Presented at 2013 Arkansas Association for Food Protection annual conference. James S Dickson, PhD Iowa State University Department of Animal Science Inter-Departmental Program in Microbiology

1. Validation of Food Processes:
In-Plant Approaches
James S Dickson, PhD
Department of Animal Science
Inter-Departmental Program in
Microbiology

2. Do the security measures at the airport work?

3.  Validation involves obtaining
evidence that control
measures, if properly
implemented, are capable
of controlling the identified
hazards. (Codex)

4. MONITORING
VERIFICATION
VALIDATION

5.  Section 417.4 of the meat and poultry
regulations requires “Every establishment
shall validate the HACCP plan’s adequacy
in controlling the food safety hazards
identified during the hazard analysis.…”
 9 CFR part 417.4 (1996)

6.  Sec 103. Hazard Analysis and Risk-Based
Preventive Controls
 Hazard Analysis
 Preventive Controls
 Corrective Actions
 Verification
 Recordkeeping
 Written Plan and Documentation

7.  Доверяй, но
проверяй
 Trust, but
verify

8. DOES HACCP WORK?
DOES YOUR HACCP WORK?

9.  adequate validation:
 supporting scientific information
 in-plant operational data
 Demonstrate:
 HACCP plan is theoretically sound
 can be implemented and that it works

10.  Considered the level of contamination
 Used that information to demonstrate
that the intervention can address the
expected level of contamination

11.  Salmonella
o Incidence?
o Population?
o Resistance to intervention?

12.  An establishment must develop data to
demonstrate, with its own employees and
equipment, and that its HACCP
system, as implemented, is capable of
achieving the expected results.

14.  What are you validating?
 Level of incoming contamination
 Effect of treatment
 Effect of overall process
 Variability of treatment/process
Iowa State Univ.

15.  Validating a Process?
 Validating an individual CCP?
 Pathogen incidence vs pathogen
reduction
Iowa State Univ.

16. Net reduction in Population ~ 1.5
log10 cfu/100g sample

17.  Dilution?
 One ingredient contaminated, other not?
 Inactivation?
 One process is lethal to the bacteria
 Uneven distribution in product?
 Probability of detection?

18.  Contamination
 Microbial growth
 Microbial death
 Joining
 Mixing
 Fractionation
 Combining two or more mechanisms
 (Impact of Microbial Distributions on Food Safety; ILSI
2010)
 Similar to “Modular Process Risk Model” (Nauta, 2002;
Int. J. Food Micobiol. 73:297)

20.  Quantitative
 Indicators?
 Aerobic bacteria
 Enterobacteriaceae
 Coliforms
 Surrogates?
 Qualitative
 Pathogens?
 Salmonella
 Listeria
 STEC’s
Iowa State Univ.

21.  Performance of the method
 Quantitative
 Minimum detection limit
 Qualitative
 Positive/negative in ?? grams
Iowa State Univ.

22. Impact of a 5 log10 reduction
on bacterial population
Intervention
Log10Population/gram
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
?
Detection
Limit

23.  How are the results influenced by
process variation?
 How are the results influenced by
random chance?

24.  1.0 - 1.8 log reduction – 8.0% (+)
 1.3 – 1.8 log reduction – 0.6%(+)
 1.5 - 1.8 log reduction – 0.0%(+)

25. Servings/hour
Servings/hour
(2 processing
lines)
HOURS Hours to 1
million units
36,000 72,000 1
144,000 288,000 4
288,000 586,000 8
432,000 864,000 12 ~14
576,000 1,152,000 16

26.  Influenced by variance
 More variance = More replications
 Calculate sample size and power

27.  Are your interventions working?
 Is your investment in food safety
paying off?
 Does your HACCP system work?

28. QUESTIONS?