ORANGE LEAF, ABSOLUTE

Description

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.