Marine Proteins & Peptides

Global seafood processing generates on the order of 80 million tonnes of by-product a year, and a large share of it — heads, frames, trimmings, viscera, shell — is still written off rather than sold. The protein sitting in those streams can make up about 60% of their dry weight, and it is not low-grade protein: fish muscle carries the full essential amino acid set, crustacean material is rich in glutamic acid, glycine and arginine, and microalgae hold anywhere from a quarter to well over half their dry mass as protein. Turning that into a specification sheet rather than a disposal cost is what this whole category is for.

Eata Marisource works those streams into seven product families, from bulk fish protein ingredients through species-specific peptides and fermentation peptones to nucleic acid fractions. The split is not cosmetic. A peptone sold into a fermentation plant is judged on amino nitrogen, a shrimp peptide sold into a bioactivity programme is judged on chain length and assay response, and an algal protein is judged on how well the cell wall was opened. We describe every one of them by the parameters that decide whether it works, and we report those parameters per lot.

The Streams We Draw From

Four raw material families feed the catalogue, and each arrives with its own handling clock. Marine fish frames and trimmings come from filleting lines and are processed fresh or frozen at sea. Crustacean streams — shrimp, crab and Antarctic krill — carry both protein and shell, which means a demineralisation decision has to be made early. Microalgae arrive as harvested slurry or dried biomass from controlled culture. Milt and roe processing side streams supply the nucleic acid work. Nothing in this list is fished for its own sake; all of it exists before we touch it.

One Platform, Seven Families

Below is the practical map of the category. The middle column lists the numbers customers actually specify against, which is why it differs so much from row to row:

Hydrolysis Decides Almost Everything

Two products made from the same fish can behave like different materials, and the difference usually comes down to three process choices: which protease was used, how far the reaction was allowed to run, and what happened to the hydrolysate afterwards. Enzyme selection sets where the chain breaks, because a protease cuts only at the residues it recognises. Degree of hydrolysis sets average chain length, solubility and — past a certain point — bitterness, since the peptides responsible for bitter notes are the short hydrophobic ones. Downstream refining sets colour, salt load and odour.

• Enzyme choice — Alcalase for broad, deep hydrolysis; papain, bromelain and fungal proteases where a  milder cut is wanted; flavourzyme when bitterness has to be kept low
• Process control — pH and temperature are held, not guessed, and the reaction is quenched by heat or pH shift at a defined point rather than when the tank looks right
• Refining — centrifugation, filtration, carbon or resin polishing, and concentration or drying close the loop; each step is chosen against the target specification, not applied by default

Peptides: Length Is the Variable That Matters

Bioactive marine peptides typically run from three to forty residues, and most of the interesting ones sit between two and twenty. Enzyme choice and parent protein decide the sequence; sequence decides the activity; chain length decides whether the molecule survives formulation and reaches anything intact. That is why molecular weight windows are quoted on our peptide grades rather than a single average — a 3 kDa cut and a 10 kDa cut of the same hydrolysate are different products with different behaviour.

Short fractions generally dissolve faster, taste cleaner and move more easily through a matrix. Longer fractions tend to hold functional properties like emulsification and film formation. Where a customer needs a specific activity, we cut to a window, screen it, and ship the assay result alongside the material rather than describing it in adjectives.

Nucleic Acids and Nucleotides: The Overlooked Stream

Milt and roe processing leaves behind material that most plants never value: DNA-rich and RNA-rich fractions, and the 5'-nucleotides that give seafood its savoury depth. We recover those as nucleic acid preparations, nucleotide blends and nucleoside fractions, specified on content, nucleotide profile, salt form and moisture. Two very different customers use them — molecular biology and cell culture groups that need clean nucleic acid, and flavour researchers chasing the savoury note that inosine and guanosine monophosphates carry.

Algal Protein: Break the Wall Before Anything Else

Microalgae hold their protein behind a wall, and no amount of good hydrolysis will help if that wall is intact. Chlorella species in particular need mechanical disruption — bead milling or high-pressure homogenisation — before the protein becomes accessible; Spirulina is far easier to open. Reported protein contents for Chlorella, Tetraselmis and Dunaliella span roughly 25–57% of dry mass, and processed Spirulina preparations run higher. Which disruption route we use depends on whether you want the pigment too: phycobiliproteins such as C-phycocyanin are proteins in their own right, and a harsh extraction that denatures them turns a two-product stream into one.

Peptones: The Fermentation Side of the House

A peptone is judged by one question: how fast and how densely does your organism grow on it. Marine peptones answer that better than expected. Published comparisons report maximum growth rates two to three times higher than on beef peptone and final biomass close to double, and commercial fish peptone specifications typically sit at total nitrogen of 13–15% with amino nitrogen around 2–2.5%, moisture under 8% and solution pH near neutral. Lactobacillus, Escherichia and yeast cultures all respond well, and because the material comes from marine streams no mammalian input enters the medium.

We supply bacteriological, biochemical and industrial grades, and we will tell you which one suits your organism instead of pushing the highest grade by default. Solubility after sterilisation, clarity of a 2% solution and chloride load matter more in practice than any single nitrogen figure.

The Data Set That Travels With Each Lot

Whatever the family, the release data follows the same logic — measure what governs performance, then print it:

• Protein and hydrolysis — protein content by Kjeldahl or Dumas, and degree of hydrolysis where the material is hydrolysed
• Chain length — molecular weight distribution by size-exclusion chromatography for every peptide grade
• Fermentation metrics — total and amino nitrogen for peptones, with the ratio stated
• Composition — amino acid profile, salt, ash, fat, moisture, and the pH of a defined solution
• Handling behaviour — solubility across pH, colour and odour assessment, and clarity after heat treatment
• Special cases — nucleic acid content and nucleotide profile for the nucleic acid grades; heavy metals and microbial counts reported where your application calls for them

What Customers Actually Build With Them

• Food and nutrition research — protein enrichment, texture systems, emulsion and foam stabilisation, and savoury base development in food research
• Fermentation — nitrogen sources for antibiotics, enzymes, amino acids, vitamins and probiotics at industrial fermentation scale
• Bioactivity programmes — species-specific peptides for bioactivity screening, and functional fractions for cosmetic actives
• Aquaculture nutrition — high-value feeds for fry and broodstock, where marine protein is the one ingredient the animal already recognises
• Research reagents — nucleic acid preparations, culture media components and biochemical reagents for laboratory supply

Where a Standard Grade Stops Being Enough

Most conversations here start from a process rather than a product code, because the variables multiply quickly. These are the ones we adjust most often:

• species and raw stream — fish, crustacean, mollusc or microalgal, fresh, frozen or dried intake
• enzyme system and degree of hydrolysis, set against the functional property you need rather than a target number alone
• molecular weight window, cut by ultrafiltration and confirmed by chromatography
• refining level — decolourised, deodorised, desalted or demineralised, each costing yield and each worth it for the right application
• physical format: liquid concentrate at agreed solids, spray-dried powder, agglomerated or fine grind, low-dust grades for plant handling
• blends — marine peptones combined with yeast extract or mineral salts, peptide fractions blended to a target activity, proteins co-dried with other marine polymers
• pack scale from laboratory bottles to bulk bags and drums, with lot traceability back to the receiving plant

Tell us the organism, the matrix or the assay your material has to satisfy, and we will build the grade around that answer.

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