Harvest & Post-Harvest
Post-Harvest Microbial Sampling & Test Interpretation
Microbial test results describe the sample and method used. A useful sampling plan must account for lot heterogeneity, visible suspect material, laboratory method, jurisdictional requirements, and how results will change disposition decisions.
Key concepts
- Microbial populations can be uneven within a lot
- Different analytical methods may detect or quantify different targets
- Total counts do not necessarily identify each organism present
- Visible mold and laboratory counts are different types of evidence
What to measure or observe
- Define a representative sampling plan before collecting samples
- Keep sample identity and chain of custody
- Record laboratory method and target organisms
- Interpret results against the applicable specification rather than an unrelated threshold
Common mistakes
- Submitting one convenient flower as the entire lot
- Assuming a total count reveals the species present
- Mixing visibly suspect material into the sample only after a problem is noticed
- Comparing results from different methods as if they were identical
Visuals this lesson still needs
- Representative microbial sample plan
- Sample-to-lab chain of custody
- Total count versus organism identity
- Result-to-disposition flow