nutrient loss in vegetables

[Elizabeth Frazao]

I've seen some research showing that frozen or canned vegetables may
even be more nutritious than fresh ones because they are processed
shortly after harvest, when their nutrient content is highest, whereas
fresh produce may not be consumed until several weeks after harvest. 
Check out the following website:   
http://www.colostate.edu/Depts/CoopExt/PUBS/COLUMNNN/nn970122.htm

The Agriculture Research Service of the U.S. Dept. of Agriculture has
a food composition and nutrient data base.  Check out
http://www.nal.usda.gov/fnic/foodcomp  and  look for the USDA Nutrient
Database for Standard Reference - Release 13, which includes info on
nutrient retention factors.