I sometimes use dehumidifier water because I have well water that gets ran through a softener. It beats soft water because of its added salts, and sometimes I don't feel like filling a bucket from the outdoor hose or bathtub which is outside the softeners water line.
The only thing I've ever heard of as a concern is the way that dehumidifiers gather water. From what I read, they use copper coils and other metals to condense the water out of the air. The concern is that trace amounts of these metals can be transferred in the water.
In fish, I read it was causing mutations for people that used the water in their tanks. I read no posts on it being harmful to plants directly, but none of those talked about fruiting plants to be used in human consumption.
(rep+ if this post helps. I'm new here)