The
Choice article doesn't say that preserved vegies have more nutrients than fresh ones. It says,
"By the time you eat them, fresh vegetables can have lower levels of important nutrients, such as vitamin C, than their frozen counterparts."
Which I would not argue with. You should have your fresh fruit and vegetables
fresh. If you do one shop a fortnight and eat your vegies only after they have turned limp in the fridge, then yes, they will do you less good than if you got some frozen ones.
But if you buy them and eat them within a few days while they're still crisp, then they'll be better for you than the frozen variety.
"We also retested the fresh vegies after storing them (uncooked) for one week in the fridge (at 4°C). They lost nutritional value in this time — especially the green vegetables (broccoli, green beans and spinach). So unless you use up your fresh veg quickly you’re better off with frozen."
I don't think you'll find any chef, professional or amateur, who'll say that vegies that have been sitting in the fridge for a week are going to be really good for you. If you went to a restaurant and asked, "are these vegies fresh or frozen?" and they replied, "they're fresh! they've been sitting in the fridge for a week!" what would you think?
Honestly, unless you're living in the outback somewhere and so must store months of food, then if your vegies are in the fridge uneaten for a week -
you're not eating enough vegies. As a couple (and about half the time, a third guest), we have a standard-sized fridge, it gets filled with vegies twice a week. 2.5 person household, 1kg fruit and vegies each daily, that's 17.5kg weekly.
Fresh is best. Fresh - not sitting around for a week. Fresh.