sweet oranges by a mixture of lycopene and
beta-carotene and by cryptoxanthin. The
purple-red of blood oranges comes from
anthocyanins.
Citrus anatomy. The protective outer rind
includes aromatic oil glands embedded in a
bitter white pith, the albedo. Each segment, or
carpel, of a citrus fruit consists of many
delicate juice sacs contained within a strong
membrane.
The taste of citrus fruits is created by a
handful of substances, including citric acid
(so named because it is typical of the family),
sugars, and certain bitter phenolic compounds,
which are usually concentrated in the albedo
and peel. Citrus fruits are surprisingly rich in
the savory amino acid glutamate, sometimes