The real issue here is the oxidation reduction potential of the fruit/ vegetable. Naturally the fruit in the tree has no oxidation reduction potential (ex.:-200 mV measured with an ORP-meter) , but during the process from the picking to canning and then until one is eating it the ORP value becomes positive, thus exists (per ex.:+100 mV, or more). No one likes or wants to eat oxidated food unless it has no other choice or prefers some compensative benefits e.g. :lots of calories in a small bite, excellent taste, and low price for the taste and calories intaken.The down part of this oxidation reduction potential of the food is that after ingestion will contribute to oxidation of the tissue or food around it! This impacts in two directions, in the long run:
1)increase the aging process and
2)lower the imune system with very unpleasant side effects , mainly for the erderly persons.
PS:There is an electronic device (ORP meter or REDOX metre ) that can establish how much Oxidation Reduction Potential has your canned product (100…250 mv). The fresh fruit / vegetable (just picked) will have -150 to -350 mv, depending the type.