Essential oils from vegetables

They vary widely in composition, but in general may be divided into Liqueurs free from sugar, such as absinthe liqueurs containing sugars and bitter substances, termed bitters, and true liqueurs, which contain sugars and essential oils or vegetable extracts. 

Table 6.4. Composition of essential oils from various vegetative parts of Curcuma tonga L.

SEME is a recent method of extraction, patented in 2004, with the specific objective of obtaining essential oil from plant material [45, 46]. Based on a relatively simple principle, SFME involves placing the vegetable material in a microwave reactor without addition of solvent or water. SFME is a combination of microwave heating and distillation, and is performed at atmospheric pressure. In terms of quality and quantity, SFME seems to be more competitive and economic than classical methods such as hydro or steam distillation [59, 60]. 

Apart from the separation of components of tobacco smoke, atmospherie pollutants, solvents, plant extracts, essential oils, volatile vegetable oils and organic acids etc., for which it is routinely used, gas chromatography is being increasingly used as an analytical tool to study... 

Prostaglandins arise from unsaturated C20 carboxylic acids such as arachidonic acid (see Table 26 1) Mammals cannot biosynthesize arachidonic acid directly They obtain Imoleic acid (Table 26 1) from vegetable oils m their diet and extend the car bon chain of Imoleic acid from 18 to 20 carbons while introducing two more double bonds Lmoleic acid is said to be an essential fatty acid, forming part of the dietary requirement of mammals Animals fed on diets that are deficient m Imoleic acid grow poorly and suffer a number of other disorders some of which are reversed on feed mg them vegetable oils rich m Imoleic acid and other polyunsaturated fatty acids One function of these substances is to provide the raw materials for prostaglandin biosynthesis... 

Materials for flavoring may be divided into several groups. The most common groupings are either natural or artificial flavorings. Natural materials include spices and herbs essential oils and thek extracts, concentrates, and isolates fmit, fmit juices, and fmit essence animal and vegetable materials and thek extracts and aromatic chemicals isolated by physical means from natural products, eg, citral from lemongrass and linalool from hois de rose. 

An absolutely scientific definition of the term essential cr volatile oils is hardly possible, but for all practical purposes they may be defined as odoriferous bodies of an oily nature obtained almost exclusively from vegetable sources, generally liquid (sometimes semi-solid or solid) at ordinary temperatures, and volatile without decomposition. This definition must be accepted within the ordinary limitations which are laid down by the common acceptation of the words, which will make themselves apparent in the sequel, and show that no more restricted definition is either advantageous or possible. Many essential oils, for example, are partially decomposed when distilled by themselves, and some even when steam distilled. 

From the practical point of view, the principal variation of environment which is definitely under the control of the cultivator, is, of course, the alteration in the composition of the soil, which is brought about by scientific manuring, llie analysis of fruits and vegetables will give the ordinary agriculturist much information as to the necessary mineral ingredients to be added to the soil but in the case of essential oils, the conditions are entirely different. The various parts of the plant tissue are affected in different ways by the same mineral salts, and successful development of the fruit or any other given part of the plant may have little or no relationship with the quantity or quality of essential oil produced. So that it is only by actual distillations of the plant, or portion of the plant, coupled with an exhaustive examination of the essential oil, that informative results can be obtained. 

Calkins (1) reported a conservative estimate of 59 million dollars for chemical controls, 38 million dollars for quarantine and fumigation, and 260 million dollars in crop losses. However these figures are small conq>ared to the estimated 15 billion dollars of fruits and vegetables grown per year in California alone. Now that the importance of controlling these fruit flies has been shown, some control methods and efforts to keep these flies from spreading are presented. Some attractants, such as hydrocarbons from kerosene and essential oils, are discussed. 

Examples are the benefits in the area of extraction of vegetable cuticular waxes being separated from the more valuable essential oils, using supercritical CO2 (Stassi and Schiraldi, 1994). A molecular understanding of how a phenomenon like supercritical behavior affects solvent properties is important (Kazarian and Poliakoff, 1995). 

Essential oils occur mainly in aromatic plants. A few of them are found in animal sources, e.g. musk, civet and sperm whale, or are produced by microorganisms [1, 3, 6, 23, 25, 26, 29-33]. The Council of Europe describes essential oil as a product obtained from vegetable raw material [27]. Owing to a ban on animal-based flavour and fragrance materials, essential oils of trade are entirely of plant origin... 

Dietary intake is of great importance. Linoleic acid (C18 2o)6) and a-linolenic acid (C18 3o)3) are the parent essential fatty acids for humans. Both fatty acids derive from vegetable oils. Higher fatty acids are then produced by chain elongation and desaturation. In addition, some of the prime essential fatty acids, AA (C20 4o)6), EPA (C20 5w3) and DHA (C22 6w3), can be obtained directly from the diet. Meat and eggs are rich in AA, whereas fish is a rich source of EPA and DHA [14]. 

Beyond facial creams, facial masks are usually concentrated partide suspensions, and are used to treat and refresh facial skin. The particles are usually either kaoli-nite, Fuller s earth, or illite ( green clay ) or other days. The particles are intended to act as exfoliants and also to adsorb oils from the skin. Other additives span a wide range of materials, including essential oils, vitamins, fruits and vegetables, scents, and pharmaceutical (cosmeceutical) additives, such as salicylic acid when added to treat mild acne. Body clays are like facial masks except that a higher concentration of clay is used in the suspension. 

Linoleic acid is the parent essential fatty acid of the oj-6 series, and as such, must be obtained in the diet.24 It is primarily derived from vegetables and nontropical vegetable oils. When linoleate was... 

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