Cold expression

Castor oil may be obtained by cold expression of the decorticated seed. The oil is steamed under vacuum to eliminate odors and coagulate the toxic albumin. Fuller s earth or activated charcoal may be used for further purification. 

Bergamot. Bergamot oil is produced by cold expression from peels of fmits from the small citms tree. Citrus bergamia. The fmits are inedible and of httle value. Bergamot is grown mainly in southern Italy and northern and western Africa. The oil is used to impart a sweet freshness to perfumes. Its largest chemical constituent, to the extent of 35—40%, is linalyl acetate [115-95-7] (1), with a much smaller amount of citral [5392-40-5] (2) as an important odor contributor. 

Both hot and cold express different degrees of thermal energy and are directly related to each other. The decision of what is hot or cold is a subjective choice. Heat (energy) always transfers to cold (lack of energy). So, whichever object is... 

The bitter orange essential oil is very high, up to 90% in the monoterpene limonene due to its extraction by cold expression. Concern about the use of this oil in high concentrations is due to reported cases of contact dermatitis caused by the limonene levels. It is often used as a starting material for the isolation of natural limonene. 

Lemon is an evergreen shrub or tree native to the Far East it was introduced to the Mediterranean regions at the time of the Crusades. The leaves, fruits, and rind are used either whole or pressed in foods and in liquid or solid pharmaceutical products. The essential oil of lemon is obtained by cold expression. Approximately 40 constituents have been identified, with 90%o being limonene. Fluid extracts and tinctures are obtained from the dried peel. 

Castor oil is the fixed oil obtained from the seeds of Ricinus communis (castor) by cold expression. The whole beans contain a variety of substances that are not expressed with the oil, including the toxin ricin (6,7). 

Almond oil consists chiefly of glycerides of oleic acid, with smaller amounts of linoleic and palmitic acids. The PhEur 2005 describes almond oil as the fatty oil obtained by cold expression from the ripe seeds of Prunus dulcis (Miller) DA Webb var. dulcis or Prunus dulcis (Miller) DA Webb var. amara (DC) Buchheim or a mixture of both varieties. A suitable antioxidant may be added. 

In order to get oil from citrus fruits, such as oranges, lemons or tangerines, cold expression is preferred, due to the thermal instability of the main constituents of the essential oil. The oil cells are located below the epicarp surface. The fruit must be washed and sliced into two halves, the pulp withdrawn and then the peel must be softly pressed to break the oil glands, which can be removed with water. 

Citrus bergamia, a small tree native to tropical Asia, now extensively cultivated in the Calabrian coast in southern Italy. Bergamot oil is obtained by cold expression of the peel it is also known as expressed bergamot oil from which rectified or terpeneless bergamot oil is produced by vacuum distillation or by selective solvent extraction, or by chromatography (arctander). 

Bitter orange oil is obtained from the fresh peel by cold expression in about 0.15% yield, by machine or hand. Its major producers include Guinea, southern European countries (especially Spain and Italy), Brazil, and the West Indies. The Guinean and Spanish oils are considered of the best quality. 

Sweet orange oil, commonly known simply as orange oil, is obtained by one of the three major methods (1) cold expression (hand or machine) of the fresh peel, (2) steam distillation of the fresh peel (either already expressed or not yet processed), and (3) distillation of the essences recovered as a by-product in the manufacture of orange juice concentrates. Major producers of cold-expressed sweet orange oil include the United States, Cyprus, Guinea, Israel, and Brazil, while the United States is the major producer of the distilled sweet orange oil. 

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