Oranges, whose flavor may vary from sweet to sour, are commonly peeled and eaten fresh or squeezed for juice.
The outermost layer of the rind can be thinly grated with a zester to produce orange zest. Zest is popular in cooking because it contains oils and has a strong flavor similar to that of the orange pulp. The white part of the rind, including the pith, is a source of pectin and has nearly the same amount of vitamin C as the flesh and other nutrients. Although not as juicy or tasty as the flesh, orange peel is edible and has significant contents of vitamin C, dietary fiber, total polyphenols, carotenoids, limonene and dietary minerals, such as potassium and magnesium.
Orange juice is obtained by squeezing the fruit on a special tool (a juicer or squeezer) and collecting the juice in a tray underneath. This can be made at home or, on a much larger scale, industrially.
Sweet orange oil is a by-product of the juice industry produced by pressing the peel. It is used for flavoring food and drinks and also in the perfume industry and aromatherapy for its fragrance.
Marmalade preserves are traditionally made with Seville oranges, which are less sweet. All parts of the fruit are used: the pith and pips (separated and placed in a muslin bag) are boiled in a mixture of juice, slivered peel, sliced-up flesh, sugar, and water to extract their pectin, which helps the conserve to set.