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JP-7854793-B2 - Methods for isomerizing trans xanthophylls

JP7854793B2JP 7854793 B2JP7854793 B2JP 7854793B2JP-7854793-B2

Inventors

  • 大澤 友紀子
  • 平澤 和明
  • 川嶋 祐貴
  • 本田 真己

Assignees

  • 株式会社ＥＮＥＯＳマテリアル

Dates

Publication Date
20260507
Application Date
20211118

Claims (13)

  1. A method comprising a contact step of contacting a microorganism containing trans xanthophyll with a fluid containing supercritical CO2 and an organic solvent having a solubility of astaxanthin of 0.001 g/L to 0.4 g/L at 25°C, under temperature conditions of 70 to 160°C, wherein the trans xanthophyll isomerized to cis xanthophyll in the contact step .
  2. A method comprising a contact step of contacting a microorganism containing trans xanthophyll with a fluid containing supercritical CO2 and an alcohol having 1 to 6 carbon atoms under temperature conditions of 70 to 160°C, wherein the trans xanthophyll isomerized to cis xanthophyll in the contact step .
  3. The method according to claim 2, wherein the alcohol is ethanol.
  4. The method according to any one of claims 1 to 3, wherein the temperature condition is 80°C to 140°C.
  5. The method according to any one of claims 1 to 4, wherein the pressure condition in the contact step is 20 MPa or more.
  6. The method according to any one of claims 1 to 5, wherein the concentration of the organic solvent or the alcohol is 15% by mass to 50% by mass with respect to the supercritical CO2 .
  7. The method according to any one of claims 1 to 6, wherein the microorganism is Paracoccus carotinifaciens.
  8. The method according to any one of claims 1 to 7, wherein the trans xanthophyll is at least one selected from the group consisting of trans astaxanthin, trans adonirubin, trans adonixanthin, trans zeaxanthin, and trans β-cryptoxanthin.
  9. A method for producing a cis-xanthophyll-containing composition, comprising a contact step of contacting a microorganism containing trans-xanthophyll with a fluid containing supercritical CO2 and an organic solvent having a solubility of astaxanthin of 0.001 g/L to 0.4 g/L at 25°C, under temperature conditions of 70 to 160°C, wherein the trans-xanthophyll isomerized to cis-xanthophyll in the contact step .
  10. A method for producing a cis-xanthophyll-containing composition, comprising a contact step of contacting a microorganism containing trans-xanthophyll with a fluid containing supercritical CO2 and an alcohol having 1 to 6 carbon atoms under temperature conditions of 70 to 160°C , wherein the trans-xanthophyll isomerized to cis-xanthophyll in the contact step .
  11. The method according to claim 9 or 10, wherein the composition comprises at least one selected from the group consisting of cis-astaxanthin, cis-adonilubin, and cis-adonixanthin.
  12. The method according to claim 11, wherein the proportion of the cis-isomer of astaxanthin in the composition is 22 area percent or more, the proportion of the cis-isomer of adonilubin is 24 area percent or more, or the proportion of the cis-isomer of adonixanthin is 22 area percent or more.
  13. The method according to any one of claims 9 to 12, wherein the microorganism is Paracoccus carotinifaciens.

Description

This invention relates to a method for isomerizing trans xanthophylls, and more specifically, to a method for isomerizing trans xanthophylls to cis xanthophylls. Xanthophylls are natural pigments widely found in nature. Known types of xanthophyll include astaxanthin, adonirubin, adonixanthin, zeaxanthin, and β-cryptoxanthin. Astaxanthin, adonirubin, and adonixanthin are known to have various effects, including anxiolytic physiological effects (Patent Document 1). Therefore, astaxanthin, adonirubin, and adonixanthin are expected to have applications in foods, pharmaceuticals, and other fields. Astaxanthin, adonirubin, and adonixanthin are widely distributed in animals, plants, and microorganisms. For example, astaxanthin is found in a wide range of natural organisms, including fish such as salmon, trout, and sea bream, and crustaceans such as crabs, shrimp, and krill. Astaxanthin is also produced by microorganisms such as bacteria belonging to the genera Agrobacterium, Brevibacterium, Paracoccus, Brevandimonas, and Erythrobacter, as well as green algae of the genus Haematococcus and yeasts of the genus Phaffia. While xanthophylls such as astaxanthin and adonixanthin are produced industrially through chemical synthesis, there is a growing demand for naturally derived forms due to increasing health consciousness and environmental awareness. Among the microorganisms mentioned above, bacteria belonging to the genus Paracoccus have advantages such as high xanthophyll productivity and rapid growth rate. An example of an astaxanthin-producing strain belonging to the genus Paracoccus is strain E-396 (FERM BP-4283: April 27, 1993 (original deposit date), National Institute of Advanced Industrial Science and Technology Patent Organism Depository Center (1-1-1 Higashi, Tsukuba City, Ibaraki Prefecture, Japan)) (Patent Document 2). On the other hand, cis-isomerization of xanthophyll is known to contribute to improved extraction efficiency from bacterial cells, and cis-isomers of xanthophyll are also known to contribute to improved absorption in the body. However, when attempting to obtain cis-type xanthophyll from microorganisms, the xanthophyll contained in microbial cells has a lower isomerization efficiency and yield compared to isomerizing the xanthophyll molecule itself, due to factors such as uptake into cell tissues like the cell membrane and interactions with biomolecules such as lipids contained in the cell. Here, Patent Document 3 describes a method for producing a tomato extract in which the cis-lycopene content is increased by further heating the lycopene-containing extract obtained by supercritical CO2 extraction from tomatoes or tomato products at a high temperature. However, the method described in Patent Document 3 is a method for increasing the cis-lycopene content by heating the extract obtained by supercritical CO2 extraction at a high temperature (110°C to 140°C), and does not mention astaxanthin. Astaxanthin is a carotenoid (particularly called xanthophyll) that has a polar hydroxyl group, and is known to have low solubility in nonpolar molecules such as CO2 , resulting in low extraction efficiency by supercritical CO2 extraction. Furthermore, paragraph 0019 of Patent Document 3 states that by employing supercritical extraction, organic solvents become unnecessary. Patent Document 4 describes a method for separating and purifying astaxanthin from cultured Phaffia rhodozyma cells, characterized by the combined use of supercritical CO2 extraction with ethanol as a cosolvent and silver nitrate aqueous solution extraction. However, the method described in Patent Document 4 involves crushing the cultured cells, pre-treating them with an organic solvent and silver nitrate, and then subjecting them to supercritical CO2 extraction, and does not directly extract xanthophyll from the cells. Furthermore, there is no mention of supercritical CO2 extraction at high temperatures, cis-trans isomerization, or content. Patent Document 5 describes a method for producing an astaxanthin concentrate by degreasing and concentrating a natural product-derived raw material (Haematococcus) containing astaxanthin using supercritical countercurrent contact extraction in a CO2 -ethanol mixed system. However, the method described in Patent Document 5 refers to supercritical CO2 extraction of astaxanthin derived from Haematococcus, and the origin of the astaxanthin is different from that of the present invention. Furthermore, in the method described in Patent Document 5, dried Haematococcus is added to ethanol, and the insoluble matter is filtered out and subjected to supercritical CO2 extraction; astaxanthin is not extracted directly from the dried material. Moreover, astaxanthin derived from Haematococcus is specifically in the ester form, while astaxanthin derived from Paracoccus bacteria exists as a free form. Free form astaxanthin is known to have lower solubility and be more difficult to extract than ester form astaxanthin.