I wasn't sure if anyone could shed some light on a pathogen testing question. Throughout the years I have had many products tested. When doing Salmonella, generally the result is reported as "Not Detected per 25 g". The new company I am working with is processing a dry hot cocoa product. The lab seems to always run into issues with presumptive positives for Salmonella, and end up reporting "Not Detected per 375 g".
Does that mean we are just using a larger sample size, or does this mean I have a bigger issue. When your spec to customers says "not detected per 25 g" it creates a red flag.
I appreciate any information or insight that anyone can offer.
The different reporting may be real caused by changes in lab sampling procedure due, for example, to (a) variations in customer requirements, (b) specific Regulatory requirements, © lots with known sampling difficulties, etc. Or, sometimes, the differences may be caused by semantics ie inaccurate reporting of results,
In "basic" lot sampling, the typical, single sample size taken from a given lot is 25 gram. This is analysed for the presence of salmonella and a negative result is reported as "Not detected in 25 gram".
However BAM Salmonella sampling procedures require 15 or more samples (each 25g) to be taken from a given lot, ie >= 375gram. The total amount is then to be analysed and a negative result would be reported as "Salmonella Not detected in 375 grams". However, regardless, some labs may "standardise" on a "Not detected in 25gram" reporting style.
So yr confusion may relate to the specific analyses/labs involved ?
PS - you may find these sort of related Salmonella threads interesting -