Alissa Hamilton explains in her new book Squeezed.
The book starts with the fascinating history of the orange industry in florida; it was not a juice industry until after World War II, when processors finally figured out how to make frozen concentrated juice that actually tasted good. This was the field of Minute Maid, owned by Coke since 1960. It wasn't a lot of work, adding three cans of water to one can of frozen concentrate, but it was too much for most Americans, so they started reconstituting it and packing it in boxes which were put in the cooler, right next to the much more expensive Tropicana pasteurized juice. Both had all kinds of allusions to Florida on their boxes and Florida addresses, but much if it was Brazilian, and in fact the processors in florida were sold to Brazilian firms.
After a bruising fight with the FDA in the early sixties, it was agreed that anything called "Pure Orange Juice" coudn't have anything in it that wasn't made from oranges. But they stopped there and technology didn't; now "orange essence" and orange oil is squeezed out of the peels and reprocessed by the flavor enhancing companies. The so-called natural orange juices is flash-pasteurized, then "de-aerated" so that it won't oxidise, stored in huge tanks, re-aerated, repasteurized, and re-enhanced with "flavor packs" to taste what they think it should have tasted like. In Brazil, they are building huge aseptic supertankers to carry the stuff around the world.
And then we circle around to the carbon footprint again; the cost of transporting and storing the Tropicana NFC juice is probably five times as high as frozen concentrate, now almost entirely Brazilian, and a lot higher than recon, or reconstituted concentrate, the one for the person too lazy to add water.
In the end, the only orange juice that comes off well is the fresh squeezed that you get at the stands and in the stores from local growers, who are getting into squeezing their own high end brands, and that only works in Florida.
Otherwise, I recommend you find a good local cider mill.
The writer of this book is an academic, and at times it can be a bit dry. But if you have any interest in knowing where your food comes from and why it is what it is, it is for the most part a juicy story.
More on Squeezed
And TreeHugger Scoop on OJ