1. Have binoculars in hands, zoomed in.
2. Go into inventory, choose a zucchini, choose "Eat All".
3. As soon as the action is complete enough to allow it, put the binoculars back in hand and zoom in to observe something.
4. Wait a few seconds, when the final "you have finished eating all zucchini" type message shows your binoculars should disappear and the zucchini will still be in your inventory.
... or at least that's what happened to me!