I use supermarket apple concentrates a lot, as i have no access to apples or a press and there are no home brew shops close, I find them very convenient and if u check the labels, by law (at least in the uk) any preservatives must be included on the label, however most in the uk at least don't have anything in them that detracts from fermentation, this applies to all supermarket juice, so, I personally enjoy making wine from any litre juices you can get from a supermarket, from grape to apple, to mangos, anything basically.
Most canned fruit can be fermented as well.
One other thing is, different makes of the same juice type eg apples have differing results in flavour, but, as a rule if u have bit of a sly taste before u make your wine with apples for eg you can tell the predominant flavour for example red or green apples, as obviously they will produce a differing end result.
addendum if the preservative is stated as citric acid, that's fermentable as well, because citric acid is a home brew additive, its basically what`s in lemons and a lot of country wine, home brew recipie`s include lemon as an ingredient.