Perfume with product base

Calls for matches that go beyond family resemblance and aim at closeness to a specific model entail technical, practical, and ethical problems. The technical problem lies in the fact that even with the help of GC/MS, far more effort is involved in creating a close rather than an approximate match. The difficulties are multiplied if the character of the perfume is considerably modified by the components of the product base and if, as is usually the case, the cost limits are well below the cost of the original fragrance. 

Another technique much used in the past, though less popular today, was to take well-known products such as methyl ionone, vetiveryl acetate, or hydroxycitronellal—materials that themselves could often form 10-20% of a finished perfume—and decorate them with a number of other synthetic and natural materials to form a base with much of the complexity and "roundness of a finished perfume. Many such bases, for example, Althenol and Selvone (used in Ma Griffe), were created by Carles to be used not only by himself but also by client perfumers who lacked perhaps the same level of technical proficiency. 

Although the perfume oil is usually the first suspect whenever odor or color changes occur in a finished product, it is not always the culprit. Odor and color changes in the product base itself may occur due to oxidation, hydrolytic breakdown, complex formation, bacterial decomposition, or other causes. Sometimes the causes for instability are hard to track down, as in a case in the experience of one of the authors, where an off-odor in a cream was due to microbial breakdown that was made possible by absorption and inactivation of the preservative by the plastic container. It is always advisable to conduct a stability test of the unperfumed product along with the test of the perfumed product. 

Compatibility is, in a sense, the reverse side of stability. While stability is a question of the effects of the medium on the perfume, compatibility has to do with the effects of the perfume upon the medium. Ideally the perfume has no effect whatsoever upon the product base. Special care in perfume formulation may be required to achieve or approach this ideal. In products containing inherently unstable oxidizing agents such as hypochlorites or peroxides, perfume components may accelerate the breakdown of these agents and thus deactivate the product. Dyes used in coloring products may be decolorized or otherwise affected by perfume materials. 

The nature of the product base. Here the relationship is complex. On the one hand, diffusion is far greater from nonpolar solvents such as hydrocarbons and, presumably, fatty acid esters than from pol solvents such as alcohol because the nonpolar solvents cause the plastic to swell, thus increasing its permeability. On the other hand, product bases such as oil-free aqueous systems tend to favor the migration of perfume materials with very low water solubility into the plastic. 

Many product bases that the perfumer has to deal with may be either acidic or alkaline, and as we have already seen, under such conditions a number of materials such as esters, aldehydes, and ketones are likely to be unstable. The severity of the problem depends on the strength and type of acid or alkali concerned. For instance, hydrochloric acid and citric acid are examples of a strong and a weak acid, respectively, and sodium hydroxide and ammonia of a strong and a weak alkali. One way commonly used to express the degree of acidity or alkalinity is by means of the pH value. This is a numerical scale from 1 to 14 in which pH 1 is the most acidic and pH 14 the most alkaline. At pH 7 the product is said to be neutral. 

D-Limonene can be absorbed through the skin after application of citrus oils, perfumes, soaps, and other fragranced personal care products, and through skin contact with citrus-based cleaning products. 

Thus, it is the job of the applications chemist to be the product expert , who should be able to advise and carry out testing on any potential problems or issues related to the perfume in combination with the product base. This advice may be sought by ... 

Phenylethanol has a rose-like odour and makes the chemically produced compound the most used fragrance chemical in perfume and cosmetics, with a world market of about 7,000 t year [107, 108]. 2-Phenylethanol is also found in many foods as a characteristic flavour compound rounding off the overall aroma, especially in foods obtained by fermentation, such as wine, beer, cheese, tea leaves, cocoa, coffee, bread, cider and soy sauce [109]. In food applications, natural 2-phenylethanol is preferred rather than its nature-identical counterpart from chemical synthesis and it has a market volume of 0.5-11 year . This product is sold at market prices of up to US 1,000 per kiklogram and is mainly produced by yeast-based bioprocesses since its isolation from natural sources, e.g. rose oil, would be too costly [109]. 

Floating-Bar Manufacture. Base soap made from the desired blends of fat and oil first is flash-dried to a moisture content of about 22%. It then enters a mechanical mixer called a crutcher, where it is thoroughly mixed with perfume, preservatives, and air. The amount of air controls the density of the final product, giving the bar a density of less than one and making it floatable. 

The floral accords form an essential part of the perfumer s repertoire. They are valuable not only as building blocks, or bases, in the creation of all types of perfume but also as fragrances in their own right. With some modification the floral accords can be used as single floral notes for functional products such as soaps, cosmetics, and household products. They also form an excellent starting point for student perfumers in the formulation of simple compounds. 

It is important when beginning work on a floral base to start with as simple a formula as possible, containing only sufficient materials to establish the essential character of the note. This basic accord can later be embellished by the addition of modifying materials and naturals. The most effective floral bases, particularly when designed to be used as a major part of a perfume formula, are often comparatively simple mixtures containing no more than 15, and often fewer materials. More complicated bases, when used in this way or in combination with other florals, may often be the cause of "muddiness" and general lack of impact in the final product. 

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