Lemon Oil, Distilled

Lemon Oil, Distilled, occurs as a colorless to pale yellow liquid with the characteristic odor of fresh lemon peel. It is the volatile oil obtained by distillation from the fresh peel or juice of the fruit of Citrus limon L. Burmann filius (Fam. Rutaceae), with or without the previous separation of the juice, pulp, and peel. It is soluble in most fixed oils, in mineral oil, and in alcohol (with haze). It is insoluble in glycerin and in propylene glycol. It may contain a suitable antioxidant. 

Infrared Spectra / Lemon Oil, Distilled, Brazil Type / 749... 

California Lemon Oil Distilled Mexican Lime Oil (same as C) California Lemon Oil (same as G) Spanish Rosemary Oil Terpi neol... 

Citrus grandis seed extract. See Grapefruit (Citrus grandis) seed extract Citrus limon. See Lemon oil, distilled Lemon oil terpeneless Petitgrain, lemon oil Citrus limon extract. See Lemon (Citrus medica limonum) extract... 

Lemon juice powder Lemon juice solids. See Lemon (Citrus medica limonum) juice powder Lemon leaf oil. See Petitgrain, lemon oil Lemon oil Lemon oil, coldpressed. See Lemon (Citrus medica limonum) oil Lemon oil, distilled... 

Lemon oil, distilled Lemon oil terpeneless Lemon (Citrus medica limonum) peel extract Lemon verbena (Lippia citriodora) extract Lemon verbena (Lippia citriodora) oil Licorice (Glycyrrhiza glabra) Licorice (Glycyrrhiza glabra) extract Licorice, (Glycyrrhiza glabra) root extract Lime oil terpeneless Linaloe (Bersera delpechiana) wood oil... 

Pickles aud Karl have made an examination of the essential oil distilled from the fruit of this plant which is alari known as An /mum mcilivm. They find that the oil resides almost entirely in the seeds. By distilling the fruits with steam, aliout 1 per cent, of a pale yellow oil, having an odour cecalliug those of lemon aud eucalyptus, was obtained. The Oil has the following chanteters —... 

This sesquiterpene is a monocyclic compound, first isolated from the essential oil of Bisabol myrrh by Tucholka. It was found in oil of limes, and described by Burgess under the name limene. It occurs in several other essential oils. When separated by fractional distillation from lemon oil, Gildemeister and Mullerfound it to have the following characters —... 

By this process lemon oils are found to contain some 2 5 to 3 per cent, aldehydes, hand-pressed lime oil 8 per cent., citron or cedrat oil 4 per cent., and orange oil 0 75 to 1 per cent, but more recent work has shown that these results are somewhat too low, due probably in part to some of the aldehydes distilling over with the terpenes, and for oils containing only a small percentage of aldehydes, a volumetric method, such as the hydroa lamine process, as modified by A. H. Bennet is much to be preferred, as being both simpler and more rapid to carry out, and also. more accurate. 

Essential oil Steam distillation Spearmint oil, lemon oil, pepper oil... 

Figures 1-4 illustrate the IFT behavior of four citrus oils against water as a function of time at different temperatures. All but one of the lemon oil 2 and orange oil 2 runs were made with triple distilled water. All lemon oil 1 and orange oil 1 runs were made with mono distilled water. Surface tension of the two water samples differed by 0.2 dynes/cm (mean of 6 runs). This difference is not believed to make a major contribution to the IFT aging behavior observed.

For coumarins in orange fruits (115), the HPLC used a Zorbax Rx C8 (250-mm X 4.6-mm ID, 5 fim) column maintained at 25°C, and analysis was performed by binary-gradient elution using 0.1% HOAc in acetonitrile (eluent A) and 0.1% HOAc in HzO (eluent B). In the author s lab, standard coumarins could be separated by isocratic elution on Zorbax Rx C8 column with acetonitrile-0.1% HOAc in water (35 65) at 1.0 ml/min, as presented in previous work (1). The eluate from the column was passed to a UV detector (UV 330 nm) and then into a fluorescence detector (excitation at 340 nm, emission at 425 nm). As for the specificity, some of the coumarins do not have native fluorescence. Nine coumarins are separated under UV 330 nm, and three coumarins could not be detected with fluorescence detection. Detailed conditions for coumarin analysis in foods and absorption spectra of coumarins obtained by online diode array detector with HPLC were presented by Lee and Widmer (1). Since coumarins exhibit strong absorption in the ultraviolet region, absorption at approximately 313 nm has been used to estimate the dilution of cold-pressed lemon oil with distilled oil (12). Analysis of umbelliferone (7-hydroxy-coumarin) and scopoletin (6-methoxy-7-hydroxycoumarin) in citrus fruits was performed using... 

Sale (2 ) investigated the characteristic ultraviolet absorption of lemon oil and concluded that adulteration of lemon oil with distilled lemon oil could be detected. He recommended other chemical and physical criteria of purity also be considered. 

Extractions or extractive distillations with supercritical solvent need to be performed at as high as possible a solubility of oil in the extract or vapor phase in order to reduce the solvent or carrier gas requirement. From our lemon oil-carbon dioxide phase diagrams, it appears that the highest practical solubility level is 0.9 mole % (2.8 wt ) essential oil. This is obtainable at 313 K. At lower temperature, sensitivity of solubility to pressure requires that solubility be lower (e.g., 0.3 mole % at 308 K). 

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). 

Recently, a supercritical carbon dioxide process has been proposed to concentrate certain aromatic constituents in lemon oils, specifically the oxygenated components from limonene (Robey and Sunder, 1984). Although the components can be concentrated by either steam distillation or liquid-liquid extraction, these processes suffer from drawbacks, such as product degradation, low yields, or the requirement of subsequent removal of solvent. The supercritical carbon dioxide process being developed operates at 60°C this precludes degradation of the sensitive essential oils. The extraction and... 

Citrus oils contain up to 95 % monoterpene hydrocarbons (usually (-t)-limonene, but others as well e.g., lemon oil also contains y-terpinene and /l-pinene). The important aroma-determining components of citrus oils are functionalized terpenes and aliphatic compounds (predominantly carbonyl compounds and esters), present only in relatively low concentrations [358, 358a]. Thus, several methods are employed to concentrate citrus oils on an industrial scale. The monoterpene hydrocarbon content is decreased by distillation, liquid-liquid partitioning between two immiscible solvents, or absorption on a carrier such as silica gel. The deterpenized concentrates are marketed under the name Citrus oil a-fold, depending on the concentration factor [358b]. 

Steam distillations are used commonly in many areas of industry and research. The fat in fish meal is determined by passing steam into a suspension of the fish meal. The fat is separated easily and floats to the top of the water in the receiver, where its amount can be determined. This is one of the ways that "oils" are prepared, such as oil of lemon, oil of cinnamon, oil of pine, or oil of peppermint. 

Note A TLC comparison between the different qualities of distilled and squeez.ed lemon oils is given in Figs. 17 and 18. 

---