D-タガトース

説明D-tagatose is a carbohydrate occurring in small amounts in several foods. The solubility in water is approximately 580 g/L at room temperature. As a ketohexose, tagatose reacts in foods in browning reactions like other ketohexoses, for example, fructose. Tagatose is, depending on the concentration, approximately 92 % as sweet as sucrose and noncariogenic. The caloric value of tagatose is generally set to 1.5 kcal/g. In the European Union, tagatose is approved as a novel food. In the United States, tagatose has GRAS status and it is also approved in many other countries.

使用D-tagatose is a compound useful in organic synthesis.

Tagatose is obtained from D-galactose by isomerization under alkaline conditions in the presence of calcium.

純化方法Crystallise D(-)-tagatose from EtOH/H2O (6:1). It mutarotates from [] 22D +2o (2minutes) to –5.0o (30minutes) (c 4, H2O). The phenylosazone crystallises from aqueous EtOH with m 185-187o(dec), and [] 23D +47o (c 0.82, 2-methoxyethanol). [Totton & Lardy J Am Chem Soc 71 3076 1949, Gorin et al. Canad J Chem 33 1116 1955, Reichestein & Bossard Helv Chem Acta 17 753 1934, Wolfrom & Bennett J Org Chem 30 1284 1965, Beilstein 1 IV 4414.] In D2O at 27o 1H NMR showed the following ratios: -pyranose (79), -pyranose (16), -furanose (1) and -furanose (4) [Angyal Adv Carbohydr Chem 42 15 1984, Angyal & Pickles Aust J Chem 25 1711 1972].