Greetings again. Here is the response from my microbiologist and for reference his advisor is a Clemson professor:
It is not required to have accredited laboratory to conduct the shelf life studies but it is required to have an institution like company or university. I asked my advisor long time ago about if we make a research in <redacted> laboratory which is not accredited yet, Can we publish the data in international journals of food science? He said, Yes, as long as you do the research 3 replications and you triplicate the test to get 3 results to be statistically good and the research is released from an institution (like <redacted> Inc.). Then, you can publish the research in international journal of food science. That reflects that we can do it without accreditation.
I am attaching my advisor email so you can check what he said when I asked him.
Thank you,
Best regards,
<redacted>
So for shelf life studies it seems there is no direct requirement. However, an auditor may ask to see your shelf life data to see how you came up with your shelf life information. So at specific intervals you will want to perform your tests and record all of that data whether it be just organoleptic or actual testing. We have a micro lab so we do APC, Yeast, Mold, Coliform, etc.
I hope this helps you and feel free to ask further questions.
Regards,
Mr. I.