FoodOn is compatible with the Basic Formal Ontology (BFO), which means that all the classes provided by FoodOn are organized under BFO classes, and reasoning over the ontology does not lead to BFO-related contradictions. FoodOn actually includes BFO, so when one explores the ontology from the top-down, it is a bit more complicated to see where BFO ends and FoodOn terms start. The diagrams below show the location of key FoodOn classes. FoodOn “food material” is a type of “environmental material“, which we positioned under “fiat object part” because the boundary between adjacent environmental materials may be difficult to define physically, and this carries over to edible vs. inedible parts of food entities too. (Note that “environmental material” is actually an Environment Ontology term; often a BFO-compatible ontology interweaves terms from other BFO ontologies to build one cohesive structure. BFO compatible ontologies can be found at OBOFoundry.org.)
One will also see other key FoodOn classes (many of which began as LanguaL facets) under the material entity class. Food container/wrapping, packing medium, plant structure (from Plant Ontology), food consumer group, and constituent chemicals are all found here.
(It is currently being debated whether “food product type“, which contains all of FoodOn’s 9,600+ food products, should be moved under food material.)
The “food transformation process” class is positioned under BFO “process“. Some FoodOn processes can be multi-purpose (for example, freezing can be for food preservation, or to produce an effect, like in ice cream) others are specific to preservation or other process objectives.
Observable qualities of food – the flesh texture of fish, or the colour of a fruit flesh or skin for example – are located under PATO quality (there is also a BFO “quality” class below; the two are not yet ontologically unified).
Some other information categories that are about food items are located under “information content entity“. Such information usually can’t be seen directly as qualities of a food item, but rather are legislative facts or manufacturer claims about the item.