Limes, oil

Terpene-based resins Terpene hydrocarbons Terpeneless lime oil Terp ene-phenolics Terpenes... 

Lime Oil. This oil is obtained from the fmit Citrus aurantijolia Swingle the Key, Mexican, or West Indian lime or C latijolia Tanaka, the Persian lime, either by steam distillation or expression. Either the entire cmshed fmit or only the peel may be used, depending on the specific properties desired. A typical commercial distilled lime oil contains the constituents shown in Table 10 (25). 

Table 10. Components of Typical Commercial Lime Oils ...

Because of its more interesting odor and flavor properties, many perfumers and flavorists prefer to use a terpeneless lime oil. A typical analysis is shown iu Table 10 (26). 

From West Indian lime oil, a trace low Foiling constituent, 1-methyl-1,3-(or 1,5 /74< 5 -3 7- -cyclohexadiene has been characterized (27). This compound, which possesses an intense and characteristic lime aroma, was later confirmed to be the 1,3-isomer [1489-56-1] (11). This compound can easily be made in a biomimetic way through the reaction of citral [5392-40-5] (3,7-dimethyl-2,6-octadienal) with citric acid (28,29). 

L. Mondello, M. Catalfamo, P. Dugo and G. Dugo, Multidimensional capillary GC-GC for the analysis of real complex samples. Part IE Enantiomeric distribution of monoteipene hydrocarbons and monoteipene alcohols of cold-pressed and distilled lime oils , J. Microcolumn Sep. 10 203-212 (1998). 

TTaud-prcaScd esi Indian limes oil is of ooiisid jrahly higlinr value than the distilled oil. Its charactti S are as follows i... 

A specimen from lime oil, however, has been isolated with an optical rotation - 20° 7, and a specimen of dextro-linalol from orange oil, with a rotation of + 19° 18. The characters of pure linalol, therefore, may be taken approximately as follows —... 

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. 

It has been found that the compound 8-geranoxy psoralen is present in citrus oils, particu-lariy lemon and lime oils. This compound can be isolated from the oil by a process which involves primarily absorption on an adsorbent material followed by elution with a suitable solvent. 

A concentrated essential oil. Folding is a gravimctric/volumetric measure of the strength of a concentrated essential oil expressed as a multiple of a standard. A folded Citrus oil would be compared to the expressed oil (steam distilled oil in the case of distilled Lime oil), e.g. 5 x Orange oil. 

Production of Citrus Peel Oils. Apart from distilled lime oil, citrus peel oils are produced by pressing. Pressing of the peels for oil is often combined with juice production [357a]. 

Lime oil may be either pressed or distilled, but the distilled oil is produced on a much larger scale. 

Two varieties of limes are of importance in the commercial production of lime oils the West Indian (Mexican or Key) lime. Citrus aurantifolia (Christm.) Swingle and the Persian (Tahiti) lime, C. latifolia Tanaka. The former has small fruits with many seeds, and the latter bears larger, seedless fruits. West Indian limes are grown primarily in Mexico, the West Indies, and Peru Persian limes are cultivated in Florida and Brazil. 

Persian lime oils contain lower concentrations of the typical sensorially important components than the West Indian lime oils and are thus comparatively mild and flat [395]. Consequently, West Indian lime oils are more popular. 

Pressed lime oils are obtained by rasping and puncturing as described on p. 185, so-called type B. Other methods are also employed for West Indian limes the whole fruits may be chopped and the separated oil-juice emulsion subsequently centrifuged, so-called type A [396], [397],... 

Pressed lime oil is a yellow to greenish-yellow liquid with a strong, characteristic odor, reminiscent of lemon. 

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