Re: what is the chemical composition of coffee(regular),

You an access the "nutrient" composition of coffee from the National 
Nutrient Data Lab's web site at  http://www.nal.usda.gov/fnic/foodcomp/Data/index.html.  This 
will give you 
the composition in terms of nutrients, but natural foods have many, many 
components that will not be listed as nutrients.  Evaporation will not 
change most chemical components but could result in the loss of volatile 
components.  Mold growth in the liquid coffee and oxidation of components 
in the dry powder could result in chemical differences between wet and dry 
coffee.  You may argue that changes due to evaporation are negligible, or 
that loss of volatile components makes the dry product 
chemically different.  Aren't arguments fun!

Phyllis Stumbo

University of Iowa

Clinical Research Center