[ZenGum]

"Fresh" veggies from supermarkets are very rarely really fresh. Most often they have been in storage at 1-4 degrees C for a week or two, even more sometimes, and often with special gases (in low concentrations) to delay aging.
Frozen veggies are usually frozen within a day or less of harvest and, surprisingly, often arrive at the dinner table with more nutritional content than "fresh".
However, freshies from your own garden or a local farmers' market ... that's the way to go , if you can manage it.