Some producers add citric acid or ascorbic acid to juice beyond what is naturally found in the orange. Some also include other nutrients. Often, additional vitamin C is added to replace that destroyed in pasteurization. Additional calcium may be added. Vitamin D, not found naturally in oranges, may be added as well. Sometimes Omega-3 fatty acids from fish oils are added to orange juice.[14] Low-acid varieties of orange juice also are available.
Juice producers generally use evaporators to remove much of the water from the juice in order to decrease its weight and decrease transportation costs.[15]
Because the process removes the distinct aroma compounds that give it a fresh-squeezed taste, producers later add back these compounds in a proprietary mixture, called a "flavor pack", in order to improve the taste and to ensure a consistent year-round taste.[15][16] The compounds in the flavor packs are derived from orange peels.[16] Producers do not mention the addition of flavor packs on the label of the orange juice.[16]