Water activity: disposable sample cups

Hello everyone!

Quick question, I test the water activity in our chocolate gauche as a quality control point.

We currently purchase disposable sample cups, clean them, and reuse them.

I questioned this method and began researching if you can/should reuse them. After not finding any cleaning producers or mentioning of reusing, I called the supplier. They stated the cups are made in a sterile environment for a one-time use and the accuracy of the system depends on sterile sample cups and washing is not recommended.

To help gain buy-in, can anyone supply documents which states or proves why you can't simply wash, dry, and reuse sample cups?

I'm being asked, if the sample cup is dry, what's the difference in reusing it vs. using a fresh one.

Thank you!

Michael

It would be a best practice to use a new one.   It is the manufacture recommended practice   there is the opportunity for skewed results for using a unclean / non-dry cup.  

Scientifically, I agree with you.   A clean dry cup should produce the same results as a new cup.   I cant think of a scenario where it might not.  

Their argument that they need to be sterile does not make sense.  Once opened, they are no longer sterile.   

Assuming that your sample is disposed of, I can't see why you cannot reuse, it is after,  only water activity your testing

Alternatively, why not buy some proper lab glass that can be properly cleaned and sanitized with an alcohol dip

Assuming that your sample is disposed of, I can't see why you cannot reuse, it is after,  only water activity your testing

 

Alternatively, why not buy some proper lab glass that can be properly cleaned and sanitized with an alcohol dip

I don't believe the testing system is glass compatible with my Rotronic unit, and must use Rotronic sample cups.

Take some ATP swabs to see if there is any variation.  You risk contaminating your product when reusing a non-sterile cup.