D,/-Limonene

Two experiments are described in this paper. In the first experiment students determine the %w/w orange oil in a prepared sample by analyzing for d-limonene using anisole as an internal standard. Separations are accomplished using... 

Humidity does not affect the permeabihty, diffusion coefficient, or solubihty coefficient of flavor/aroma compounds in vinyhdene chloride copolymer films. Studies based on /n j -2-hexenal and D-limonene from 0 to 100% rh showed no difference in these transport properties (97,98). The permeabihties and diffusion coefficients of /n j -2-hexenal in two barrier polymers are compared in Table 12. Humidity does not affect the vinyhdene chloride copolymer. In contrast, transport in an EVOH film is strongly plasticized by humidity. 

D-limonene (Florida Chemicals). A compound of optically active terpene (CioHie) derived as an extract from orange and lemon oils limited data shows veiy low viscosity at low temperatures—only one centipoise at —50°C natural substance having questionable stabihty, Theiminol D-12 (Mon.santo). A synthetic hydrocarbon clear liquid ... 

Crude turpentine is distilled to obtain refined products used in the fragrance and flavour industry. Only the unsaturated mono- and bicyclic terpenes are of interest for resin production. These are mainly a-pinene, p-pinene and dipentcne (D,L-limonene) (Fig. 17). D-Limonene is obtained by extraction of orange peel in citrus fruits. 

The constituents identified were d-limonene, l-piucne. dactydeue, and the methyl cthi-r ol eugenol. 

The Oil coutainS d-c-pinene, d-limonene, Intcea o[ palmitic acid, salicylic aHd, aud a pberiol, small quaotitles of esters of formic and valerianic acids, and a sesqnUerpene of specific gravitv 0 910, and retractive index 1-oOSO. 

Dipentene is the racemic form of the optically active d-limonene and 1-limonene, terpenes which are found to a very large extent in essential oils. Since an equal mixture of d-iimonene and f-limonene is dipentene, it is obvious that whenever optically active limonene is found with a rotation below the maximum, it must contain dipentene. Mixtures of equal quantities of a compound of the optically active limonenes are identical with the corresponding compound prepared from dipentene. It is therefore obvious that the nomenclature is unfortunate and dipentene should be termed i-limonene. 

D-Limonenediozonide Polymer (Diozonid des d-Limonens in Ger). (C j 0Hl 6 06 )x, white, solid, mp 60—65°, explds on heating to about 85°. Sol in w, ale, eth, benz v sol in chlf, ethyl acetate and AcOH. Prepd by ozonization of d-limonene, C10H16, dissolved in chlf or CC14 Note Llmonenediozonide was first described by H. Neresheimer, Dissertation, Kiel (1907)... 

Grosjean D, EL Williams, E Grosjean, JM Andino, JH Seinfeld (1993c) Atmospheric oxidation of biogenic hydrocarbons reaction of ozone with 3-pinene, D-limonene, and rra -caryophyllene. Environ Sci Technol 27 2754-2758. 

Massaldi, H.A., King, C.J. (1973) Simple technique to determine solubilities of sparingly soluble organics solubility and activity coefficients of d-limonene, butylbenzene, and n-hexyl acetate in water and sucrose solutions../. Chem. Eng. Data 18,393-397. McAuliffe, C. (1963) Solubility in water of Q - C9 hydrocarbons. Nature (London) 200, 1092-1093. 

Wattenberg LW and Coccia JB. 1991. Inhibition of 4-(methylnitrosamino)-l-(3-pyridyl)butanone carcinogenesis in mice by D-limonene and citrus fruit oil. Carcinogenesis 12 115-117. 

Consider using naturally extracted solvents like pine oil and d-limonene for environmentally friendly products. 

The double-bond isomerization of cyclic materials possessing two double bonds takes place readily. When 1,4-cyclooctadiene is contacted with high-surface sodium on alumina at 0° for a short time, over 95% of the 1,3-cyclooctadiene results (IIS). However an even more interesting reaction takes place when the cyclic diolefin possesses a six-membered ring. An example is the reaction (D) of d-limonene which yields p-cymene and hydrogen (6). 

Kanerva RE, Ridder GM, Lefever FR, et al. 1987. Comparison of short-term renal effects due to oral administration of decalin or d-limonene in young adult male Fisher-344 rats. Food Chem Toxicol 25 345-353. 

Some secondary plant compounds have proven carcinogenic in laboratory rodents. These include D-limonene in orange juice 5-8-methoxypsoralen in parsley and parsnips and caffeic acid in coffee, but also in smaller amounts in apples, apricots, broccoli, Brussels sprouts, cabbage, cherries, kale, peaches, pears, and plums (Ames and Gold, 1990 Ames etal., 1990). How dangerous these compounds can be to human health, is still being debated. 

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