Survival protocol for unknown fruits and berries is to rub a small amount on your bottom lip and wait a while. Then ingest a small amount and wait a while. Increase amount you're eating while monitoring effects and 'output'...

Please note, this is not professional advice - if you try this and die or spend 9 days on the throne I'm not responsible. It's a survival technique, intended for use when not eating anything will kill you, while eating the wrong thing might kill you.