How do you make powdered lemonade concentrate from fresh squeezed lemons?

I am not sure if this is possible as I don't believe that powdered lemonade is actually from squeezed lemons.

You could do a wet concentrate, I believe you would do it the same way that you would make any fruit juice concentrate from fresh juice.

You would place the juice in a vacuum, as pressure is is reduced the boiling point for the water in the juice will be reduced, thus requiring lower temperatures to evaporate the mixture.

Then heat would be applyed as well.

But I assume that if you tried to reduce all the moisture to the point that it was a powder with this method, I would assume that you would damage the sugars in the concentrate until their is nothing left of them except some bad tasting hydrocarbon sludge.

But I am not positive about this, I guess the simpliest backup I can think of for my argument is, is there a powdered Orange Juice concentrate?

The first thing that comes to mind for me would be Tang, and for anyone that has tasted Tang it is apparent that the main ingredient is not from orange juice.