Calculate Time for Temperature Rise/Drop in Pipe

I need a quick and dirty method for calculating the time it takes for the temperature of a meat mixture (of which the properties I do not know, and they would change with every load) to rise from 40 to 45 degrees F.

The meat mixture is in a pipe with many bends, but I would be happy with an approximation for a straight pipe. Stainless steel 6" diameter 40S? Not 100% sure on the schedule.

Air temp outside the pipe is 90 degrees F and the meat mixture is not moving.

I want to know how long it could sit in the pipe and we could still use it.

Thanks for any help
JC