Terpeneless oils

Component CAS Registry Number Stmcture number Distilled oil, % Terpeneless oil, %... 

TERPENELESS OIL. An essential oil from which the teqoene components have been removed by extraction and fractionation, either alone or in combination. The optical activity of the oil is thus reduced. The terpene-less grades are much more highly concentrated than the original oil (15—30 times). Removal of terpenes is necessary to inhibit spoilage, particularly of oils derived from citrus sources. O11 atmospheric oxidation the specific terpenes form compounds that impair the value of the oil for example, d-limonene oxidazes to carvone and y-terpinene to p-cymene. Terpeneless grades of citrus oils are commercially available. 

The term folded oils refers to concentrated oils. This typically involves a distillation process however, alcohol washing can also be used. Alcohol washing is based on the insolubility of d-limonene in 60% to 70% ethanol. These processes predominately remove terpene compounds, although aldehydes (octanal) are also reduced. Oils that are more than 20-fold concentrated are called terpeneless oils and are more stable. Distillation is predominately used by flavor houses. Flavor houses purchase cold-pressed oil, which is concentrated and fractionated. These fractionated portions are sold for flavorings or flavor precursors. 

Many other processes can be applied to concretes, absolutes, resinoids, and essential oils to obtain products with special characteristics. For example, decolorized products may be obtained by extraction with appropriate solvents to eliminate highly colored components. Colorless products may be obtained by fractional molecular distillation under vacuum. Yet another type of product is obtained by vacuum codistillation using a suitable solvent. Many essential oils, particularly citrus oils, contain high levels of insoluble terpene hydrocarbons, which can be removed by fractional distillation or by countercurrent extraction to produce concentrated or terpeneless oils. 

Citrus oil dominates this class of essential oil. It is obtained by the cold press method with the exception of lime oil, which is also prepared by steam distillation of essential oil separated during the production of juice.106,107 Aside from bergamot, these oils are primarily monoterpene hydrocarbon mixtures of which (if)-limonene (3) is usually the dominant compound. Since odor contribution of this monoterpene compound is low, it is often removed by distillation or repeated solvent extraction. The resulting oil rich in odor-active compounds is called terpeneless oil and is used extensively. In the case of bergamot and lemon oils, psoralen derivates like bergaptene (64) causing photosensitivity are problematic, and those for fragrance use are rectified to remove it (Table 8). 

Essential oils boil at elevated temperatures, but many cannot be directly distilled without decomposition. Vacuum, steam, and fractional or molecular distillation are often used for their manufacture. Fractional distillation removes traces of water, resinous materials, colors, terpenes, and sesquiterpenes from the distillate. This process improves solubility and enhances flavor intensity. Sesquiterpeneless oils are more soluble than terpeneless oils because of the removal of head and tail fractions (e.g., waxy residues). Most common sesquiterpeneless oils used in the pharmaceutical industry include oil of orange and oil of lemon. 

See terpeneless oil. Further information can be obtained from the Essential Oil Association of U.S. 

Citrus fruits contain peel oil, the essence from which oil is obtained during concentration of the juice process. Citrus oils are characterized by a high percentage of terpene hydrocarbons (limonene, C10H16), which contribute little to aroma. The unique characteristics of limonene are its relative insolubility in dilute alcohol and its susceptibility to oxidation, causing off-flavor production. If the monoterpenes are removed, the resulting oil is called terpene-free or terpeneless oil. Aldehydes, esters, and alcohols are the main contributors to the aromas of citrus oil. These compounds are relatively polar and soluble in water therefore, they are satisfactory for applications in food and beverage. 

Perfume materials obtained in this way are referred to as essential oils. Thus, for example, the oil obtained by steam distillation of lavender is known as the essential oil of lavender, or lavender oil. Sometimes, the monoterpene hydrocarbons are removed from the oils by distillation or solvent extraction to give a finer odour in the product. The process is known as deterpenation and the product is referred to as a terpeneless oil. This is, of course, a misnomer since, for example, the major component of lavender oil terpeneless is linalyl acetate, a monoterpene. 

VI. Terpeneless Oils. Terpeneless Oil of Lemon, Tables of sp.-gr. and Rotn. of several Terpeneless Oils, Terpeneless Oil of Orange, Ditto of Caraway, of Lavender, Table of. sp.-gr. and Rotn. of Commercial Samples of Oils.—VII. The Chemistry of Artificial Perfumes. Vanillin, Coumarin, Fleliotropin, Aubepine or Flawthorn, lonone. Specification of Patents for Preparation of lonone, for Artificial Violet Oil, Artificial Musk, Specification of Patent of Musk Substitute, Artificial Neroli, Artificial Lilac, Artificial Hyacinth, Artificial Lemon Oil, Artificial Rose Oil, Niobe Oil, Bergamiol, Artificial Jasmin Oil, Artificial Cognac Oil.— Appendix. Table on Constants of the more Important Essential Oils.—Indexl... 

The percentage of terpeneless oil obtained by careful fractionation is an indication of the value of the oil. 

The distilled oil contains a small concentration of coumarins compared to the cold pressed oil. Rectified (terpeneless) oil contains a lower concentration of terpene components than the expressed oil and no coumarins (arctander). ... 

Terpeneless Lemon Oil. Use 10 g for the determination of aldehydes. Dalton found the aldehyde ester ratio for genuine terpeneless oil to be 5 2, any considerable deviation from this pointing to adulteration. The genuine oil should not be soluble in 75 per cent alcohol. 

G. Bergamotteol R essence de bergamote B. is produced by expression from the peels of the nearly ripe fruits of the small ->bergamot tree. Most b. used today is subjected to vacuum distillation to yield the terpeneless oil, free of phototoxic... 

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