Data.gov has just announced the publication of one of the largest Data Sets

"Data.gov now hosts a set of Resource Description Framework (RDF) documents containing triples created by converting a number of the Data.gov Data Sets into this format, making over 6.4 billion triples of open government data available to the community."

http://www.data.gov/semantic/data/alpha

This time.. triples on food and agriculture, also.. ready to be consumed.. :-)