Astaxanthin

The red ketocarotenoid that the freshwater microalga Haematococcus pluvialis builds up under stress is the source of this astaxanthin, which is isolated from the dried algal biomass by solvent extraction and purification. In the cell it occurs mostly as fatty-acid esters of the (3S,3’S) form, a xanthophyll with a hydroxyl and a keto group on each end ring.

The primary grade is 10% astaxanthin by HPLC, with a 5% grade also supplied, in Food / Dietary Supplement Grade. The dark red powder is insoluble in water. Both grades are formulated powders in which the carotenoid is a share of the material, so the percentage and the method decide how a lot is used.

SKU: BOT-PHY-0015 Category: Phytochemicals Tags: Carotenoids, Dry Blends & Premixes, Plant Compounds, Seaweed & Algae, Softgels & Oil Fills, Solvent Extracted

Astaxanthin Chemical Identity

Astaxanthin has the molecular formula C40H52O4 and a molecular weight of 596.8. The backbone is a long conjugated polyene chain between two six-membered end rings, and the chain absorbs strongly in the blue-green range, which explains the deep red color. Each end ring carries a hydroxyl and a keto group, and those groups make astaxanthin a xanthophyll rather than a plain carotene such as lycopene.

The natural source is the whole alga Haematococcus pluvialis Flot. When light, salt or nutrient stress hits the cell, it forms a thick-walled resting spore and fills it with esterified astaxanthin. The molecule behind the (3S,3’S) designation is the stereoisomer that the alga makes. Synthetic astaxanthin exists as a mixture of stereoisomers, so stating the natural source tells a buyer which composition to expect. The whole algal biomass is supplied separately as Haematococcus pluvialis Powder, which keeps the pigment inside the cell and is a different ingredient from the isolated carotenoid. Breaking the thick cell wall is the step that releases the pigment, and whole algal powder and isolated astaxanthin therefore behave differently in a formula. Both are produced from the same alga, and the choice depends on whether a defined carotenoid content or the whole biomass is wanted.

Typical Specifications

Specification Item	Product Information
Natural Source	Haematococcus pluvialis whole algae
Plant Part	Seaweed & Algae
Processing	Solvent Extraction & Purification
Compound Class	Carotenoids
Chemical Name (IUPAC)	(6S)-6-hydroxy-3-[(1E,3E,5E,7E,9E,11E,13E,15E,17E)-18-[(4S)-4-hydroxy-2,6,6-trimethyl-3-oxocyclohexen-1-yl]-3,7,12,16-tetramethyloctadeca-1,3,5,7,9,11,13,15,17-nonaenyl]-2,4,4-trimethylcyclohex-2-en-1-one
CAS Number	472-61-7
Molecular Formula	C40H52O4
Molecular Weight	596.8
PubChem CID	5281224
InChIKey	MQZIGYBFDRPAKN-UWFIBFSHSA-N
SMILES	CC1=C(C(CC(C1=O)O)(C)C)C=CC(=CC=CC(=CC=CC=C(C)C=CC=C(C)C=CC2=C(C(=O)C(CC2(C)C)O)C)C)C
Purity	10% (HPLC)
Available Grades	5% · 10% (HPLC)
Grade	Food / Dietary Supplement Grade
Appearance	Dark Red powder
Solubility / Dispersibility	Insoluble in Water
Quality Parameters
Moisture (LOD)	≤5.0%
Total Ash	≤5.0%
Heavy Metals	Lead ≤2 ppm · Arsenic ≤1 ppm · Cadmium ≤1 ppm · Mercury ≤0.1 ppm
Microbiology	TPC ≤1,000 cfu/g · Yeast & Mold ≤100 cfu/g · E. coli Negative · Salmonella Negative/25 g
Shelf Life	24 months in unopened original packaging, cool and dry storage

Astaxanthin Purity Grades & Impurities

Grade	Assay & Method	Where It Fits
5% Astaxanthin	HPLC	Premixes and oil dispersions
10% Astaxanthin	HPLC	Capsule fills with a small dose volume

The two grades differ in how much carotenoid a gram of powder carries, not in the identity of the pigment. A percentage here is a content figure for a formulated material, which is why the grades sit far below the purity of a crystalline compound. HPLC quantifies astaxanthin against a reference and may report free and esterified forms after a hydrolysis step, so the report should state whether esters are counted as astaxanthin.

The related substances of an algal carotenoid are the other xanthophylls and carotenes of the cell. Canthaxanthin, adonirubin, adonixanthin and beta-carotene are named in the literature as accompanying pigments, and the cis-isomers of astaxanthin appear when the pigment is heated or lit. Chlorophyll residues and algal lipids are also looked for, because the cell is oil-rich. Oxidation is the main quality risk, since the long polyene chain bleaches in light and air. A lot that has faded from deep red toward orange has lost pigment, and the HPLC area for astaxanthin falls accordingly.

Identity is confirmed by the retention time and the visible absorption spectrum of the main peak against a reference. This separates astaxanthin from the other keto-carotenoids that elute nearby. Because the 5% and 10% grades are powders and not crystals, the matrix also matters. A lot that is hard to wet, or that releases oil on standing, has a different physical profile even when the HPLC content is identical, so appearance and flow are checked next to the percentage.

Astaxanthin Solubility & Delivery

Astaxanthin is insoluble in water and dissolves in organic solvents and oils, although its solubility in edible oils is limited. The rigid, linear molecule crystallizes readily, so the pigment is carried in the powder as a dispersion or inside a protective matrix and not as free crystals. In water, the powder wets slowly and forms a red suspension that settles unless an emulsifier or hydrocolloid is used.

Delivery approaches in principle are oil solutions with antioxidants, emulsions, microencapsulation and cyclodextrin or protein complexes. Each reduces contact with oxygen and light, which matters because the pigment degrades quickly when it is exposed. Heat steps shift the stereochemistry toward cis-isomers and lower the stability of the esters. Opaque containers, nitrogen flushing and low storage temperatures protect the color, and a retained sample of each lot lets the formulator track fading.

Particle size and the wetting agent decide how evenly the powder spreads in an oil or an emulsion. Pre-dispersing it in a warm carrier oil, then adding it to the bulk, avoids red lumps, and a short trial under the intended lighting shows how the pigment ages in the finished product before the process is scaled up.

Application Areas

Softgel Oil Fills

Softgels carry astaxanthin as an oil dispersion with an antioxidant such as tocopherol. The red pigment stains tooling, so a dedicated line, a nitrogen blanket and opaque storage of the fill keep the color and the next product clean.

Capsule Fills of the 10% Powder

The 10% grade fills capsules at a small weight. The powder is sticky when warm, so a cool room and a flow agent help, and amber or opaque capsules slow the loss of red color on the shelf.

Dry Premixes at the 5% Grade

The 5% grade suits dry premixes where weighing accuracy matters at low inclusion. Premix it in two steps with a dry carrier, sieve the blend to avoid red specks in the final powder, and keep the pack closed between uses because moisture dulls the color.

Oil-Phase and Emulsion Systems

Beverage emulsions and oil-phase formulations use the powder after dispersion in a carrier oil. Particle size and emulsifier choice decide hue and stability, and a trial under light exposure shows the fade rate before scale-up.

Packaging & Commercial Supply

Essencefield supports product evaluation, formulation trials, commercial orders, and ongoing ingredient supply. Packaging, storage, and shipping arrangements are determined by product characteristics, order quantity, stability requirements, and destination-market needs.

Supply Item	General Information
Sample	Available upon request for formulation, testing, and supplier evaluation
Order Quantities	100 g · 1 kg · 5 kg · 25 kg · 100 kg · 500 kg · Bulk
Sample Lead Time	Typically 5–7 days after sample confirmation
Production Lead Time	Typically 15–30 days after order and specification confirmation
Packaging	Suitable protective inner packaging with bags, cartons, drums, or other appropriate outer packaging
Storage	Store in tightly sealed, suitable protective packaging in a cool, dry environment. Protect from moisture, heat, and direct sunlight. Specific storage conditions follow the approved product specification.
Documentation	COA · Product Specification · TDS · SDS · Applicable declarations (as applicable)

Final order quantities, lead times, packaging, documentation, and shipping arrangements are confirmed according to the selected product and commercial requirements.