The present invention relates to a method for obtaining crystalline L-alanine from an aqueous solution of L-alanine, in particular from an aqueous solution of L-alanine, which is obtained from a fermentation process.

The invention relates to glutamic acid N,N-diacetic acid (GLDA) of the formula GLDA-Y.sub.mH.sub.n, wherein m is less than 0.5, n+m=4, Y is a monovalent cation that is not a proton, in the form of crystals, a process to make these crystals, and their uses, in particular in detergent compositions.

The invention relates to glutamic acid N,N-diacetic acid (GLDA) of the formula GLDA-Y.sub.mH.sub.n, wherein m is less than 0.5, n+m=4, Y is a monovalent cation that is not a proton, in the form of crystals, a process to make these crystals, and their uses, in particular in detergent compositions.

The invention relates to glutamic acid N,N-diacetic acid (GLDA) of the formula GLDA-Y.sub.mH.sub.n, wherein m is less than 0.5, n+m=4, Y is a monovalent cation that is not a proton, in the form of crystals, a process to make these crystals, and their uses, in particular in detergent compositions.

The object of the present invention is to provide a new application of an optical vortex.

For the object, a method for producing crystalline amino acid comprises a step of irradiating a saturated solution of amino acid with optical vortex, and depositing crystalline amino acid in the saturated solution of amino acid.

In the method, it is desirable that the amino acid contains at least one of alanine, arginine, asparagine, asparagine acid, cysteine, glutamine, glutamine acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, and derivative of them.

The object of the present invention is to provide a new application of an optical vortex.

For the object, a method for producing crystalline amino acid comprises a step of irradiating a saturated solution of amino acid with optical vortex, and depositing crystalline amino acid in the saturated solution of amino acid.

In the method, it is desirable that the amino acid contains at least one of alanine, arginine, asparagine, asparagine acid, cysteine, glutamine, glutamine acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, and derivative of them.

The object of the present invention is to provide a new application of an optical vortex.

For the object, a method for producing crystalline amino acid comprises a step of irradiating a saturated solution of amino acid with optical vortex, and depositing crystalline amino acid in the saturated solution of amino acid.

In the method, it is desirable that the amino acid contains at least one of alanine, arginine, asparagine, asparagine acid, cysteine, glutamine, glutamine acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, and derivative of them.

Process for making solid methylglycine diacetate (MGDA) alkali metal salt (a), said process comprising the steps of (A) providing a 35 to 60% by weight aqueous solution of said MGDA salt having a temperature in the range of from 50 to 90° C., (B) adding 0.01 to 2% by weight of a particulate solid with a pore volume in the range of from 0.25 to 0.75 cm.sup.3/g, determined by nitrogen adsorption in accordance with 66134:1998-02 (b), the percentage referring to the content of (a), (C) crystallizing (a), (D) removing said crystalline (a) from the mother liquor.

Process for making solid methylglycine diacetate (MGDA) alkali metal salt (a), said process comprising the steps of (A) providing a 35 to 60% by weight aqueous solution of said MGDA salt having a temperature in the range of from 50 to 90° C., (B) adding 0.01 to 2% by weight of a particulate solid with a pore volume in the range of from 0.25 to 0.75 cm.sup.3/g, determined by nitrogen adsorption in accordance with 66134:1998-02 (b), the percentage referring to the content of (a), (C) crystallizing (a), (D) removing said crystalline (a) from the mother liquor.

Process for making solid methylglycine diacetate (MGDA) alkali metal salt (a), said process comprising the steps of (A) providing a 35 to 60% by weight aqueous solution of said MGDA salt having a temperature in the range of from 50 to 90° C., (B) adding 0.01 to 2% by weight of a particulate solid with a pore volume in the range of from 0.25 to 0.75 cm.sup.3/g, determined by nitrogen adsorption in accordance with 66134:1998-02 (b), the percentage referring to the content of (a), (C) crystallizing (a), (D) removing said crystalline (a) from the mother liquor.