Re: What ways can you test for Iron in meat.

Dear Dianne,

The storage conditions that meat undergoes should not affect
the overall iron content.  Unless the meat is very fresh and blood seeps
from the surface, thereby producing a loss.

If you are thinking of the color change that meat undergoes during storage,
that is due to oxygen absorption and also a change in the oxidation state 
of the iron contained in the blood hemoglobin and the myoglobin contained 
in the muscles.  A fresh cut surface will exhibit a purple-red color.  By 
absorbing oxygen from the air, the surface will turn bright pink, 
typical of the fresh meat seen at the butcher shop.  
After some time, the oxygen will react with the iron to change from a 
reduced state (Fe2+) to an oxidized state (Fe3+), producing the kind of 
brown color seen when a piece of meat sits refrigerated for a day or so.  
The reaction scheme is reversible, unless nitrites are added to the meat 
which keeps the nice red color for a much longer time.

Myoglobin (purple-red) + Oxygen ==>  Oxymyoglobin (bright red-pink)

Oxymyoglobin + loss of an electron (oxidation)  ==> Metmyoglobin (brownish)

An excellent reference to look up is
“Meat Curing Principles and Modern Practice”  R.E. Rust and D.G. Olson, 
Koch Supplies, Kansas City, MO  64108  ©1973.

Now, your question directly asks for methods of testing the iron in meats.
The way that food manufacturers would analyze for iron would be to dissolve
the meat in strong acid, and then use an atomic absorption 
spectrophotometer or an inductively coupled plasma spectrophotometer to 
analyze the iron content.  As these instruments are tremendously 
expensive, a better way for you to try this analysis is by using aspirin.  
Yes, aspirin!
Iron will react with aspirin to form a purple color.  The relative amount 
of purple color is proportional to the iron content.  It is important to 
use enough aspirin to make sure that all the iron reacts.
So, you will need to get some soluble iron salt like iron chloride or iron
nitrate.  Make up a series of concentrations of this salt in water.  Also 
make a strong solution of aspirin by dissolving 8 or 10 tablets in a small 
amount of hot water.  Use a specific amount of the aspirin solution by 
using a pipette or by counting the number of drops necessary to cause no 
further increase in color.
Mix the two solutions and you will wind up with a series of test tubes 
that range from light purple to dark purple.  If you have access to a 
spectrophotometer, you would want to measure the light absorption of each 
solution.  This is called making a standard curve.  
If you do not, then you will have to compare the samples 
(from blended up meat) with your standards.  Remember, these solutions 
will not be stable for too long, so you will have to do this every day.
Your library should have a textbook suitable for a college sophomore class 
in quantitative analysis.  Almost everyone of these has some type of 
experiment similar to this.  
The correct term for this chemical analysis is “Colorimetric Analysis”

I hope this is what you were looking for.

Dr. Mike Gallagher
Senior Research Chemist
J.R. Simplot Co.