So I emailed the RDA Agricultural Data Interest Group (IGAD) mailing list and got a pretty comprehensive response from someone on that project. for those interested in ontologies for food this sounds really promising.
The full response from Valeria Pesce is publicly visible here including their proposal docs but in brief:
"aims at discussing possible alignments or crosswalks between the most authoritative classifications related to food and nutrition…
The final objective of this work is to provide a set of semantically interlinked URIs for key food product concepts as an infrastructural component that will facilitate the development of both software for actors in the food value chain and added-value integrated services that need to track food products."