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JP-2026075517-A - Method for producing a powder containing chitin or partially deacetylated chitin nanofibers, and a powder containing chitin or partially deacetylated chitin nanofibers

JP2026075517AJP 2026075517 AJP2026075517 AJP 2026075517AJP-2026075517-A

Abstract

[Problem] To provide a powder containing chitin or partially deacetylated chitin nanofibers that has excellent preservation and handling properties and can be redispersed in water. [Solution] An aqueous solution or aqueous dispersion of dextrin is mixed with a nanofiber dispersion of chitin or partially deacetylated chitin, and the resulting mixture is dried to obtain a powder containing nanofibers of chitin or partially deacetylated chitin. [Selection Diagram] None

Inventors

  • 清瀬 正敏
  • 足立 征也
  • 中川 麻里
  • 正司 禎朗

Assignees

  • 甲陽ケミカル株式会社
  • ＣＨＥＭＩＰＡＺ株式会社
  • 株式会社マリンナノファイバー

Dates

Publication Date
20260508
Application Date
20241022

Claims (11)

  1. A method for producing a powder containing chitin or partially deacetylated chitin nanofibers, comprising the steps of: mixing an aqueous solution or aqueous dispersion of dextrin with an aqueous dispersion of chitin or partially deacetylated chitin nanofibers; and drying the mixture obtained in the first step.
  2. The method for producing a powder containing 1.2% to 87.5% by weight of chitin or partially deacetylated chitin nanofibers, as described in claim 1.
  3. The manufacturing method according to claim 1 or 2, wherein the dextrin is a dextrin or maltodextrin having a dextrose equivalent (DE) of 2 to 20 and an average molecular weight of 1,000 to 11,000.
  4. The manufacturing method according to claim 1 or 2, wherein the dextrin concentration of the aqueous solution or aqueous dispersion of dextrin is 2% to 30% by weight.
  5. The manufacturing method according to claim 1 or 2, wherein the aqueous dispersion of chitin or partially deacetylated chitin nanofibers is 0.1% to 30% by weight of chitin or partially deacetylated chitin nanofibers.
  6. The manufacturing method according to claim 1 or 2, wherein the mixing ratio of dextrin to chitin or partially deacetylated chitin nanofibers (dextrin: chitin or partially deacetylated chitin nanofibers) is 85:1 to 1:7 by weight.
  7. A manufacturing method according to claim 1 or 2, wherein the median diameter of an aqueous dispersion of a powder containing nanofibers of chitin or partially deacetylated chitin, as measured at 25°C by laser diffraction/scattering particle size distribution analysis, is 20 μm to 80 μm.
  8. A powder containing chitin or partially deacetylated chitin nanofibers and dextrin.
  9. The powder according to claim 8, containing 1.2% to 87.5% by weight of chitin or partially deacetylated chitin nanofibers.
  10. The powder according to claim 8 or 9, wherein the dextrin is dextrin or maltodextrin having a dextrose equivalent (DE) of 2 to 20 and an average molecular weight of 1,000 to 11,000.
  11. The powder according to claim 8 or 9, wherein the median diameter of the aqueous dispersion, measured at 25°C by laser diffraction/scattering particle size distribution analysis, is 20 μm to 80 μm.

Description

This invention relates to a method for producing a powder containing chitin or partially deacetylated chitin nanofibers, and to a powder containing chitin or partially deacetylated chitin nanofibers produced by the said method. Chitin nanofibers are chitin (poly-β1-4-N-acetylglucosamine) fibers with a fiber diameter of approximately 2 nm to 200 nm. They have been reported to have effects such as wound healing, suppression of intestinal inflammation, promotion of fibroblast growth factor production in the skin, improvement of bread-making properties, and induction of disease resistance in plants (Non-Patent Literature 1), and their application is being considered in various fields such as medical materials, cosmetics, and food. Chitin nanofibers are produced by extracting and purifying chitin from the shells of crustaceans such as shrimp and crabs, and then defibrating it by wet grinding or the like (Patent Document 1). However, they are usually provided in the form of a dispersion in water. Chitin nanofibers, when dried, form strong aggregates through hydrogen bonding and do not return to a clean dispersion state even when dispersed in water again. Therefore, their storage and distribution must be carried out in an environment that does not allow them to dry out, i.e., while dispersed in a solvent such as water, which has resulted in various limitations in handling and application to various materials. Furthermore, while partially deacetylated chitin nanofibers, like chitin nanofibers, are being considered for applications in various fields, they also face the same problems as chitin nanofibers. Therefore, there is a strong demand for powdered chitin or partially deacetylated chitin nanofibers that offer excellent preservation and handling properties, are redispersible in water, and have fewer restrictions and greater convenience in distribution and various applications. International Publication No. 2010/073758 Chemistry and Biology 53(7) 473-477 (2015) Figure 1 shows the change in viscosity when a shear force is applied to the aqueous dispersions of each powder prepared in Examples 1 to 4, as well as the aqueous dispersion of partially deacetylated chitin nanofibers used as raw materials, in Test Example 5. The present invention provides a method for producing a powder containing nanofibers of chitin or partially deacetylated chitin (hereinafter also referred to as "the method of the present invention" in this specification). The method of the present invention comprises the steps of mixing an aqueous solution or aqueous dispersion of dextrin with an aqueous dispersion of chitin or partially deacetylated chitin nanofibers, and drying the mixture obtained in the first step. The dextrin used in the method of the present invention is obtained by hydrolyzing starch or glycogen with acid or enzyme to reduce its molecular weight, and includes dextrin with a dextrose equivalent (DE) of 10 or less, and maltodextrin with a dextrose equivalent (DE) of about 10 to 20. In the present invention, dextrin or maltodextrin with a dextrose equivalent (DE) of 2 to 20 and an average molecular weight of 1,000 to 11,000 is preferably used, and dextrin or maltodextrin with a dextrose equivalent (DE) of 4 to 11 and an average molecular weight of 1,900 to 6,000 is more preferably used. The above-mentioned dextrin is preferably used as an aqueous solution or aqueous dispersion in an amount of 2% to 30% by weight, more preferably 2% to 20% by weight. The chitin nanofibers used in the method of the present invention are ultrafine fibers made by micronizing chitin (poly-β1-4-N-acetylglucosamine) to a fiber diameter of typically 2 nm to 200 nm, preferably 2 nm to 40 nm, and more preferably 2 nm to 20 nm, and can be manufactured by known methods. For example, they can be obtained by the method described in Patent Document 1, that is, by purifying a material derived from a chitin-containing organism such as crustaceans, insects, or krill by subjecting it to at least one deproteinization step (such as alkali treatment) and at least one demineralization step (such as acid treatment), and then subjecting it to a defibration treatment (such as grinding with a millstone grinder, high-pressure homogenizer treatment, or freeze-drying treatment). Furthermore, naturally occurring chitin contains not only N-acetylglucosamine but also glucosamine as a constituent component, and its degree of deacetylation is approximately 10%. In addition, when preparing chitin nanofibers from biological materials containing chitin as described above, deproteinization treatment may result in the elimination of some acetyl groups. Therefore, the chitin nanofibers used in the method of the present invention may include chitin nanofibers in which part of the chitin structure has been deacetylated. Furthermore, in the method of the present invention, as chitin nanofibers, it is possible to use chitin nanofibers that have been obtained by washing and removing deacetyla