I boiled some beets last weekend but then had to travel unexpectedly. They have been in the fridge in a container. They have some light purple watery droplets on them now. Are they still edible? Here is a photo:
It's a vegetable. When you cooked it you damaged the cell walls and the juice is leaking out.
I think this picture only seems unusual because of the beets' color. If these were carrots there wouldn't be a question because, of course, the juice would be less startling.
If these beets haven't started to mold or ferment- and you'd know it from the smell- then they are fine.
I've eaten beats that had a similar appearance with no ill effects. Let your nose tell you, as BaffledCook mentions, "if it smells like a beet", eat it.