Lemon Oil, Expressed

Lemon oil Lemon oil, coldpressed Lemon oil, expressed Lemon peel oil... 

Lemon oil, expressed. See Lemon (Citrus medica limonum) oil... 

Table 45. Comparison of Components of Sicilian and California Expressed Lemon Oils ...

Restrictions for furocoumarin containing essential oils have been recommended for Angelica root oil, Bergamot oil expressed, Bitter orange oil expressed, Cumin oil, Grapefruit oil expressed, Lemon oil cold pressed, Lime oil expressed, Rue oil. 

Lemon Oil, Coldpressed, occurs as a pale to deep yellow or green-yellow liquid with the characteristic odor and taste of the outer part of fresh lemon peel. It is the volatile oil obtained by expression, without the aid of heat, from the fresh peel of the fruit of Citrus limon L. Burmann filius (Fam. Rutaceae) with or without the previous separation of the pulp and the peel. It is miscible with dehydrated alcohol and with glacial acetic acid. It may contain a suitable antioxidant. 

Terpineol, or more strictly, a-terpineol (3.38), is one of the most widespread of monocyclic monoterpenoid alcohols in nature. It is found in flowers such as narcissus and freesia herbs such as sage, marjoram, oregano and rosemary in the leaf oil of Ti-tree Melaleuca alternifolia) and in the oil expressed from the peel of lemons. Reports of the level of terpineol in oils occasionally vary considerably and one wonders how much this is due to variations in the plants and to variations in the isolation process since terpineol could be an artefact. The layman will often describe the odour of terpineol as pine disinfectant since terpineol is, in fact a major component of pine disinfectant. This product is prepared by distillation of turpentine in the presence of acid which results in opening of the ring of a-pinene (3.37) to produce a-terpineol as shown in Figure 3.19. 

Definition Volatile oil expressed from the fresh peel of fruit of Citrus limon, contg. limonene, terpinene, phellandrene, pinene Properties Pale yel. to greenish-yel. liq., lemon peel odor and taste misc. with dehydrated alcohol, CS2, glac. acetic acid si. sol. in water dens. 0.849-0.855 (25/25 C) ref. index 1.4742-1.4755 (20 C)... 

Oil of lemon n. Volatile oil expressed from fresh peel of Citrus limonum. It contains hmonene, terpinene, phellandrene, and pinene. 

Lemon oil, prepared by expressing the peel of the nearly ripe fruit of Citrus limonum, and obtained almost entirely from Sicily and Southern Italy. Specific gravity at 15° C., 0 856-0 860 optical rotation, + 58° to + 63° refractive index at 20° C., 1 4730-1 4750 aldehydes (citral), 2 5 to 4 per cent. 

There are three distinct oils found in commerce, the one, hand-pressed oil obtained from the Citrus Umetta (Italian), the others being the distilled and hand-pressed oils respectively from Citrus medioa var. aoida (West Indian). Expressed oil is prepared from the fruit in December and January. In the south-west of Italy the tree is known as limoncelh di Spagna. The Italian oil somewhat resembles lemon oil, but with a much richer odour, somewhat recalling the odour of bergamot. It contains pinene, limonene, and probably dipentene, linalol, linalyl acetate, and citral. It has the following constants —... 

Lemon oil Citrus limon Fruit rind Expression Limonene, geranial, neral... 

Common/vernacular names Expressed lemon oil, cedro oil (terpeneless). 

Lemon oil is expressed from the 1. fruits, and a - petitgrain oil (petitgrain citronnier) is distilled from its twigs. 

Expressed 1. is a yellowish to dark-green mobile liquid with a fresh, juicy lemon-like and green top-note and a tenacious sweet-lhiity bodynote (- odor description). In - fragrances, expressed 1. is used as a modifier for citrus topnotes, where its richness and perfume-like bodynote in combination with the natural juicy character produce interesting effects. In flavors, expressed 1. is mainly used alongside - lemon oil in soft drinks, ice cream, sherbets and hard candy. 

Exceptions to the simple definition of an essential oil are, for example, gadic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, the physical process of expression, appHed mostly to citms fmits such as orange, lemon, and lime, yields oils that contain from 2—15% nonvolatile material. Some flowers or resinoids obtained by solvent extraction often contain only a small portion of volatile oil, but nevertheless are called essential oils. Several oils are dry-distiUed and also contain a limited amount of volatiles nonetheless they also are labeled essential oils, eg, labdanum oil and balsam oil Pern. The yield of essential oils from plants varies widely. Eor example, nutmegs yield 10—12 wt % of oil, whereas onions yield less than 0.1% after enzymatic development. 

Citraptene, CjiHjoO, is the odourless solid constituent of the expressed oil of lemon. After repeated recrystallisations from acetone and methyl alcohol, it forms needles melting at 146° to 147°. By treatment with bromine in chloroform solution it yields a dibromide, CjoHjdBr O, melting at 250° to 260°. It appears to be a dimethyl-oxycoumarin of the constitution—... 

Cedrat. —The rind of the citron fruit—citrus medico, —yields the oil of cedrat, both by expression and distillation. Its odor is lemon-like. This oil is expensive, and is mixed" only with the finer perfumes. 

By Expression.—This method is adapted only for those substances which are very rich in essential oil as examples, the rinds of the lemon, orange, citron, and some other fruits. The chief implement is a powerful press. The material Is either inclosed in hair bags, or a tinned metal box—Fig, 391— FJs.asi, resting upon the bottom of the press. The box must be lined with a perforated cylinder—Fig, 392—having perpendicular ribs ou the exterior Circumference. These latter, projecting against the inner sides of the box, form Fig.eess. channels by which the flow of... 

BERGAMOT OIL. An essential oil, Brownish-yellow to green liquid, agreeable odor, bitter taste, produced from the nnd of the fruit of Citrus aurantium or C. bergamia, relatives of the orange and lemon, The small trees are cultivated in southern Europe. The oil is expressed from the skin of the small yellow fruits and sometimes is used as a scent for cosmetics. The oil also is used sometimes as a clearing agent in the preparation of material for microscopic examination. 

Exceptions to the simple definition of an essential oil are, for example, garlic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, rhe physical process of expression, applied mostly to citrus fruits such as orange, lemon, and lime, yields oils that contain from 2-15% nonvolatile material. 

SUMMARY In essential oils, most constituents are terpenes and terpenoid molecules. The method of extraction can influence the terpene content. In citrus oils extracted by expression (squeezing or pressing the plant material), the terpenes present are similar to those found in the living plant tissue for example, orange, lemon, mandarin and grapefruit essential oils may be made up of up to 90% of the monoterpene limonene. When extraction is by steam distillation the action of the hot water and steam on thermolabile (heat-sensitive) molecules present in the plant is responsible for the formation of the bulk of the terpene content. Solvent extraction often produces absolutes that are very low in terpenes or do not contain them at all, when compared to a distillation of the same material, for example as found in lavender and rose products. 

Lemon essential oil has the potential to cause skin irritation and sensitization in some individuals. It is recommended that it should be used at a maximum of 1% in a massage blend. When extracted by expression the essential oil is phototoxic so its use should be avoided on the skin prior to exposure to the sun. 

---