From Distillers Wiki
Orange juice is the liquid obtained by squeezing or pressing the interior of an orange. It is enjoyed as a beverage in many parts of the world. It is sometimes referred to by the abbreviation "O.J."
The largest exporter of orange juice is Brazil, followed by Florida. Orange juice is commonly exported in dried form and infused in the destination country. Juice which is shipped in liquid form is traded as "direct juice" between producers. It is sold to consumers (in the USA) with the label 'Not from Concentrate'.
Fresh orange juice generally has a fruity and pleasantly acidic taste. It contains a high amount of vitamin C (ascorbic acid). Some manufacturers add citric acid or ascorbic acid to their products, in addition to other nutrients such as Calcium and Vitamin D.
Frozen Concentrated Orange Juice (FCOJ) is a commodity product traded on the major commodity exchanges, including the Chicago Mercantile Exchange (the 'merc', pronounced 'merk') and the New York Mercantile Exchange.
When water is added to freshly-unfrozen FCOJ, it is reconstituted. Almost all orange juice sold in the United States is reconstituted juice, since there is a huge difference in the volume of FCOJ and unprocessed juice and this makes a difference in the price the consumer is charged.
There is some legitimate disagreement about the quality of fresh-squeezed juice versus juice that has been processed into FCOJ and reconstituted. However, while it might seem that FCOJ would reduce the 'freshness' of the juice, unprocessed juice may be significantly less tasty due to fact that the time it takes for juice to be squeezed, bottled/packaged, and delivered to the consumer might reduce the flavor just as much as the concentration / freezing process.
Orange juice also contains a surprising amount of methanol (wood alcohol). In a 1993 study by the UK Department of Health, some orange juice was found to have as much as 420 mg/kg of methanol. (By contrast, this is about 50 times the methanol present in a sugar wash).