Steam distillation essential oils

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

The species Cit us aurantium produces different essential oils depending upon which part of the plant is used. Expression of the outer peel of the almost ripe citrus fruit produces the Bitter orange essential oil, steam distillation of leaves and twigs produces Petitgrain, while steam distillation of the freshly picked flower produces Neroli or orange blossom essential oil. 

EXPERIMENT 9 ANALYSIS OF ESSENTIAL OILS (STEAM DISTILLATES)... 

Qccurance and Identification. An early report of cotton volatile composition by Minyard et al. (44) involved steam distillation of large quantities of leaves and flowers. Major compounds identified included the monoterpenes a-pinene, B-pinene, myrcene, trans-B-ocimene, and limonene ( 4). Several other monoterpene hydrocarbons were also present in low concentration. Since that report, many other terpenes have been identified in cotton essential oil steam distillates and solvent extracts. These compounds include cyclic hydrocarbons such as bisabolene, caryophyllene, copaene and humulene (45-47), the cyclic epoxide caryophyllene oxide (45), cyclic alcohols such as bisabolol, spathulenol, and the aromatic compound... 

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. 

Oil seeds are dried at first to a water content of about 10% to avoid enzymatic hydrolysis. Then they are expelled (pressed) to a fat content of 20%. The ex-peller cake is extracted with hydrocarbons, usually hexane, and is later removed from the oil with water steam. Hexane solubility in water is only 0.1%. Bleaching of the raw oils occurs with aluminum silicates containing montmorillonite at approximately 60°C. Deodorization is the final step in the purification of the fatty raw materials from plants and occurs essentially by steam distillation. 

Deodorization is essentially vacuum steam distillation (190-230 °C, 0.5-10 mbar). The volatile compounds, together with undesirable odorants present in the fat or oil, are separated in this re-... 

Essentia.1 Oils. Essential oils (qv) are extracted from the flower, leaf, bark, fmit peel, or root of a plant to produce flavors such as mint, lemon, orange, clove, cinnamon, and ginger. These volatile oils are removed from plants either via steam distillation, or using the cold press method, which avoids heat degradation. Additional processing is sometimes employed to remove the unwanted elements from the oils, such as the terpenes in citms oils which are vulnerable to oxidation (49,50). 

Absolute Oil. This is the steam distillable portion of an absolute. Frequently, the absolute oil possesses superior odor properties to that of the corresponding essential oil. 

Pommade. These are botanical extracts prepared by the enfleurage method wherein flower petals are placed on a layer of fat which extracts the essential oil. This method is appHed to low odored flowers, which do not yield appreciable oil on steam or water distillation, or flowers of valuable but dehcate odor (such as jasmin), which are destroyed on such treatment. Pommades, as such, are seldom used by the industry at present (ca 1995), but are further processed to provide more concentrated extracts such as absolutes. Absolutes, being alcohol-soluble, are much more convenient forms for the perfumer. 

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. 

Pimento Berry Oil. The pimento or allspice tree, Pimenta dioca L. (syn. P. officinalis, Liadl.), a native of the West Indies and Central America, yields two essential oils of commercial importance pimento berry oil and pimenta leaf oil. The leaf oil finds some use ia perfumery for its resemblance to clove leaf and cinnamon leaf oils as a result of its high content of eugenol. Pimento berry oil is an item of commerce with extensive appHcation by the flavor industry ia food products such as meat sauces, sausages, and pickles, and moderate use ia perfumery, where it is used primarily as a modifier ia the modem spicy types of men s fragrances. The oil is steam-distilled from dried, cmshed, fully grown but unripe fmits. It is a pale yellow Hquid with a warm-spicy, sweet odor with a fresh, clean topnote, a tenacious, sweet-balsamic-spicy body, and a tea-like undertone. A comparative analysis of the headspace volatiles of ripe pimento berries and a commercial oil has been performed and differences are shown ia Table 52 (95). 

Turpentine Oil. The world s largest-volume essential oil, turpentine [8006-64-2] is produced ia many parts of the world. Various species of piaes and balsamiferous woods are used, and several different methods are appHed to obtain the oils. Types of turpentines include dry-distiUed wood turpentine from dry distillation of the chopped woods and roots of pines steam-distilled wood turpentine which is steam-distilled from pine wood or from solvent extracts of the wood and sulfate turpentine, which is a by-product of the production of sulfate ceUulose. From a perfumery standpoint, steam-distilled wood turpentine is the only important turpentine oil. It is rectified to yield pine oil, yellow or white as well as wood spirits of turpentine. Steam-distilled turpentine oil is a water-white mobile Hquid with a refreshing warm-balsamic odor. American turpentine oil contains 25—35% P-pinene (22) and about 50% a-pinene (44). European and East Indian turpentines are rich in a-pinene (44) withHtfle P-pinene (22), and thus are exceUent raw materials... 

Essential Oils. Essential oils are produced by distillation of flowers, leaves, stems, wood, herbs, roots, etc. Distillations can be done directly or with steam. The technique used depends mosdy on the desired constituents of the starting material. Particular care must be taken in such operations so that undesired odors are not introduced as a result of pyrolytic reactions. This is a unique aspect of distillation processing in the flavor and fragrance industry. In some cases, essential oils are obtained by direct expression of certain fmits, particular of the citms family. These materials maybe used as such or as distillation fractions from them (see Oils, essential). 

Orris. Orris is produced from rhi2omes of Ins pallida and Ins germanica. The plants are found and cultivated mosdy ia Italy, but also ia Morocco and China. It is used ia perfumery as an absolute, a steam-distilled essential oil, and a concrete. The last material, which is a low melting soHd (due to a high content of myristic acid) and therefore erroneously called a concrete, is by far the most used. Orris has a violet-like odor useful ia fine perfumes, luxury soaps, and fragrances for powders and other cosmetic products. Its most important odor contributors are the irones, of which the most important isomer... 

Rose. Rose is one of the most important florals ia perfumery, the most valuable derivatives of which are produced from Rosa damascena, which is grown principally ia Bulgaria, but also ia Russia, Turkey, Syria, India, and Morocco. The concrete, absolute, and steam-distilled essential oil (rose otto) are particularly valuable perfume iagredients. Careful handling and processiag of freshly picked flowers are required to produce these materials of warm, deeply floral, and rich odor quaUty. They are complex mixtures of which citroneUol (9), geraniol (8), phenethyl alcohol [60-12-8] (21), and P-damascenone [23726-93 ] (22) (trace component) are important odor constituents. 

The sesquiterpenes found in essential oils have low volatilities compared with monoterpenes and so are isolated mainly by steam distillation or extraction, but some are also isolated by distillation or crystallization. Most of the sesquiterpene alcohols are heavy viscous Hquids and many crystallize when they are of high enough purity. Sesquiterpene alcohols are important in perfume bases for their odor value and their fixative properties as well. They are valuable as carriers of woody, balsamic, or heavy oriental perfume notes. 

Essential Oils. Volatile oils from plants are referred to as essential oils. The oils can be obtained through steam distillation, solvent extraction, or separation of the oils from pressed fmit. They consist of oxygenated compounds, terpenes, and sesquiterpenes. The primary flavor components of essential oils are oxygenated compounds. Terpenes contain some flavors but are often removed from the essential oil because they are easily oxidized (causiag off-flavors or odors) and are iasoluble. Essential oils are prepared from fmits, herbs, roots, and spices. 

Phenyl-2-propenal [104-55-2], also referred to as cinnamaldehyde, is a pale yeUowHquid with a warm, sweet, spicy odor and pungent taste reminiscent of cinnamon. It is found naturally in the essential oils of Chinese cinnamon Cinnamomum cassia, Blume) (75—90%) and Ceylon cinnamon Cinnamomum lanicum, Nees) (60—75%) as the primary component in the steam distilled oils (27). It also occurs in many other essential oils at lower levels. 

The normal boiling point of /V-ethylaniline is 204°C. Therefore, steam distillation makes possible the distillation of /V-ethylaniline at atmospheric pressure at a temperature of 99.15°C instead of its normal boiling point of 204°C. Commercial appHcations of steam distillation include the fractionation of cmde tall oil (qv) (84), the distilling of turpentine (see Terpenoids), and certain essential oils (see Oils, essential). A detailed calculation of steam distiUation of turpentine has been reported (85). 

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