Not GP but I like that “organic” implies that it came from a living organism. “Organic content” both carries the idea of specificity of consumption and also the idea that the content was produced by a living organism. The association maps directly onto what OP is referring to.

“Vegetarian” works insofar as it borrows the context of specificity of consumption, but only directly implies consuming non-animal products, which doesn’t map onto the OPs meaning as nicely.