Whether or not you should peel fruit and vegetables before you dry them depends on a variety of things: how you plan to use the finished product, where the fresh fruit came from, and the quality of the peel.
If you plan on using the dried fruit for snacking and just eating "out of hand", it not important to peel the fruit or vegetable first. However, if you plan to use it in your baking, for pies, breads, cookies, etc., then the peeling might interfere with the quality of the finished product. We have found that when preparing older, larger zucchinis for later use in breads and cakes (we usually shred them) that it is essential to peel them first. The toughened peeling does not reconstitute well. Also, keep in mind future use as you decide how to cut the fruit or vegetable, whether to slice, dice, shred, etc. You might want to prepare a fruit or vegetable several different ways.
The peeling offruits and vegetables contains many valuable vitamins and minerals. AT the same time, the peel absorbs much of the pesticides and chemicals used in growing and storage of produce. If you are concerned about the effects of these chemicals on your health, we recommend discarding the peels of produce that are not grown organically.
When using produce withtough, roughened skin, discard the peelings. Remember with some delicate fruits or vegetables, such as tomatoes, the skin is important to the integrity of the fruit and should be left on. Throw away any blighted or bug infested peelings, it will detract from the looks and perhaps the taste of the finished product.