Orange juice is the liquid extract of the fruit of the orange tree, made by squeezing the fresh orange. Some commercial orange juice with a long shelf life are made by drying and later re-hydrating the juice, or by concentrating the juice and later adding water to the concentrate. Others are made by pasteurizing the juice and removing oxygen from it, necessitating the later addition of a flavor pack, generally made from orange products. It is known for its health benefits, particularly its high concentration of vitamin C. It comes in several different varieties, including blood orange. In American English, the beverage name may be abbreviated as "OJ".