Process for isolating a carotenoid from a carotenoid-producing bioorganism

Abstract

The present invention relates to an improved process for isolating a carotenoid from a carotenoid-producing bioorganism, as well as to a formulation comprising such a carotenoid, and the use of such a solid formulation in feed products (or pre-mixes).

Claims

1. A process for isolating a carotenoid from a carotenoid-producing bioorganism comprising the following steps: (i) extracting a carotenoid from a biomass comprising a carotenoid-producing bioorganism by bringing the biomass into contact with at least one organic solvent (I) to obtain a carotenoid-containing organic solvent solution, (ii) optionally conducting at least one solvent washing step of the carotenoid-containing organic solvent solution using at least one solvent (II) which is immiscible with the solvent (I) to obtain a washed carotenoid-containing organic solvent solution, and (iii) optionally drying the washed carotenoid-containing organic solvent solution obtained according to step (ii), wherein the process further comprises after step (i) the step of: (i) conducting at least one acid washing step of the carotenoid-containing organic solvent solution by contacting the carotenoid-containing organic solvent solution with an aqueous acidic solution comprising at least one Brnsted acid selected from the group consisting of citric acid, tartaric acid and maleic acid to obtain an acid-washed carotenoid-containing solution.

2. The process according to claim 1, wherein the aqueous acidic solution comprises the Brnsted acid in a concentration of between 0.5-10 wt-%, based on total weight of the aqueous acidic solution.

3. The process according to claim 1, wherein the process is carried out batchwise or continuously.

4. The process according to claim 1, wherein step (i) is carried out at a temperature below a boiling point of the solvent (I).

5. The process according to claim 1, wherein step (i) is practiced by extracting the carotenoid from the biomass with at least one water-immiscible organic solvent as the solvent (I).

6. The process according to claim 5, wherein the water-immiscible organic solvent is at least one selected from the group consisting of CH.sub.2Cl.sub.2, chloroform, n-heptane and n-hexane.

7. The process according to claim 1, wherein the at least washing step (ii) is carried out after step (i) and before and/or after step (i).

Description

EXAMPLES

(1) The following examples have been prepared as described in the description.

Example 1

Acetylated Astaxanthin

(2) The biomass (Yarrowia lipolytica) was extracted with CH.sub.2Cl.sub.2. The so obtained solution which comprised the acetylated astaxanthin was washed with approximately double the amount of deionized water. The water phase was discarded. This washing step was repeated.

(3) The so obtained solution was washed with an aqueous solution (3 wt-%) of citric acid.

(4) Afterwards the citric acid solution was discarded.

(5) The so obtained solution comprised about 1,6 wt-% (based on the total weight of the solution) of acetylated astaxanthin.

(6) This solution was used to form an emulsion (with lignosulfonate as emulsifier). This emulsion was stable also after removal of the (organic) solvent and spray drying.

Example 2

Acetylated Astaxanthin

(7) The biomass (Yarrowia lipolytica) was extracted with CH.sub.2Cl.sub.2.

(8) This solution was divided into 3 portions and they were all washed with citric acid and after wards the solutions were combined and washed again with citric acid.

(9) This solution was used to form an emulsion (with lignosulfonate as emulsifier). This emulsion was also stable after removal of the (organic) solvent and spray drying.

Example 3

Comparative Example

Acetylated Astaxanthin

(10) The biomass (Yarrowia lipolytica) was extracted with CH.sub.2Cl.sub.2.

(11) No citric acid washing step was carried.

(12) The so obtained solution was intended to form an emulsion (with lignosulfonate as emulsifier).

(13) No stable emulsion was obtained and it was not possible to use this emulsion for further formulations.