Im working on on our shelf life test for our fresh meat. My question is on how to determine the "log" or how to calculate it base on my TPC (total platye counts). see below the part of email I received regarding for the requirement that we need to meet for japanese standard.
TPC Standards (Japan):
Greater than Log 8 = Spoiled
Greater than Log 7 = initial stage of spoilage
Log 6 or less = General standard for non-processed food (meat, fish etc.) at the point of sale
Log 5 or less = General standard for processed food at the point of sales
It's easy although yr email is in Japanese maths. By "Log 8" the sender actually meant the number 8.00000. Etc.
By common convention you will need a result for product "APC"/"TPC"/"TVC"/ whatever in units of cfu/gram (or maybe cfu/ml). Call it X cfu/gram
Then you need a scientific calculator with a "log" function/button. (NOT a "ln" button !)
Then, as per calculator manual for using log function, enter X and click "log" (sometimes the reverse, follow the manual)
Now compare the result to the values in yr email.
As a test check, if X = 1000 cfu/gram, the answer in calculator should be 3.000000etc
Similarly, if X = 100,000 cfu/gram, the calculator should show 5.000000etc
PS - Unfortunately the procedures/interpretations for measuring X in Canada and Japan may be different so yr data may actually be OK but not necessarily match their opinions.