| 摘要 |
PURPOSE:To obtain l-malic acid suitable for medical, food and industrial uses in high yield and in high purity, by bringing a reaction mixture of calcium l-malate into contact with a strongly acidic cation exchange resin. CONSTITUTION:Fumaric acid is successively added to an aqueous solution of calcium hydroxide, potassium hydroxide, etc., and reacted at pH 6-9 to give a reaction solution of calcium l-malate, which is brought into contact with a strongly acidic cation exchange resin (e.g. DIAION SK-1B manufactured by Nippon Rensuisha) to give l-malic acid. The contacting method is carried out by batch method and preferably the solid content is separated from the reaction mixture, water is added to calcium l-malate to form a 20-40W/V%, which is treated for 10min-1hr.
|
