The biggest difference in organic vs. non-organic foods as seen by shoppers who stroll supermarket isles, is the price. This is no doubt the biggest reason not to buy. There are, upon close inspection, some slight flaws in the organic variety, especially in the fruits. And too, the skins of apples, as one example, may not be as shiny and as appealing to the eye since no polishing was done.
The reasoning behind buying organic is that the produce has been grown in soil with no potentially poisoning fertilizer added and no harmful sprays have touched the leaves. All fertilizer has been from organic sources; many of these are from fish byproducts and sea weeds. All these farms that grow organic foods commercially are inspected and supposedly are healthier.
Making the decision to switch over from non-organic to organic has to be a personal choice. I would recommend those that have immune system problems, or more specific, known allergies to ingredients to harsh fertilizers, definitely buy only organic vegetables and fruits. Others with specific problems could sporadically do their own testing.
As to taste, there probably isn’t much difference, but there is a big difference in nutrients. Taste is variable and has much more to do with how long ago the fruits and vegetables have been picked. As a past organic gardener – on a small scale – I know that from season to season some varieties of vegetables – I never grew fruits – would be more flavorful. All this had to do with the seasons and the weather more than types of fertilizers.
Tomatoes are one vegetable – or quite correctly fruit – that becomes almost inedible if the season has been a wet one. They taste much better with just the right amount of water and lots of sunshine. Melons are another whose taste depends on lots of water and exactness of nutrients. Whether the type of fertilizer makes the difference here is questionable.
As to the quality of canned or frozen organics, the difference is usually in the amount of salt of the canned over frozen in either non-organic or organic. Par-boiling the vegetables for a minute and then rapidly cooling and packaging will result in a better frozen product of either type.
It is doubtful whether the method of growing has any effect on the preservation method. At least from the standpoint of the home method; I cannot speak for the commercial variety. I would assume there is not much difference.
In the best of worlds we should all be eating foods that have been grown organically, but in this depressed economy we now live in, we must make choices differently. I would suggest, if at all possible when gardening, and this may be something all of us will have to consider doing in the future, go organic. It is far less expensive, and much healthier to both humans and to the environment.