CPG Section 585.525: Mushroom Mycelium - Fitness for Food; Labeling
The Food and Drug Administration sometimes receives inquiries about the use of mushroom mycelium produced by submerged culture propagation in various media. Mushroom mycelium is considered suitable for food use when grown in acceptable media.
However, mushroom mycelium has an identity different from mushrooms, and food products in which it is used should be labeled to clearly indicate that they contain mushroom mycelium.
Mushroom mycelium grown in acceptable media is regarded as suitable for food use. Any food in which mushroom mycelium is used should be labeled to state that fact. Labeling should not suggest or imply that the food contains mushrooms. For example, a soup in which mushroom mycelium is an ingredient should not be labeled or sold as "mushroom soup" since that name by long consumer understanding and usage is preempted by soup containing real mushrooms.
Reissued: 10/1/80, 12/8/88