I would agree with Antdrew on just not taking risks. While also saying, i feed my ants a bit of fruit slice sometimes.
I'd say this is a situaiotn where no one should really encourage anyone to take an unnecessary risk with their ants. We have no real control or guarantees when using commercially produced fruits, so the general given advice is right to say,
"don't do that, it's a risk you have no need to take, just use commercially produced ant nectar or your own sugar water mix."
You can however take on all the risks you peronally want to take on, just best not to give it as "good advice" to other people.
I only use organic, and i wash it well, and i've not had any bad incidents. But it is a risk and i'd not suggest others to do it.