Not all, but yes, some components are inevitably lost in the drying process. There’s a reason that dried fruit is often treated with sulphur dioxide as a preservative. Of course, preserving the colour doesn’t prevent the loss of large amounts of essential nutrients like vitamin C. Fresh is best whenever possible.

Doesn’t need to be a desert. Anywhere that has a dry season with lower humidity should work regardless of total annual precipitation.

And borax, to keep the termites from eating it.

One more reason to move to the jungle.

Just be to sure to check for rotten spots in an old wooden barrel before setting it up! Old wood + constant moisture = fungal rot.