Nippon Beet Sugar Manufacturing., Co., Ltd.

Nippon Beet Sugar Mfg., Co., Ltd.

Norimitsu Takagi

Tsutomu Aritsuka

Hiroto Kikuchi

Taizo Nagura

Katsuya Honjyo

Fusao Tomita

Kozo Asano

Hiroaki Sakurai

Yoshihiro Senba

A process for producing the crystals of difructose dianhydride III (DFA III), namely a indigestible disaccharide where two fructose molecules are bonded to each other at positions 1, 2' and 2,3&#x2032; (di-D-fructofuranose-1,2&#x2032;:2,3&#x2032;-dianhydride), where solutions containing DFA III are adjusted to and/or maintained at pH 5 or more, preferably pH 5 to 8, and more preferably 6 to 8. DFA III can be produced industrially without lowering the crystal yield even when the crystallization thereof is done in a recycling system; additionally by adjusting the total fructose content in mother solutions for (crude) crystallization to 5% or less per a solid content basis and adjusting the fructose content to 1% or less, DFA III can more effectively be produced.

Process for producing difructose dianhydride III crystals

The invention provides a process for producing the crystals of difructose dianhydride III (DFA III), namely a indigestible disaccharide where two fructose molecules are bonded to each other at positions 1,2' and 2,3&#x2032; (di-D-fructofuranose-1,2&#x2032;,2,3&#x2032;-dianhydride), where solutions containing DFA III are adjusted to and/or maintained at pH 5 or more, preferably pH 5 to 8, and more preferably 6 to 8. In accordance with the invention, DFA III can be produced industrially without lowering the crystal yield even when the crystallization thereof is done in a recycling system; additionally by adjusting the total fructose content in mother solutions for (crude) crystallization to 5% or less per a solid content basis and adjusting the fructose content to 1% or less, DFA III can more effectively be produced.

In the invention, highly pure crystals of difructose dianhydride III (di-D-fructofuranose-1,2':2,3&#x2032;-dianhydride; hereinafter referred to as DFA III) are produced by adding 5% or less of powdered active carbon to a DFA III containing purified solution containing DFA III of 90% or more purity at a concentration of R-Bx 10-60, preferably 40-55, and after stirring, applying the mixture to solid-liquid separation (filtration with diatomaceous, filtration through a membrane filter, ultrafiltration, or continuous centrifugal separation) and concentrating the separated liquid part, followed by immediate crystallization. In the process of the invention, DFA III crystals can be produced efficiently and industrially, and the resulting crystals can be used for various purposes in pharmaceuticals or food and drink since they have no smell. This is characteristics of the invention different from the prior art products.

Process for purifying difructose dianhydride III

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Obihiro, Japan

Norimitsu Takagi