1. Jenny Scott FDA/CFSAN U.S. Delegate – Codex Committee on Food Hygiene
Microbiological Criterion to Assess the Acceptability of a Food Lot -Example 2
Jenny Scott
FDA/CFSAN
U.S. Delegate – Codex Committee on Food Hygiene

2. Working Group Members Argentina Thailand Uruguay United States
Josefina Cabrera
Marité Carullo
Thailand
Virachnee Lohachoompol
Uruguay
Inés Martinez
United States
Jenny Scott (Chair)
John Bowers
Philip Bronstein
Kerry Dearfield
Emily Mathusa
Mark Powell
Al Rainosek

3. Purpose
The purpose of these microbiological criteria is to assess the acceptability of a milk powder lot intended for direct consumption. (Milk powder will be consumed without further treatment to inactivate microorganisms.)

4. Who should establish and who should apply?
Established by: Competent authorities or food business operators
Applied by: Competent authorities or food business operators

5. Food or food process (point in food chain where the MC is applied)
Milk powder at the manufacturing facility or in commerce for verification of lot acceptability by competent authorities as part of domestic food control procedures
Milk powder received for import/export inspection by competent authorities
Milk powder for lot acceptance by food business operators purchasing from a supplier
Milk powder at point of manufacture as a verification of process control

6. Organisms of concern Hygiene Criteria: Food Safety Criterion
Mesophilic Aerobic Microorganisms
Enterobacteriaceae
Food Safety Criterion
Salmonella spp.

7. Rationale for the organisms selected (food safety)
Epidemiological data suggest that the only significant hazard to be controlled during manufacturing of dried products is Salmonella.
Staphylococcus aureus or Bacillus cereus are only present sporadically at very low levels or occur as a result of major breakdowns of GHP.
ICMSF Book 8

8. Rationale for the organisms selected (food hygiene)
Mesophilic Aerobic Microorganisms - indicators of general contamination, shelf life or spoilage; not usually related to a health hazard
Enterobacteriaceae – high numbers frequently indicate inadequacy of general hygiene
ICMSF Book 2

9. Sampling plans Organism Analytical unit n c m M
Mesophilic Aerobic Microorganisms
10 g 5 2
104
CFU/g
105
Enterobacteria-ceae
< 3 MPN/g
9.4 MPN/g
Salmonella spp.
25 g 10
Not detected in 25 g

10. Performance Characteristics of the Sampling Plans
Enterobacteriaceae n c m M Pa
Log CFU/g* 5 2
<3 MPN/g
(<0.48 log CFU/g)
9.4 MPN/g
(0.97 log CFU/g)
0.05
0.68
* std. dev. assumed to be 0.25 log CFU/g
Assuming a log normal distribution, this sampling plan will provide 95% probability that a lot of food containing a geometric mean of 0.68 log CFU/g (4.79 CFU) and a std. dev. of 0.25 log CFU/g will not be accepted.

11. Performance Characteristics of the Sampling Plans
Salmonella n c m Pa
Log CFU/g* 10
Absence in 25 g
0.05
-1.97
* std. dev. assumed to be 0.25 log CFU/g
Assuming a Poisson-log normal distribution, this sampling plan will provide 95% probability that a lot of food containing a geometric mean concentration of log CFU/g (0.011 CFU/g) and a std. dev. of 0.25 log CFU/g will be detected and rejected if any of the 10 analytical units are positive for Salmonella.

12. Method(s) of analysis Mesophilic aerobic colony count: ISO 4833
Enterobacteriaceae: ISO (MPN technique)
Salmonella spp.: ISO 6785 (Milk and milk products -- Detection of Salmonella spp.) or ISO 6579 (Horizontal method for the detection of Salmonella spp.)

13. Interpretation of results
Salmonella
Satisfactory if all values observed indicate the absence of the bacterium; the lot is accepted
Unsatisfactory if the presence of the bacterium is detected in any of the sample units; the lot is rejected

14. Interpretation of results
Mesophilic aerobic colony count and/or Enterobacteriaceae
Satisfactory, if all the values observed are ≤ m; the lot is accepted
Acceptable, if a maximum of c units (2) have values that are between m and M and the rest of the values observed are ≤ m; the lot is accepted
Unsatisfactory if one or more of the values observed is > M or more than c units (2) are between m and M; the lot is rejected

15. Actions in case of non-conformance – food business operators
Salmonella criterion
Food business operators purchasing from a supplier: (1) Notify the supplier; (2) do not use the milk powder, or if the milk powder has been used do not ship the product; (3) if product has been shipped, recall the product; and (4) determine appropriate steps with respect to the supplier.
Food business operators manufacturing the milk powder: (1) prevent the affected lot from being released for human consumption; (2) recall the product if it has been released for human consumption; and (3) determine and correct the root cause of the failure.

16. Actions in case of non-conformance – competent authorities
Salmonella criterion
Prevent the affected lot from being released for human consumption;
Ensure recall of product by the food business operator if it has been released for human consumption;
Reject lot at port of entry.

17. Actions in case of non-conformance – food business operators
Mesophilic aerobic microorganisms and/or Enterobacteriaceae
Food business operators purchasing from a supplier: (1) Notify the supplier; (2) determine appropriate disposition of the non-conforming lot (e.g., refuse lot or accept marginal quality lot, depending on business contractual arrangements)
Food business operators manufacturing the milk powder: (1) Check on the efficacy of heat treatment and controls for prevention of recontamination, (2) determine and correct the root cause of the failure (3) as appropriate, review and revise monitoring procedures, environmental surveillance and prerequisite programs, and (4) determine disposition of the lot.

18. Actions in case of non-conformance – competent authorities
Mesophilic aerobic microorganisms and/or Enterobacteriaceae
Determine whether to reject lot at port of entry (e.g., destroy at port of entry or return to country of origin)
notify the manufacturing facility to take corrective actions with respect to hygiene practices and to verify the efficacy of heat treatment and procedures to prevent recontamination
reject lot as part of domestic food control procedures; determine disposition of the lot (e.g., require destruction, allow reconditioning of the lot or use of the lot for other purposes)