Particulate composition containing anhydrous crystalline 2-O-alpha-D-glucosyl-L-ascorbic acid, process for producing the same, and uses thereof
The present invention aims to provide a particulate composition containing anhydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid having a significantly, hardly solidifiable property compared to conventional ones in a grade for use in quasi-drugs; a process for producing the same; and uses thereof. The present invention solves the above object by providing a particulate composition containing anhydrous crystalline 2-O-α-D-glucosyl-L-ascorbic in an amount of over 98.0% by weight but less than 99.9% by weight, on a dry solid basis; or a degree of crystallinity of 90% or higher for anhydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid; and by providing a process for producing the same and uses thereof.
1. A process for producing a particulate composition comprising anhydrous crystalline 2-O-α-D-glucosyl-L- ascorbic acid;
wherein said particulate composition comprises 2-O-α-D-glucosyl-L- ascorbic acid in an amount of over 98.0% by weight but less than 99.9% by weight, on a dry solid basis; and has a degree of crystallinity of 90% or higher for anhydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid, when calculated based on a profile of powder X-ray diffraction analysis of said particulate composition,
said process comprising the steps of:
(a) allowing cyclomaltodextrin glucanotransferase and glucoamylase in this order to act on a solution comprising amylaceous substance and L-ascorbic acid to obtain a solution comprising 2-O-α-D-glucosyl-L-ascorbic acid in a production yield of 35% by weight or higher of 2-O-α-D-glucosyl-L-ascorbic acid;
(b) purifying the resulting solution to increase the content of 2-O-α-D-glucosyl-L-ascorbic acid to a level of over 86% by weight, on a dry solid basis;
(c) crystallizing anhydrous crystalline 2-O-α-D- glucosyl-L-ascorbic acid from the resulting purified solution;
(d) collecting the resulting precipitated anhydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid without any re-crystallizing step; and
(e) ageing and drying the collected anhydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid; and
said cyclomaltodextrin glucanotransferase is from Geobacillus stearothermophilus Tc-62 or Tc-27, or a mutant cyclomaltodextrin glucanotransferase of Geobacillus stearothermophilus Tc-91, having an amino acid sequence that the 228th lysine residue in the amino acid sequence of SEQ ID NO:1 is replaced with glutamic acid residue.
2. The process of claim 1 , wherein in the step (a), said cyclomaltodextrin glucanotransferase is allowed to act on the solution in combination with a starch-debranching enzyme.
3. The process of claim 1 , wherein, the step (b) contains a step of removing saccharides by column chromatography using an anion-exchange resin, and simulated-moving-bed column chromatography using a cation-exchange resin as a packing material.
4. The process of claim 1 , wherein the step (b) contains a step of removing saccharides by column chromatography using an anion-exchange resin, and column chromatography using a strong-acid cation-exchange resin or a porous resin.
5. The process of claim 1 wherein the dried product of step (e) is pulverized.