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|Section2= |Section3= |Section4= |Section5= |Section6= }} Vanillin is a phenolic aldehyde, which is an organic compound with the molecular formula C8H8O3. Its functional groups include aldehyde, hydroxyl, and ether. It is the primary component of the extract of the vanilla bean. Synthetic vanillin is now used more often than natural vanilla extract as a flavoring agent in foods, beverages, and pharmaceuticals. Vanillin and ethylvanillin are used by the food industry; ethylvanillin is more expensive, but has a stronger note. It differs from vanillin by having an ethoxy group (–O–CH2CH3) instead of a methoxy group (–O–CH3). Natural "vanilla extract" is a mixture of several hundred different compounds in addition to vanillin. Artificial vanilla flavoring is often a solution of pure vanillin, usually of synthetic origin. Because of the scarcity and expense of natural vanilla extract, synthetic preparation of its predominant component has long been of interest. The first commercial synthesis of vanillin began with the more readily available natural compound eugenol. Today, artificial vanillin is made either from guaiacol or lignin. Lignin-based artificial vanilla flavoring is alleged to have a richer flavor profile than oil-based flavoring; the difference is due to the presence of acetovanillone, a minor component in the lignin-derived product that is not found in vanillin synthesized from guaiacol.〔According to Esposito 1997, blind taste-testing panels cannot distinguish between the flavors of synthetic vanillin from lignin and those from guaicol, but can distinguish the odors of these two types of synthetic vanilla extracts. Guaiacol vanillin, adulterated with acetovanillone, has an odor indistinguishable from lignin vanillin.〕 == History == Vanilla was cultivated as a flavoring by pre-Columbian Mesoamerican people; at the time of their conquest by Hernán Cortés, the Aztecs used it as a flavoring for chocolate. Europeans became aware of both chocolate and vanilla around 1520.〔Esposito 1997〕 Vanillin was first isolated as a relatively pure substance in 1858 by Nicolas-Theodore Gobley, who obtained it by evaporating a vanilla extract to dryness, and recrystallizing the resulting solids from hot water.〔Gobley 1858〕 In 1874, the German scientists Ferdinand Tiemann and Wilhelm Haarmann deduced its chemical structure, at the same time finding a synthesis for vanillin from coniferin, a glucoside of isoeugenol found in pine bark.〔Tiemann 1874〕 Tiemann and Haarmann founded a company, Haarmann and Reimer (now part of Symrise) and started the first industrial production of vanillin using their process in Holzminden, Germany. In 1876, Karl Reimer synthesized vanillin (2) from guaiacol (1).〔Reimer 1876〕 By the late 19th century, semisynthetic vanillin derived from the eugenol found in clove oil was commercially available.〔According to Hocking 1997, synthetic vanillin was sold commercially in 1874, the same year Tiemann and Haarmann's original synthesis was published. Haarmann and Reimer, one of the corporate ancestors of the modern flavor and aroma manufacturer Symrise, was in fact established in 1874. However, Esposito 1997 claims that synthetic vanillin first became available in 1894 when Rhône-Poulenc (since 1998, Rhodia) entered the vanillin business. If the former claim is correct, the authors of the latter article, being employees of Rhône-Poulenc, may have been unaware of any previous vanillin manufacture.〕 Synthetic vanillin became significantly more available in the 1930s, when production from clove oil was supplanted by production from the lignin-containing waste produced by the sulfite pulping process for preparing wood pulp for the paper industry. By 1981, a single pulp and paper mill in Ontario supplied 60% of the world market for synthetic vanillin.〔Hocking 1997〕 However, subsequent developments in the wood pulp industry have made its lignin wastes less attractive as a raw material for vanillin synthesis. While some vanillin is still made from lignin wastes, most synthetic vanillin is today synthesized in a two-step process from the petrochemical precursors guaiacol and glyoxylic acid.〔 Beginning in 2000, Rhodia began marketing biosynthetic vanillin prepared by the action of microorganisms on ferulic acid extracted from rice bran. At $700/kg, this product, sold under the trademarked name Rhovanil Natural, is not cost-competitive with petrochemical vanillin, which sells for around $15/kg.〔Rouhi 2003〕 However, unlike vanillin synthesized from lignin or guaiacol, it can be labeled as a natural flavoring. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Vanillin」の詳細全文を読む スポンサード リンク
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