples. However this may not always be practical and should be discussed in advance with the laboratory.
Compositing of product samples by the food operator should only occur if samples are taken prior to final packaging by automatic samplers. Otherwise compositing should be done by the laboratory.
From: Guidance for the Control of Listeria monocytogenes in Ready-To-Eat Foods
Part 3: Microbiological testing for verification of the control of Listeria monocytogenes
In this document the minimum frequency of sampling is recommended as once every 10 batches. i.e. 5 samples from the batch every 10 batches of product manufactured.
The Food Standards Code does not give a frequency of sampling and it is expected to be up to the operator to justify.
For presence-absence testing (as in standard 1.6.1 above), there should not be any loss in sensitivity if the samples are composited. Therefore companies doing this can be deemed to be meeting the requirements of std 1.6.1."