To my knowledge, canned veggies and fruits have very little nutritive value. Frozen is better. Fresh is best, of course. It could be the pesticides on the fruit that is making your throat itch. Try washing them in a mild hydrochloric acid solution before eating them. Put the juice of a fresh lemon and a 1/4 cup of salt in a sink or bowl with a gallon or two of water. Let them soak for a few minutes and give them a good rub. Rinse them with cold water and dry them. Better than any veggie wash you can buy in the store and much cheaper.