By and large, the most important processed citrus fruits product is orange juice. It is measured in brix degrees value, which is a measure of concentration of solids and of the sugar/acid ratio
(See Citrus Reference Book, Conversions and Equivalents).
Orange juice can be presented in different forms. The major types of orange juice are the following:
•Freshly Squeezed Orange Juice
The juice is squeezed from fresh fruit and packaged in paper cartons, glass or plastic containers, without being pasteurized. The product is clearly labeled and located in the produce or dairy section of the grocery store, with a shelf life of only a few days. It is also typically made at home. Traditionally, an important proportion of European orange juice consumers has preferred to freshly squeeze oranges at home.
•Frozen Concentrated Orange Juice (FCOJ)
Frozen Concentrated Orange Juice (FCOJ) is the most widely traded as a commodity in the international market, normally at 65º Brix. FCOJ is obtained by removing, through evaporation, the water from the orange juice of fresh, ripe oranges that have been graded, sorted, washed and squeezed in extraction machines. It is then stored at 20ºF or lower until it is sold or packaged for sale. FCOJ is seven-to-one strength ratio to normal single-strength orange juice.
Consumers reconstitute the FCOJ at home by adding water to the concentrate. At one time this used to be the dominant type of orange juice sold in the United States. However, due to increasing consumer preference for more convenient ready-to-drink orange juice, FCOJ has lost its supremacy.
FCOJ can be stored for several years at the adequate temperature.
The process of obtention of FCOJ is illustrated in the following chart: