Menthol mints

Some flavouring compounds are also perfumes and may also be used as an intermediate in making other compounds. Two such large-scale flavouring compounds are vanillin (vanilla flavour as in ice cream) and menthol (mint flavour) both manufactured on a large scale and with many uses. 

Menthol (mint) Carvone (caraway seeds) Camphor ... 

More than a half of mint oil production falls on peppermint oil and it is the most important because of its exceptional properties. Wide spectrum of therapeutic properties of this oil includes antibacterial and antifungal activities. Biological activity of mint oils is due to the content of their main constituent (IR, 3R, 4S)-(-)-menthol. Mint oils have shown high or middle activity against bacteria and fungi when compared with other essential oils. Peppermint oil was assessed more frequently than Japanese mint oil, that usually was tested as a raw but not dementhohzed oil. 

Artificial materials include aUphatic, aromatic, and terpene compounds that are made synthetically as opposed to those isolated from natural sources. As an example, ben2aldehyde may be made synthetically or obtained from oil of bitter almond (51) and t-menthol may be made synthetically or isolated from oil of Mentha arvensis var. to give Bra2iUan mint oil or com mint oil. 

Flavor. Dentifrices are used to refresh the oral cavity. Flavor oils and other flavoring materials are key to that function (see Flavors and spices). Generally recognized as safe (GRAS) flavors or flavors from approved lists are used. The most popular flavors are peppermint [8006-90-4], spearmint [8008-79-5], cinnamon [8006-79-9], and mixtures of these. Menthol is a principal constituent of the mint flavors and a source of refreshment and coolness. 

Byitropngon wAlis, known as Argeutine mint, icldb about U 4 per cent- of esaential oil. which has been esamined by Dcering. It ia a clear liquid ol specific gravity 0 9lS to 0 920, which on cooling to does not separate any menthol. It boils principally at 210 . The oil contains 2 5 per cent, of furfurol, hut no olhcr consciCucnt has beeu identified. 

The resolution of DL-menthol is important industrially. L-Menthol has a mint taste and gives a cooling sensation. It finds use in a number of important products including toothpaste and confectionary. D-Menthol does not have the same taste nor the same cooling properties. DL-menthol can be produced relatively simply using a variety of chemical routes. 

Pure citronellal is a colorless liquid with a refreshing odor, reminiscent of balm mint. Upon catalytic hydrogenation, citronellal yields dihydrocitronellal, citro-nellol, or dihydrocitronellol, depending on the reaction conditions. Protection of the aldehyde group, followed by addition of water to the double bond in the presence of mineral acids or ion-exchange resins results in formation of 3,7-dimethyl-7-hydroxyoctan-l-al (hydroxydihydrocitronellal). Acid-catalyzed cycli-zation to isopulegol is an important step in the synthesis of (-)-menthol. 

Production. Many industrial processes exist for the production of menthols. For (—)-menthol, isolation from peppermint oil (see Mint Oils) competes with partial and total syntheses. When an optically active compound is used as a starting material, optical activity must be retained throughout the synthesis, which generally consists of several steps. Total syntheses or syntheses starting from optically inactive materials require either resolution of racemic mixtures or asymmetric synthesis of an intermediate. Recently used processes are the following ... 

Cornmint oil, Japanese mint oil is produced by steam distillation of the flowering herb Mentha arvensis var. piperascens Malinv. The crude oil contains ca. 70% (-)-menthol, which can be isolated by crystallization at low temperature. 

Dementholised mint oil Japanese mint oil (-)-Menthol (30-50), menthone (17-35), isomenthone (5-13)... 

Acetylation is of special importance with those essential oils, the value of which depends largely on their content of alcoholic principles such, for instance, are mint (menthol), palmarosa, geranium, rose (geraniol), coriander, linaloe (linalool) and sandalwood (santalol) oils. 

It may seem odd to you to have a chemical process to produce menthol, which would be available naturally from mint plants. This process is now responsible for about half the world s menthol production so it must make some sort of sense The truth is that menthol cultivation is wasteful in good land that could produce food crops such as rice... 

Examples of monoterpenes include the linear aldehyde citral, which is found in many essential oils, and the (cis) alcohol geraniol, a major component of oil of geranium. Cyclic monoterpenes include limonene, menthol, pinene, camphor, and carvone, major components of lemon oil, mint oil, turpentine, camphor oil, and caraway oil, respectively. Sesquiterpenes include farnesol, a component of rose oil, and bisabolene, a component of Bisabol myrrh. The diterpenes include phytol, a component of chlorophyll, and vita-... 

Another important taste sensation is coolness, which is a characteristic of menthol. The cooling effect of menthol is part of the mint flavor complex and is exhibited by only some of the possible isomeric forms. Only (-) and (+) menthol show the cooling effect, the former to a higher degree than the latter, but... 

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