Odor Absolute

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. 

Oakmoss. Extracts of oakmoss are extensively used in perfumery to furnisli parts of the notes of the fougnre or chypre type. The first step in the preparation of an oakmoss extract is treatment of the Hchen Evemiaprunastri (L.) Ach., collected from oak trees mainly in southern and central Europe, with a hydrocarbon solvent to obtain a concrete. The concrete is then further processed by solvent extraction or distillation to more usable products, of which absolutes are the most versatile for perfumery use. A definitive analysis of oakmoss volatiles was performed in 1975 (52). The principal constituents of a Yugoslav oakmoss are shown in Table 15 (53). A number of phenoHc compounds are responsible for the total odor impression. Of these, methyl P-orcinol carboxylate is the most characteristic of oakmoss. 

The irones (167,168,169), which constitute slightly more than 75% of the volatiles, are primarily responsible for the fine odor of the natural material. For this reason and because of the high cost of orris absolute, synthetic versions of the irones have been commercialized. Of the possible irone stmctures, the y-isomer (168) possesses the best fragrance properties. 

Absolutes. Absolutes are prepared from concretes by further processing to remove materials that can cause solubihty problems in perfumes. This is done by dissolution in alcohol, filtering, and removal of the solvent, usually at reduced pressures. The resulting products are viscous, oily materials which may be diluted with low odor substances such as diethyl phthalate. 

Concretes and absolutes, both obtained by total extraction of the plant material and not subject to any form of distillation other than solvent removal, are complex mixtures containing many chemical types over wide molecular weight ranges. In some cases, gas chromatographic analysis shows httle volatile material. Yet these products have powerful odors and contribute in important ways to the perfumes in which they are used. 

Jasmine. Jasmine is one of the most precious florals used ia perfumery. The concrete of jasmine is produced by hydrocarbon extraction of flowers from Jasminum officinale (var. GrandijJorum). The concrete is then converted to absolute by alcohoHc extraction. It is produced ia many countries, the most important of which is India, followed by Egypt. Jasmine products are rather expensive and are produced ia relatively small amounts compared with other materials. However, jasmine is particularly important ia perfume creation for its great power and aesthetic quaUties. Eour of the principal odor contributors to jasmine are OT-jasmone [488-10-8] (14), methyl jasmonate [91905-974-] (15), benzyl acetate [140-11 ], and iudole [120-72-9] (16). 

L v ndin. Lavandin, Lavandula hjbrida as a plant species is of recent origin, unknown until the late 1920s. It is a hybrid of two common lavenders, l vandula officinalis and l vandula latifolia. Lavandin is cultivated mainly ia southern France and has become one of the most produced and used natural perfumery materials. The flowering tops of the shmb are used to produce a concrete, an absolute, and a steam-distilled oil the last is by far the most used. Low cost and refreshing odor quaUty allow lavandin to be employed ia a wide variety of perfume appHcations and at high concentrations. Chemically it is comprised of 30—32% linalool (3) and linalyl acetate (1), along with numerous other substances, mosdy terpenic. 

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... 

Orange Flower. Extraction of freshly picked flowers of the bitter orange tree, dims aurantium (subspecies amard) for the production of concrete is carried out mainly ia Morocco and Tunisia. Most of this material is processed further to give orange flower absolute, one of the most important absolutes used ia perfumes after rose and jasmine. It is highly valued ia perfumery, even when used at low levels, for its long-lasting, rich, warm, yet dehcate and fresh floralcy. The material is a complex mixture, to which methyl anthranilate [134-20-3] linalool (3), methyl jasmonate (15), and iadole (16) are important odor contributors. 

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. 

Violet Leaf. Violet leaf absolute is produced by the usual extraction methods from Viola odorata (var. Victoria). It is grown mainly ia the south of France and Egypt. Although this material is not produced ia large amounts, it is quite valuable ia perfumery for its powerhil green leafy and doral character, an odor that belongs to many doral bouquets. The principal odorant ia violet leaf absolute is 2-/n j -6-i7j -nonadienal [55748-2]. 

The quaHty, ie, level of impurities, of the fats and oils used in the manufacture of soap is important in the production of commercial products. Fats and oils are isolated from various animal and vegetable sources and contain different intrinsic impurities. These impurities may include hydrolysis products of the triglyceride, eg, fatty acid and mono/diglycerides proteinaceous materials and particulate dirt, eg, bone meal and various vitamins, pigments, phosphatides, and sterols, ie, cholesterol and tocopherol as weU as less descript odor and color bodies. These impurities affect the physical properties such as odor and color of the fats and oils and can cause additional degradation of the fats and oils upon storage. For commercial soaps, it is desirable to keep these impurities at the absolute minimum for both storage stabiHty and finished product quaHty considerations. 

Phenyl-2-propen-l-ol [104-54-1], commonly referred to as cinnamyl alcohol, is a colorless crystalline soHd with a sweet balsamic odor that is reminiscent of hyacinth. Its occurrence in nature is widespread as, for example, in Hyacinth absolute (Hyacinthus orientalis) (42), the leaf and bark oils of cinnamon Cinnamomum cassia, Cinnamomum lancium, etc), and Guava fmit [Psidiumguajava L.) (43). In many cases it is also encountered as the ester or in a bound form as the glucoside. 

Four characteristics of odor are subject to measurement by sensory techniques intensity, detectability, character (quality), and hedonic tone (pleasantness-unpleasantness) (16). Odor intensity is the magnitude of the perceived sensation and is classified by a descriptive scale, e.g., faint-moderate-strong, or a 1-10 numerical scale. The detectability of an odor or threshold limit is not an absolute level but depends on how the odorant is present, e.g., alone or in a mixture. Odor character or qualit) is the characteristic which permits its description or classification by comparison to other odors, i.e., sweet or sour, or like that of a skunk. The last characteristic is the hedonic type, which refers to the acceptability of an odorant. For the infrequent visitor, the smell of a large commercial bread bakery may be of high intensity but pleasant. For the nearby resident, the smell may be less acceptable. 

Odor control by the addition of dilution air involves a problem associated with the breakdown of the dilution system. If a dilution fan, motor, or control system fails, the odorous material will be released to the atmosphere. If the odor is objectionable, complaints will be noted immediately. Good operation and maintenance of the dilution system becomes an absolute requirement, and redundant systems should be considered. 

Removal of particulates, colloidal matter, iron and organics. Multimedia, manganese, greensand, diatomaceous earth, brim, or carbon filter. Caution carbon filters not recommended unless absolutely required for the removal of color and odor (as they provide a medium for microbial growth). 

Nuisance levels for odors are not absolute, but are related to the minimum detectable level for 50 per cent of the population. These levels have been explored by Warren Spring Laboratories, who have concluded that five times the minimum detectable level is likely to give rise to complaint. 

When stored in a dry, tightly stoppered container the reagent can be kept for long periods without deteriorating (odor), but samples withdrawn after some time are best recrystallized from absolute alcohol before use. 

Odor measurements must be carried out with the help of a team leader, who instructs the panelists and operates the measuring equipment. Communication between the team leader and the panel has to be kept to an absolute minimum. Because of fatigue, the duration of a test series as well as the time of the whole session should be limited. Breaks of at least the same duration as the proceeding test period should be provided. 

By the Method of Frequency the stimulus range is selected in discrete intervals so that the frequency of positive answers is distributed over the range between 1% and 99%. In general, the frequency of positive responses either for an individual or for a group, is cumulatively normally distributed over a geometric intensity continuum. The absolute odor threshold can then be defined as the effective dose corresponding to an arbitrarily selected frequency of positive responses, ordinarily 50% ED50 Effective dose at the 50% level. 

However, there may be a type of poisoning that does not arise from high levels of histamine, therefore a low histamine level may not be an absolute assurance of product safety. It may be more appropriate to state that the absence of decomposition in the fish renders it a safe product. As such, a safe product would have no evidence of spoilage, including odors of decomposition, high histamine levels, or other amines, e.g. cadaverine. 

Properties and handling. Ethyl alcohol is a colorless, flammable liquid (good for flam be ) having a characteristic odor nearly universally recognizable. It is soluble in water (and club soda) in all proportions. Its commercially available as 190 proof (the 95% ethyl alcohol-water azeotrope) and absolute (200 proof). It is frequently denatured to avoid the high tax associated with 190 and 200 proof grades. Methanol and/or sometimes formaldehyde are common denaturants used to prevent consumption as an alcoholic beverage. 

Properties and handling. IPA is/a colorless, flammable liquid with that characteristic, rubbing alcohol odor. Ifs soluble in water in all proportions, as well as most organic solvents. It is commercially available in technical grade (91%), chemical (98%), and absolute (99 %). Shipments by rail, truck, drum, etc., are routine, except that the flammability requires hazardous materials warnings. 

Hyperbaric pressure may intensify odors or render odoriferous some odorless gases such as methane. Professional divers, experimentally exposed to hyperbaric pressures, detected odors of krypton and methane when sniffing these during the decompression phase of a dive. The threshold for krypton was 2 ATA (atmosphere absolute), and 100% positive responses occurred at 6 ATA. For methane, the threshold was 3 ATA (100% 13 ATA). The thresholds of individuals differed by as much as a factor of three (Laffort and Gortan, 1987). 

Interesting examples of single stereoisomers of natural and synthetic odorants, prepared via bioorganic routes, support the statement that our sense of smell is enantioselective. Nowadays, we have enough good quality data to know that sometimes absolute configuration affects odor perception. 

White or light-yellow crystalline solid (or amorphous sohd depending on the method of production) odor of HCl hygroscopic melts at 190°C at 2.5 atm sublimes at 181.2°C density 2.44 g/cm at 25°C decomposes in water evolving heat soluble in HCl soluble in many organic solvents, including absolute ethanol, chloroform, carbon tetrachloride and ether slightly soluble in benzene. 

Chloropicrin (PS)—trichloronitromethane, CCl3N02 Green Cross, Klop—Is a colorless, volatile, slightly oily liquid with an Intense odor (see Table 4-1). It is very slightly soluble in water, soluble in ether, and miscible with benzene, absolute alcohol, and carbon disulfide.10It boils at about 112°C. 

R = CH2C6Hs, C14H12O2, Mr 212.25, 6p2.okPa 170-171 °C, df 1.1121, ng 1.5680, is the main component of Peru balsam oil. It occurs in fairly large amounts in a number of blossom concretes and absolutes (e.g., tuberose and hyacinth). It forms either a viscous liquid or solid flakes mp 21 22°C) and has a weak, sweet-balsamic odor. It is prepared either by transesterification of technical methyl benzoate with benzyl alcohol, or from benzyl chloride and sodium benzoate. A third process starts with benzaldehyde which is converted in high yield into benzyl benzoate in the presence of sodium or aluminum benzylate (Tishchenko reaction). 

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