I don't have any direct experience with strawberries, but am in ag and have been in some trainings with some of the strawberry growers around me.
In the U.S., strawberries are generally field-packed. If that is your case, it is a question of training for your pickers and a good QA program to hold them accountable. If you want to see one of the best end-to-end traceability programs out there, google Wish Farms out of Plant City, FL. They fresh pack in the field, but use a picker specific barcode on each container (pint in the U.S.) so that they can identify the picker who packed a specific package if needed. They offer the pickers an incentive program using this methodology, but it also allows them to also identify which picker isn't following their procedures during any QA inspections.
In you are packing in a packing house, then for strawberries, I would google for scientific studies on the best methodologies to handle the product. Strawberries are delicate; perhaps a water tank where the product can float through while foreign materials sink. If it were me, I would fresh pack with a strong personal sanitation program (supervisor verifies washing of hands, etc.) , QA inspection process and would be treating my AG water as that (along with the pickers) would be my most likely sources of contamination.
Anyway....
Good luck,
Todd
