Nutritional Information from the USDA…
The USDA supplies a Nutritional Database. It has about 7300 foods and associated nutritional information. Most of the foods are the simplified components instead of brand names, but its usually easy enough to find equivalents. It can also be used as a jumping off point for a more comprehensive database.
Info about the information supplied: http://www.nal.usda.gov/fnic/foodcomp/Data/SR19/sr19_doc.pdf
Download here: http://www.ars.usda.gov/Services/docs.htm?docid=13746