This class is in process of being defined and developed. An active 'issue' discussion is open on GitHub.
The provisional definition proposed is A physical property that inheres in a food material or one or more dietary nutritional component
This is one of the proposed classes where 'physical property' is initially suggested sensu http://purl.obolibrary.org/obo/NCIT_C158424 (Any of the characteristics that define the nature of matter or forces that act upon it) and is distinct from the proposed 'functional attribute' class. One may expect terms such as 'energy', 'specific gravity' to be included in this class.