Classifying item types without inheritance

I have a system for keeping track of items in my game. Here is the base class for items:

 [System.Serializable]
 public class Item : IComparable<Item>
 {
     public string name;
     public GameObject model;
 
     public int CompareTo(Item other)
     {
         return name.CompareTo(other.name);
     }
 }

It's worth noting that different aspects of my game inherit the item class, adding additional pieces of information that they need.

I am starting to implement a sort of metadata system so that crafting systems can use any such item as long as its classified a 'rock'. The issue I'm having is that should an object be a 'food', I need to be able to give it a food and water value, or if it's a building material I need to assign its strength.

To make things worse on myself, I don't want to use inheritance. I would like objects to be able to be both edible and a building material, for example. Additionally, my current code base relies on inheriting the base item class.

I am thinking along the lines of JSON, for example:

 stats: {
     edible: {
         food: 6,
         water: 3
     }
     weapon: {
         damage: 3
     }
 }

but I should admit forthright that I don't properly understand JSON or have any idea how to replicate it.

I'm almost convinced the solution is far simpler than I think it is, I just can't seem to figure it out. If any of you kind strangers could shed some light on this that would be outstanding.