European Commission stakeholder consultation setting microbiological criteria for foodstuffs in community legislation

Comments by Dr Barbara M. Lund, Visiting Scientist, Institute of Food Research in response to a letter from the Food Standards Agency dated 21.1.2003

6 February 2003

1. Draft Commission Regulation on microbiological criteria for foodstuffs and food production.
Draft 9.12.2002. SANCO/4198/2001, rev 4.

Page 2, paragraph (8) This includes the statement: "The opinion recommended that it must be an objective to keep the concentration of Listeria monocytogenes in food below 100 cfu/g."

Comment: It should be made clear that the objective is to keep the concentration of Listeria monocytogenes below 100/g up to the point of consumption.

It is important to stress at each stage that this is a criterion at the point of consumption. In a news journal the above opinion has been cited as though it was a sufficient standard at the point of production. In many foods in which L.monocytogenes can multiply during storage and distribution it would be dangerous to interpret this criterion as being applicable at the point of production.

Page 4 Definitions 2. (c) states "Batch means a group or set of products obtained from a given process under practically identical conditions"

Comment: It is advisable that the definition of Batch should be modified as follows:

"Batch means a group or set of products obtained from a given process under practically identical conditions all packages of which bear a batch number that identifies production during a particular time interval and usually from a particular critical processing unit."

Page 5 Definitions 2 (d)

Comment: This paragraph should be modified as follows, in order to make clear in this document the meaning of "use-by" date and "minimum durability period".

"Shelf-life means either the period corresponding to the "use-by" date (the date after which the foodstuff is likely to constitute a danger to human health) of products, or the minimum durability period (the date until which the foodstuff retains its specific properties when properly stored; the "best before" date) as defined respectively in Articles 9 and 10 of Directive 2000/13/EC............."

Page 6 paragraph 3

Comment: The last sentence states - "Sampling of production areas and equipment may be used as part of the procedures"

I suggest that this be modified to read - "Sampling of production areas and equipment should be used as part of the procedures to ensure hygiene control."

See Tompkin, R.B. (2002) Control of Listeria monocytogenes in the food-processing environment. Journal of Food Protection 65 709-725.

Annexe 1, Microbiological criteria for foodstuffs

Page 8, Criteria for Listeria monocytogenes, Food category 2

Comment: This criterion allows ready-to-eat foods that support the growth of L. monocytogenes and have a long shelf-life (no shelf-life is specified) to be placed on the market when they contain (e.g.) 90 L. monocytogenes /g. Foods in this category include some that have been linked causally to outbreaks of listeriosis e.g. soft cheeses (particularly mould-ripened), liver pate, jellied pork tongue, sliced turkey meat, and other products that allow the growth of L. monocytogenes, including vacuum-packaged meats, cooked fish products. There is a need to specify a much more stringent microbiological criterion for these products at the end of production, which is the point where such testing can be applied most effectively.

These include foods that either do not undergo a listericidal process, or that are subject to conditions that allow recontamination after any listericidal treatment.

Superscript 3 indicates that the exact value of m is not specified. Many businesses produce foods of this type that will allow multiplication of L. monocytogenes and have long shelf lives. A high proportion of these businesses are in no position to determine for their products the limit value, m, that will ensure that their product has fewer than 100 L. monocytogenes/g at the end of shelf-life. There is an urgent need for relevant information to be given regarding the criteria for L. monocytogenes at the end of production that should ensure that the number of L. monocytogenes present at the end of shelf-life is lower than 100/g.

The criterion at the point of production for ready-to-eat foods that have been associated causally with listeriosis, or are able to support the growth of L. monocytogenes needs to be made clear and sufficiently stringent. The position adopted by the Canadian Food Directorate, which is given below, is an example of a good approach to the control of this bacterium.

Compliance criteria for Listeria monocytogenes in ready-to-eat foods at the end of production (modified from Farber and Harwig (1996) The Canadian position on Listeria monocytogenes in ready-to-eat foods. Food Control 7, (4/5) 253-259.)

 

Category of RTE food	Criteria for L. monocytogenes	Action
1. Products that have been linked causally to listeriosis, e.g. soft cheese, liver pate, jellied pork tongue	Absence in 50g	Class I recall to retail level. Consideration of public alert. Appropriate follow up at plant level
2. All other RTE foods that support growth of L. monocytogenes and have a refrigerated shelf life longer than 10 days	Absence in 25g	Class II recall to retail level. Consideration of public alert. Appropriate follow-up at plant level
3. RTE foods supporting growth of L. monocytogenes but with a shelf life less than or equal to 10 days, and all RTE foods not supporting growth, including foods with: pH 5.0 and 5.5 and water activity less than 0.95; or pH less than 5.0 regardless of water activity; or foods with water activity less than or equal to 0.92: or frozen foods.	100 cfu/g and adequate GMP n = 5; c = 0 .............................. 100 cfu/g and inadequate or no GMP n = 5; c = 0 ................................ more than 100 cfu/g n = 5; c = 0	Allow sale, but follow-up at plant level .............................. Consider Class II recall or stop sale and follow-up at plant level .......................................... Class II recall or stop sale and follow-up at plant level

The sampling scheme for these foods is indicated briefly in the Table given below (abbreviated from that in Farber and Harwig, 1996)

The sampling scheme for ready-to-eat (RTE) foods being analysed for L. monocytogenes (LM) (modified from Farber and Harwig, 1996)

Food Product	Sampling	Analysis	Type of analysis
1. RTE foods causally linked to listeriosis	5 sample units (100g or ml each) taken at random from each lot	5 x 10g or 2 x 25g analytical units are either analysed separately or composited	Enrichment only
2. All other RTE foods supporting growth of LM with refrigerated shelf-life >10 days	5 sample units (100 g or ml each) taken at random from each lot	5x 5g analytical units are either analysed separately or composited	Enrichment only
3. RTE food supporting growth of LM with a refrigerated shelf-life = 10 days, and all foods not supporting growth	5 sample units (100g or ml each) taken at random from the lot	5x 10g analytical units are analysed separately Where enrichment is necessary 5x 5g analytical units are analysed separately or composited	Direct plating   Enrichment

Page 8. Subscript 1

Comment: This should be modified to read "n = number of sample units required for testing;
c = the maximum allowable number of sample units yielding results between m and M, or greater than m.

Page 12

Comment: We note that, according to the letter from Robert Coleman dated 17.12.2002 scientific opinions regarding Salmonella, verotoxigenic E.coli and Staphylococcus aureus are awaited.

Discussion paper On strategy for setting microbiological criteria for foodstuffs in Community legislation (SANCO) 1252/2001

Page 6, Paragraph 3, Opinion of the Scientific Committee

It is stated in this paragraph that microbiological criteria should take into account regional differences in the prevalence of pathogens and changes in food animal production practice.

Comment: The implications of this statement are not clear. The purpose of microbiological criteria is stipulate criteria that safeguard the consumer and to prevent foodborne disease. In view of the widespread in trade of foods throughout the EU, Performance Criteria and the Process Criteria in order to provide safe foods need to take account of the most extensive prevalence of pathogens that is likely to occur.

Page 11

The last paragraph contains the following sentences (1) "Nevertheless, it has to be borne in mind that a single satisfactory sample does not guarantee the hygienic status of the batch", …(2) ."when competent authorities are taking samples from foodstuffs at retail level for monitoring purposes, it is also possible to use single samples as part of an overall approach to official control"

Comment: Sentence 1 is a considerable understatement. It should be pointed out that because the quantity of a food sampled is an extremely small part of the batch, the risk of accepting a contaminated batch of food is very high. For example, if 10% of samples of a batch of food are contaminated, with a sampling plan that includes n = 5 and c = 0 there is a 59% probability that the batch will be accepted. (ICMSF Microrganisms in Foods,2. Sampling for microbiological analysis: Principles and specific applications, 2nd ed. 1986 p 89).
Sentence 2. The figures given above show that a high proportion of contaminated batches will go undetected if single samples are used in monitoring.

Page 12 paragraph 3

Includes the sentence "However, it is good to keep in mind that sampling is often a greater source of differences in test results".

Comment: It is not the process of sampling that is the source of differences, but the level of contamination of the batch.

Page 13 paragraph 2

This stresses the importance of the HACCP approach and process controls. It is important, however, to state that where the production does not involve a stage (such as pasteurization of milk or heat treatment of low-acid foods) that will inactivate bacteria or where there is a risk of post-process contamination, end product testing and environmental testing are needed.

Pages 14-15

Criteria for ready-to-eat foods and certain other categories of food.

Comment: The list of microorganisms should include verocytotoxigenic E.coli

 

Additional comment here