Chitin and process for producing chitin and/or chitosan by the enzymatic and chemical pathway
The present invention relates to chitin with a differential purity of more than 97.75% and to a process for producing chitin and/or chitosan by the enzymatic and chemical pathway.
1. A method for obtaining chitin and/or chitosan, from insects, comprising the following steps in the following order:
(i) separating cuticles from a soft part of each insect,
(ii) enzymatically hydrolyzing the cuticles with a protease to obtain a solid residue,
(iii) treating the solid residue obtained at step (ii) with a base for a duration between 5 and 60 hours with an aqueous basic solution, wherein the molar concentration of the base in aqueous solution is between 0.1 and 5 mol·L −1 ;
(iv) recovering chitin from step (iii); and, optionally,
(v) deacetylating chitin and recovering chitosan,
wherein the insects are coleopterans and/or lepidopterans, and
wherein the protease is selected from the group consisting of aminopeptidases, metallocarboxypeptidases, serine endopeptidases, cysteine endopeptidases, aspartic endopeptidases, and metalloendopeptidases.
2. The method of claim 1 , wherein separating of the cuticles from the soft part of each insect is performed using a belt separator.
3. The method of claim 1 , wherein the protease is a serine endopeptidase.
4. The method of claim 1 , wherein the treatment with the base is carried out with a strong base.
5. A method for obtaining chitin, from insects, comprising the following steps in the following order:
(i) killing of the insects,
(ii) separating cuticles from a soft part of each insect,
(iii) enzymatically hydrolyzing the cuticles with a protease to obtain a solid residue,
(iv) treating the solid residue obtained at step (iii) with a base for a duration between 5 and 60 hours with an aqueous basic solution, wherein the molar concentration of the base in aqueous solution is between 0.1 and 5 mol·L −1 , and
(v) recovering the chitin from step (iv),
wherein the insects are coleopterans and/or lepidopterans, and
wherein the protease is selected from the group consisting of aminopeptidases, metallocarboxypeptidases, serine endopeptidases, cysteine endopeptidases, aspartic endopeptidases, and metalloendopeptidases.
6. A method for obtaining chitosan, from insects, comprising the following steps in the following order:
(i) killing of the insects,
(ii) separating cuticles from a soft part of each insect,
(iii) enzymatically hydrolyzing the cuticles with a protease to obtain a solid residue,
(iv) treating the solid residue obtained at step (iii) with a base for a duration between 5 and 60 hours with an aqueous basic solution, wherein the molar concentration of the base in aqueous solution is between 0.1 and 5 mol·L −1 ,
(v) recovering the chitin from step (iv),
(vi) deacetylating the chitin, and
(vii) recovering the chitosan,
wherein the insects are coleopterans and/or lepidopterans, and
wherein the protease is selected from the group consisting of aminopeptidases, metallocarboxypeptidases, serine endopeptidases, cysteine endopeptidases, aspartic endopeptidases, and metalloendopeptidases.