Validation of Food Processes: In-Plant Approaches

 James S Dickson, PhD

Department of Animal Science

Inter-Departmental Program in Microbiology

Do the security measures at the airport work?

What is Validation?

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

Validation in HACCP

MONITORING

VERIFICATION

VALIDATION

Validation of the Adequacy of HACCP plans

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)

Food Safety Modernization Act

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

What FDA and USDA are saying

, Доверяй нопроверяй

Trust, but verify

DOES HACCP WORK?

DOES YOUR HACCP WORK?

Validation of the Adequacy of HACCP plans

adequate validation: supporting scientific information in-plant operational data

Demonstrate: HACCP plan is theoretically sound can be implemented and that it works

FSIS Verification of Validated Interventions

Considered the level of contamination

Used that information to demonstrate that the intervention can address the expected level of contamination

Expected level of contamination?

Salmonellao Incidence?o Population?o Resistance to intervention?

HACCP Systems ValidationEvidence

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.

IN-PLANT VALIDATION

What is the question?

What are you validating? Level of incoming contamination Effect of treatment Effect of overall process Variability of treatment/process

Iowa State Univ.

What is the question?

Validating a Process? Validating an individual CCP?

Pathogen incidence vs pathogen reduction

Iowa State Univ.

Basic Approach

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

Reduction Attributable to ???

Dilution? One ingredient contaminated, other not?

Inactivation? One process is lethal to the bacteria

Uneven distribution in product? Probability of detection?

Microbial Distributions in Foods

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)

Alternate Approach

What are you validating?

Quantitative Indicators?

Aerobic bacteria Enterobacteriaceae Coliforms

Surrogates?

Qualitative Pathogens?

Salmonella Listeria STEC’s

Iowa State Univ.

Methods

Performance of the method Quantitative

Minimum detection limit Qualitative

Positive/negative in ?? grams

Iowa State Univ.

Impact of a 5 log10 reduction

on bacterial population

Intervention

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g10

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Detection Limit

Variation

How are the results influenced by process variation?

How are the results influenced by random chance?

5.0% 87.0% 8.0%

-12.22 0.00

-20-15-10-50510

Values in Thousands

0.0

0.2

0.4

0.6

0.8

1.0

Cell F10

Curve #1

Minimum-17457.9853Maximum 5130.1310Mean -5300.0002Std Dev 3946.3982Values 10000

Impact of Process Variation on positive tests (+ or -)

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

“One in a million chance . . .”

Servings/hourServings/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

Replications??

Influenced by variance

More variance = More replications

Calculate sample size and power

And the answer is . . ?

Are your interventions working?

Is your investment in food safety paying off?

Does your HACCP system work?

QUESTIONS?