Orange juice needs to be refrigerated because it rarely contains preservatives. Most orange juice companies use little to no preservatives in their products in order to maintain the juice's natural flavors and taste.
Preservatives are found in almost any room-temperature food or drink product to give the product an extended shelf life before it expires. Refrigeration also extends orange juice's shelf life; but when refrigeration is used in place of preservatives, the orange juice cannot be left out at room temperature. Once a refrigerated container of orange juice is opened, it lasts about 7 to 10 days before going bad.