Remember the Clean 15 and Dirty 12 when it comes to frozen fruits and vegetables too.
The advantage of frozen fruits and vegetables is that they usually are picked when they’re ripe, and then blanched in hot water to kill bacteria and stop enzyme activity that can spoil food. Then they’re flash frozen, which tends to preserve nutrients. If you can afford it, buy frozen fruits and vegetables stamped USDA “U.S. Fancy,” the highest standard and the one most likely to deliver the most nutrients. As a rule, frozen fruits and vegetables are superior nutritionally to those that are canned because the canning process tends to result in nutrient loss. (The exceptions include tomatoes and pumpkin.) When buying frozen fruits and vegetables, steer away from those than have been chopped, peeled or crushed; they will generally be less nutritious.