Practical Considerations in Method Selection

1. Practical Considerations in Method Selection

2. Overview • Background • Consideration for the analysis process • Define criteria for method selection • Selection Example – Indicator tests • Summary

3. Producing Safe Food is our First Priority • Consumer Protection & Trust • Consumertrust • Food Safety is critical to that trust • Business Survival • Our brands are most important assets • Industry Responsibility • Committed to food safety across thefood chain

4. Background • Testing is used as a tool to make decisions about the general state of a dynamic system. • Pathogen testing is used as a tool to make decisions about a dynamic system that has greater public health implications.

5. U.S. Historical Perspective • Public health systems are representative of our general population shift (rural to urban • Before the 1870’s virtually all food produced and traded locally • Food mass production and transportation abilities changed quality and safety perceptions

6. Historical Perspective • Need existed to regulate the safety of food • Regulations focused on dirt • Massachusetts Health Act of 1797 • Our current public health systems are still based on these principles

7. Analysis Process

8. Business factors to consider • Customer needs • Operational Costs • Lab complexity and layout

9. Analytical Process Steps • Thinking / Planning • Sampling • Transport • Testing • Results • Decision

10. Where do we have method choices • Sampling • Transport • Prep • Microbiological • Chemical • Physical • Incubation • Testing • Data Management

11. Process Goal • Produce the best result possible • System has been optimized and the parts work together

12. Decisions, Decisions, Decisions • Conformance • Fitness for use • Communication

13. Sampling

14. What do we consider • Purpose • Quality • Safety • Investigational • Risk • Economics • How many and how much • Desired outcome

15. Sampling Considerations • Matrix • Analyte • Distribution of target in matrix • Lot size • Storage

16. Sampling • What is the matrix • Liquid • Powder • Etc. • How large is the sample • What is the container • What are the temperature requirements

17. Transportation Issues

18. Transportation – Key Parameters • Identification • Sample can be easily identified • Who • What • When • Where • How much • Preservation • Sample maintained with minimal change in intrinsic parameters • Protection • Sample is protected from external contaminants

19. Sample Attributes • Microbiological levels • Lipid • Flavor • Texture • Nutrient composition

20. What to consider in transport • Chemical composition of packaging material • Morphology of packaging polymer • Concentration of possible penetrants • Presence of co-permeant

21. Environmental Factors • Temperature • Relative humidity • Packaging characteristics

22. Preparation Consideration • Recover or measure a specific analyte • 3 factor combination • Matrix • Analyte • Test • Optimize for best outcome

23. Incubation • Microbiological or Chemical • Temperature • Motion – static or shaking • Atmosphere - air, microaerophilic, anaerobic • Optimize for best outcome

24. Testing

25. Testing • Key step in process • Success is dependent on previous steps • Requires in depth planning • Requires stringent quality systems

26. Testing Considerations • Product knowledge • Previous use • Cost and value • Analysis performance

27. Testing • Method Selection • Analyte • Matrix • Time • Money • Method Execution • Receipt • Prep • Test • Result

28. Testing - Science Based Criteria • Paramount importance to execute each of these steps well • Data used to make key public health policy decisions • Food Safety Objectives – FSO’s • Listeria in RTE products • Chemical contaminants in foods • Allergen levels • Data used to make key corporate decisions

29. Data Management

30. General Data Uses • Safety assessment • Pathogen Risk • Qualitative and Quantitative data • Quality assessment • Spoilage Risk • Product Quality • Qualitative and Quantitative data • Product and process improvement • Criteria development • Specification development

31. Microbiological Data may be Used to Assess: • The safety of food • Verification/validation procedures in HACCP • Adherence to GMP/GHP • The utility (suitability) of a food or ingredient for a particular purpose • The keeping quality (shelf-life) of certain perishable foods • Acceptability of a food or ingredient from a source for which there is not confidence in the process

32. Data Generation Assumptions • Methods validated • For specific matrix • Quality system in place for analysis • Analysts • Facility • Analysis tool • Sampling plans are appropriate

33. ApplicationExample – Indicator Testing

34. Definition of an Indicator • Webster’s defines an indicator as “ an organism or ecological community so strictly associated with particular conditions that its presence is indicative of the existence of these conditions.”

35. Definition of an Indicator Test • A test that accurately measures the organisms presence , absence or population count, thereby providing indirect evidence of a particular sample feature or condition

36. Common Indicator Tests • TVC • Coliforms • Enterobacteriaceae • Enterococci • Lactics • Yeast and Mold

37. Common Indicator Tests • Psychrophilic counts • Anaerobic counts • Group Specific Pathogen Screens

38. What is the test purpose • Distinguish good from bad • Lots • Pieces • Determine process changes • Determine process approaching control limits • Rate product quality

39. What is the test purpose • Determine inspection accuracy • Check precision of the measuring instrument • Acquire product design information • Measure process capability

40. Selection Criteria • Measures what it is supposed to measure • Measurement correlates to a desired outcome • Results are easily interpreted • Data is easy to manage

41. Selection Criteria • Simple • Deployable as close to process as possible • Walk away use • Cost Effective • Not necessarily “cheapest” • Rapid

42. Indicator Acceptance Criteria • The organisms or conditions you measure have a “strong” relationship to a particular outcome or situation

43. Test Implementation

44. Situational Assessment • Assess a problem/situation • Determine your measurement needs • Identify critical parameters • Select measurement tool that gives the best indication of significant change

45. Method Assessment • Colony counts • Direct detection • microscopy • Cellular component assessment • ATP • Physiological properties • Impedance/conductance • Metabolites • toxins

46. Test Assessment • Measurement • Protocol Development • Testing • Validation

47. Implementation and Decisions • Use the test • Collect data • Monitor the results • Test the system • Analyze the data • Use for decisions

48. Summary • The analytical process is complex • Understanding the importance of each step and their relationships are key • Confidence is built by executing all of the steps well and highlights the need for stringent quality systems and procedures throughout the process

49. Thank You !!

50. References • Juran’s Quality Control Handbook, 4th edition; Juran, J.M. ,Gryna, Frank M. • Scientific Criteria To Ensure Safe Food, Institute of Medicine, National Research Council • Milestones in Microbiology ; Brock, Thomas • Making Safe Food; Harrigan, W.F. , Park R.W.A • Evaluating The Measurement Process, 2nd edition; Wheeler, Donald J. , Lyday, Richard W