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A sugar alcohol is an organic compound and a class of polyols, also called polyhydric alcohol, polyalcohol, alditol or glycitol. Contrary to its name, it is neither a alcoholic beverage nor sugar. They are white, water-soluble solids that occur naturally and are used widely in the food industry as thickeners and sweeteners. In commercial foodstuffs, sugar alcohols are commonly used in place of table sugar (sucrose), often in combination with high intensity artificial sweeteners to counter the low sweetness. Unlike sugars, sugar alcohols do not contribute to the formation of tooth cavities. ==Production and structure== Sugar alcohols have the general formula HOCH2(CHOH)nCH2OH. In contrast, sugars have two fewer hydrogen atoms, for example HOCH2(CHOH)nCHO or HOCH2(CHOH)n−1C(O)CH2OH. The sugar alcohols differ in chain length. Most have five- or six-carbon chains, because they are derived from pentoses (five-carbon sugars) and hexoses (six-carbon sugars), respectively. They have one OH group attached to each carbon. They are further differentiated by the relative orientation (stereochemistry) of these OH groups. Unlike sugars, which tend to exist as rings, sugar alcohols do not. They can however be dehydrated to give cyclic ethers, e.g. sorbitol can be dehydrated to isosorbide. Sugar alcohols occur naturally and at one time, mannitol was obtained from natural sources. Today, they are often obtained by hydrogenation of sugars, using Raney nickel catalysts.〔Hubert Schiweck, Albert Bär, Roland Vogel, Eugen Schwarz, Markwart Kunz, Cécile Dusautois, Alexandre Clement, Caterine Lefranc, Bernd Lüssem, Matthias Moser, Siegfried Peters "Sugar Alcohols" Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim. 〕 The conversion of glucose and mannose to sorbitol and mannitol is given: :HOCH2CH(OH)CH(OH)CH(OH)CH(OH)CHO + H2 → HOCH2CH(OH)CH(OH)CH(OH)CH(OH)CHHOH More than a million tons of sorbitol are produced in this way annually. Xylitol and lacticol are obtained similarly. Erythritol on the other hand is obtained by fermentation of glucose and sucrose. 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「Sugar alcohol」の詳細全文を読む スポンサード リンク
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