How can I reduce nitrate concentration in vegetables before or during cooking? Can someone tell me how to minimize nitrate concentration in raw vegetables before cooking them? I need this advice very much because I'm cooking vegetables for my infant son, and I've heard that high nitrate concentrations are especially toxic for infants.

Some say that soaking vegetables in salty water with ascorbic acid can help, is that true?

Also, is there some technique that allows to neutralize nitrates during cooking? Like, maybe, changing the water.
Here is a great resource for this: Nitrates, Carrots, and Homemade Baby Food.

In a nutshell, though, there really is no way to reduce nitrate content without exhaustive preparation. We're talking grinding, pressing out the juice, then heating the juice to produce leafy veggie tofu. Yuck.