Is there a device that is able to test cooked meats to determine when
or how long ago the meat was cooked e.g test for how long it has been
standing for since cooking?

stoners-ga:

In order for such a device to be usable, there would need to be a
property of the cooked food that changes with time following a known
or trackable model. This could be something such as the rate of growth
of bacteria on the surface of the food, or the temperature drop rate,
or even the rate of decay in intensity of the odor emitted.
Unfortunately, I think there are simply too many input variables
involved in these models, for any instantaneous measurement device
(ie. one that takes a measurement at some point in time after the
cooking is done) to be able to work. So, the only device that can
accurately measure how long food is left standing after it has been
cooked, is a timer that is started (manually or automatically) once
the cooking is done. I suspect that is not what you are looking for in
your answer, though, so I post this here as a comment in the hopes
that one of my fellow Researchers can prove my thinking wrong, and
discover a device that will do what you are looking for (and that is
not a simple time-keeping device!).

Regards,

aht-ga
Google Answers Researcher

Yes there is an instrument.  I know of two.  The first is called an
NIR (Near infrared) Spectrophotometer.  I used to sell NIRS devices
and we used them in the food industry to meaure many complex food
properties.  One fun one I remember was predicting whether a cake mix
would test good without cooking the cake.  The only difficulty you
will have is calibration.  For example if you are testing pork, you
will need to get about 30 samples of various ages and present it to
the device and inform it that it is looking at say 1 hour old, day
old, 3 day old etc.

The device will provide you with a report that tells you how well it
can relate test data to your known sample set.  This will give you a
confidence indication.     After calibration you give it some samples
and let it tell you the results.  Also you will most likely need
sample sets for different variation of meats and make sure you present
the sample to the instrument at the same temperature and conditions.

A flash freeze and grinding the meat to a powder may work. 
Alternately, you may go the other extreme and attempt to liquify in a
solvent and present it in liquid form.

Please be prepared to break out the check book. There are several
firms making these devices and I wouldn't buy one that was under $15k
and be prepared to work with it with a lot of samples to know for sure
if you got it working right.

They were buggers to sell, so the firms that offer them will many
times give you a loaner model to see if it works.

The second and perhaps more accurate device is the nose.
Regards, Phil

You could use a wipe and count the bacteria on a swab as bacteria
mutiplay at a known rate this would tell you how long the food has
been out, there are Medical devises capable of doing this