1. Copyrights © 2006 Silliker, Inc. All Rights Reserved Practical Considerations in Method Selection

2. Copyrights © 2006 Silliker, Inc. All Rights Reserved 2 Overview Background Consideration for the analysis process Define criteria for method selection Selection Example – Indicator tests Summary

3. Copyrights © 2006 Silliker, Inc. All Rights Reserved 3 Producing Safe Food is our First Priority Consumer Protection & Trust  Consumer trust  Food Safety is critical to that trust Business Survival  Our brands are most important assets Industry Responsibility  Committed to food safety across the food chain

4. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved Analysis Process

8. Copyrights © 2006 Silliker, Inc. All Rights Reserved 8 Business factors to consider Customer needs Operational Costs Lab complexity and layout

9. Copyrights © 2006 Silliker, Inc. All Rights Reserved 9 Analytical Process Steps Thinking / Planning Sampling Transport Testing Results Decision

10. Copyrights © 2006 Silliker, Inc. All Rights Reserved 10 Where do we have method choices Sampling Transport Prep  Microbiological  Chemical  Physical Incubation Testing Data Management

11. Copyrights © 2006 Silliker, Inc. All Rights Reserved 11 Process Goal Produce the best result possible System has been optimized and the parts work together

12. Copyrights © 2006 Silliker, Inc. All Rights Reserved 12 Decisions, Decisions, Decisions Conformance Fitness for use Communication

13. Copyrights © 2006 Silliker, Inc. All Rights Reserved Sampling

14. Copyrights © 2006 Silliker, Inc. All Rights Reserved 14 What do we consider Purpose  Quality  Safety  Investigational Risk Economics  How many and how much Desired outcome

15. Copyrights © 2006 Silliker, Inc. All Rights Reserved 15 Sampling Considerations Matrix Analyte Distribution of target in matrix Lot size Storage

16. Copyrights © 2006 Silliker, Inc. All Rights Reserved 16 Sampling What is the matrix  Liquid  Powder  Etc. How large is the sample What is the container What are the temperature requirements

17. Copyrights © 2006 Silliker, Inc. All Rights Reserved Transportation Issues

18. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 19 Sample Attributes Microbiological levels Lipid Flavor Texture Nutrient composition

20. Copyrights © 2006 Silliker, Inc. All Rights Reserved 20 What to consider in transport Chemical composition of packaging material Morphology of packaging polymer Concentration of possible penetrants Presence of co-permeant

21. Copyrights © 2006 Silliker, Inc. All Rights Reserved 21 Environmental Factors Temperature Relative humidity Packaging characteristics

22. Copyrights © 2006 Silliker, Inc. All Rights Reserved 22 Preparation Consideration Recover or measure a specific analyte 3 factor combination  Matrix  Analyte  Test Optimize for best outcome

23. Copyrights © 2006 Silliker, Inc. All Rights Reserved 23 Incubation Microbiological or Chemical  Temperature  Motion – static or shaking  Atmosphere - air, microaerophilic, anaerobic Optimize for best outcome

24. Copyrights © 2006 Silliker, Inc. All Rights Reserved Testing

25. Copyrights © 2006 Silliker, Inc. All Rights Reserved 25 Testing Key step in process Success is dependent on previous steps Requires in depth planning Requires stringent quality systems

26. Copyrights © 2006 Silliker, Inc. All Rights Reserved 26 Testing Considerations Product knowledge Previous use Cost and value Analysis performance

27. Copyrights © 2006 Silliker, Inc. All Rights Reserved 27 Testing Method Selection  Analyte  Matrix  Time  Money Method Execution  Receipt  Prep  Test  Result

28. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved Data Management

30. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 32 Data Generation Assumptions Methods validated  For specific matrix Quality system in place for analysis  Analysts  Facility  Analysis tool Sampling plans are appropriate

33. Copyrights © 2006 Silliker, Inc. All Rights Reserved 33 Application Example – Indicator Testing

34. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 36 Common Indicator Tests TVC Coliforms Enterobacteriaceae Enterococci Lactics Yeast and Mold

37. Copyrights © 2006 Silliker, Inc. All Rights Reserved 37 Common Indicator Tests Psychrophilic counts Anaerobic counts Group Specific Pathogen Screens

38. Copyrights © 2006 Silliker, Inc. All Rights Reserved 38 What is the test purpose Distinguish good from bad  Lots  Pieces Determine process changes Determine process approaching control limits Rate product quality

39. Copyrights © 2006 Silliker, Inc. All Rights Reserved 39 What is the test purpose Determine inspection accuracy Check precision of the measuring instrument Acquire product design information Measure process capability

40. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 41 Selection Criteria Simple  Deployable as close to process as possible  Walk away use Cost Effective  Not necessarily “cheapest” Rapid

42. Copyrights © 2006 Silliker, Inc. All Rights Reserved 42 Indicator Acceptance Criteria The organisms or conditions you measure have a “strong” relationship to a particular outcome or situation

43. Copyrights © 2006 Silliker, Inc. All Rights Reserved 43 Test Implementation

44. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 45 Method Assessment Colony counts Direct detection  microscopy Cellular component assessment  ATP Physiological properties  Impedance/conductance Metabolites  toxins

46. Copyrights © 2006 Silliker, Inc. All Rights Reserved 46 Test Assessment Measurement Protocol Development Testing Validation

47. Copyrights © 2006 Silliker, Inc. All Rights Reserved 47 Implementation and Decisions Use the test Collect data Monitor the results Test the system Analyze the data Use for decisions

48. Copyrights © 2006 Silliker, Inc. All Rights Reserved 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. Copyrights © 2006 Silliker, Inc. All Rights Reserved 49 Thank You !!

50. Copyrights © 2006 Silliker, Inc. All Rights Reserved 50 References Juran’s Quality Control Handbook, 4 th 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, 2 nd edition; Wheeler, Donald J., Lyday, Richard W