Algal Protein Hydrolysates & Peptides

A microalga does not give up its protein politely. Chlorella wraps its contents in a wall built to survive digestion, and the red seaweed Palmaria palmata shields its remarkably complete amino-acid profile behind a rigid skeleton of mixed-linkage xylans. Whatever an algal hydrolysate eventually becomes, the quality was decided earlier — in the minutes when that wall was opened and in the extraction that followed. Open it clumsily and the protein emerges denatured, stained and partly degraded; open it well and alkaline extraction has been reported to deliver around 82 per cent protein from Spirulina and about 72 per cent from Chlorella vulgaris, figures that compete with conventional plant isolates.

Eata Marisource supplies the hydrolysates that come out the other side of that step. Microalgal streams — Arthrospira, Chlorella, Nannochloropsis, Tetraselmis, Haematococcus — and macroalgal streams — Palmaria, Ulva, Saccharina, Undaria, Porphyra — are disrupted, extracted, hydrolysed with a chosen protease and cut to a declared molecular-weight window. Decolourised grades, sequence-characterised fractions and spray-dried or liquid formats are all within the same production family.

Opening the Cell

Disruption is where the yield is won, and no single method wins everywhere. Rigid-walled Chlorella tolerates beating where thin-walled Arthrospira does not, and a seaweed whose wall is a xylan network answers to enzymes rather than to shear. The route we recommend depends on the organism and on what the downstream application can tolerate in terms of heat, salt and residual pigments.

Disruption route	Best suited to	What it buys you	What it costs you
High-pressure homogenisation	Thin-walled microalgae, wet paste	Scales cleanly, short residence time	Heat load needs control; several passes for tough cells
Bead milling	Rigid-walled Chlorella and Nannochloropsis	Highest disruption efficiency per pass	Media wear and downstream clarification
Ultrasound assistance	Seaweed and microalgal slurries	Sharp yield gains and much shorter extraction times	Energy cost at scale; needs well-defined geometry
Enzymatic wall attack	Xylan-walled red seaweeds such as Palmaria	Gentle, preserves protein quality, lower pigment release	Enzyme cost and longer cycle
Freeze-thaw and osmotic shock	Delicate biomass, research-scale lots	No added chemicals, very mild	Slow, energy-heavy, hard to scale

Row of tall glass tubular photobioreactors filled with dense green microalgae culture in a cultivation facility.

Tubular photobioreactors produce the consistent biomass that steady peptide specifications depend on.

Grades and Specifications

Five grades cover most briefs, and each can be pinned to a tighter molecular-weight window on request.

Grade	Source streams	Cut window	Typical specification points
Algal protein isolate	Microalgal and macroalgal biomass	Intact, >10 kDa retained	Protein by amino-acid summation; solubility and water-holding reported
Microalgal peptide hydrolysate	Arthrospira, Chlorella, Nannochloropsis	Predominantly <3 kDa	Degree of hydrolysis, peptide content, antioxidant assay values
Macroalgal peptide hydrolysate	Palmaria, Ulva, Saccharina, Undaria	<10 kDa and sub-fractions	ACE inhibition, ORAC, precursor proteins identified by LC-MS/MS
Decolourised peptide grade	Any of the above	<3 kDa clarified	Pigment reduced to a stated level; pale powder or clear solution
Sequence-characterised fraction	Targeted enzyme–substrate pairings	<1 kDa tight cut	Identified di-, tri- and oligopeptides with assay-level documentation

Stainless steel disc stack centrifuge separator with pipework in a microalgae processing plant.

Intact and ruptured microalgal cells: the difference a disruption step makes.

Figures From the Published Record

Algal peptides have been characterised enough that specifications can be written against measured behaviour rather than general claims. A sample of what has been reported:

Antioxidant strength hydrolysates dominated by sub-3 kDa peptides reached 78 per cent DPPH scavenging, 82 per cent ABTS and 74 per cent ferric-reducing activity, with an ABTS IC50 as low as 23.44 µg/mL for Chlorella vulgaris.
Skin-enzyme inhibition the same fractions inhibited elastase by 84 per cent, collagenase by 90 per cent and tyrosinase by 66 per cent — the reason cosmetic researchers keep returning to algal hydrolysates.
Sequences on record mass spectrometry of those fractions turned up short sequences such as Lys-Val, Val-Arg, His-Ile, Lys-Leu, Ile-Leu, Leu-Phe, Tyr-Phe and Leu-Gly-Leu.
Antihypertensive activity protease N hydrolysates of Chlorella sorokiniana returned an ACE IC50 of 0.035 mg/mL, while classic seaweed work reported Ile-Trp at 1.5 µM and Ile-Tyr at 6.1 µM from wakame digests.
Red seaweed performance a chymotrypsin hydrolysate of Palmaria palmata below 10 kDa showed 67.7 per cent ACE inhibition at 5 mg/mL and an oxygen-radical absorbance capacity near 441 µmol trolox equivalents per gram, with RuBisCO, allophycocyanin and phycocyanin identified among the precursor proteins.

Thick dark green microalgal biomass paste in a glass beaker with a steel spatula lifting it.

Controlled enzymatic hydrolysis running at fixed temperature, pH and agitation.

Reporting Protein Honestly

One number deserves a warning. Protein content in this sector is usually calculated as nitrogen multiplied by 6.25, and for macroalgae that shortcut is generous. When conversion factors were calculated fraction by fraction for Palmaria palmata, every one of them came out materially below 6.25, meaning the familiar factor systematically overstates the protein in processed dulse. Since non-protein nitrogen — pigments, free amino acids, nucleic acids — inflates the nitrogen figure, our certificates state protein by amino-acid summation as well as by nitrogen, and we will tell you plainly which figure to use for labelling and which for formulation.

Colour, Taste and Handling

Chlorophyll and phycobiliproteins are the reason an algal hydrolysate can arrive looking like pond water. Where the application allows it we keep the pigment, because it carries antioxidant value; where it does not, a decolourisation step brings the material to a pale gold solution or an off-white powder without stripping the low-molecular-weight peptides that carry the activity. Bitterness follows the usual rules — deeper hydrolysis exposes more hydrophobic residues — and is managed through enzyme choice, degree of hydrolysis and, if needed, a resin or carbon polish. Desalting keeps ash low, which matters for both taste and shelf stability.

Glass flasks of green algal suspension held in a shaking water bath with temperature and pH probes.

Unrefined hydrolysate beside the same material after decolourisation.

Quality Panel

Every lot ships with the following, not merely a protein percentage:

molecular-weight distribution by size-exclusion chromatography, with the percentage below each declared cutoff.
degree of hydrolysis and free amino-acid content for the hydrolysate grades.
full amino-acid profile including the essential residues, which is also the basis of our protein figure.
assay results matched to your brief — DPPH, ABTS, FRAP, ORAC, ACE inhibition — where the grade is sold on activity.
pigment level, ash, moisture, microbiology and heavy metals, with residual solvent reported when organic extraction is used.

Two glass bottles side by side showing dark green hydrolysate next to a pale golden clarified solution.

Harvesting the culture: centrifuges concentrate dilute algal suspensions into workable paste.

Where Algal Peptides Are Working

cosmetic and dermal research, where elastase and collagenase inhibition is the purchasing criterion.
antioxidant and anti-glycation systems for beverages, powders and clear-format drinks using decolourised grades.
fermentation and cell-culture nutrition as a defined peptide nitrogen source with a traceable amino-acid profile.
aquaculture and pet-food formulations that need digestible marine-origin protein at low inclusion rates.
analytical and screening programmes that want organism-specific hydrolysates from a single, verifiable biomass batch.

Light micrograph of small spherical green microalgal cells with some cell walls ruptured.

Dense harvested biomass paste entering extraction.

Custom Development

Organism, cultivation record, disruption route, enzyme system, molecular-weight cutoff and pigment level are all selectable, and a validated combination can be locked over repeat lots so that a fraction proven in early screening behaves identically at pilot scale. If your programme targets a published sequence or a specific assay threshold, we can reproduce the reported conditions and document the outcome. Co-blends with other marine ingredients from our range are available for formulation trials.

Request a Quotation

Tell us the organism, the molecular-weight window and the assay your work depends on, and our team will respond with current specifications, documentation and pricing.

For Research or Industrial Raw Materials, Not For Personal Medical Use!