Fresh is always best, if you can find it, the nutritional value is
at it’s greatest. You can blanch and freeze many firm vegetables
such as peas, green beans. Most berries can be frozen after
washing without blanching. If you can’t get fresh, frozen is your
next best. Most frozen fruits and vegetables are flash frozen
(IQF) which retains a good structure when thawed and they
keep most of their nutritional value. Canned fruits and
vegetables are a staple food for most of us. They will have
some nutritional loss during the canning and cooking. To
prevent any more loss, just heat, season as desired and serve.
Do not cook for long periods or your health benefits have been
cooked away. Check the salt content in canned vegetables and
the sugar content in canned fruit these can be very high in some
brands.