I’m curious because I just noticed a pressure cooker can cook pre soaked beans in just 5 minutes vs over an hour boiling.
I don’t think you lose nutrients from boiling. It’s mostly a texture thing; they “explode” more in the pressure cooker. Unless you’re tossing the water there’s no loss of nutrients either way.
You may be thinking of a very old study which said veggies lose nutrients when cooked in the microwave. What they failed to disclose (or maybe people just ignored) was they microwaved a very small amount of veggies in like a cup of water, and then tossed the water smh 🙄