Bitter orange is a tall tree, up to 10 m (33 ft.) high, with darkgreen
oval leaves and flowers with five petals. The fruit has a green
epicarp that turns yellow-orange on ripening, a spongy mesocarp,
and an endocarp consisting of succulent segments. Native to the
Far East, bitter orange is cultivated extensively throughout the Mediterranean (especially Sicily), Guinea, West Indies, and Brazil:
other nations are minor producers. A commercially important variety
grows wild and also is cultivated in Paraguay. The parts used
are the leaves and twigs (petitgrain), flowers (neroli bigarade), and
peel. All oils and derivatives from bitter orange have a characteristic
orange aroma with a bitter flavor.
See Petitgrain for the essential oil from leaves and twiglets; from
flowers, see Neroli Bigarade.
Bitter orange peel essential oil can be obtained by the following
methods: (a) expression of fresh fruit rinds (peel) using suitable
machinery that ruptures the oil-bearing cells, followed by separation
and purification by centrifugation, or (b) steam distillation of
peels.
The raw bitter orange essence is transformed into bitter orange
soluble essence by washing with low-proof alcohol. The soluble
essence is used for the manufacture of special syrups and adjusted
for strength accordingly (e.g., 1:50, 1:100, 1:200, and 1:400). By
removing terpenes and sesquiterpenes by vacuum distillation or
cold extraction with low-proof alcohol, the following are obtained:
(a) terpeneless bitter orange essential oil, and (b) sesquiterpeneless
bitter orange essential oil.
The tincture (20% in 65 to 70% or 90% ethanol) and the fluid
extract are obtained from dried peels. Also see Neroli Bigarade,
Derivatives.
Prepared from the petroleum-ether-extracted concrete of bitter orange flowers. An absolute is produced by alcohol
extraction. The absolute has a very intense floral, fresh, long-lasting, delicate odor. Also see Orange, Bitter.
Aroma characteristics at 1.0%: sweet, floral, powdery, citrusy with woody floral jasmine and neroli notes.
Taste characteristics at 5 ppm: floral, citrus, tropical, rose, petitigrain, anthranilate-like with Maderia-like
nuances.
