The phrase "algae extract" is a general term encompassing a vast array of compounds derived from aquatic organisms. Due to the immense diversity of algae—which range from microscopic, single-celled organisms to large seaweeds—there is no single, universal name for the extracts. The specific name often indicates the source, the type of molecule extracted, or its intended function in a product. For instance, a thickening agent derived from red algae will be named differently than a blue-colored pigment from a type of cyanobacteria.
The Many Names and Sources of Algae Extracts
The name for an algae extract is most commonly determined by the species of algae it is derived from and the specific compound isolated. The four major classes of algae—brown, red, green, and blue-green—each yield different types of extracts with unique properties.
Extracts from Brown Algae (Phaeophyceae)
Brown algae, which include seaweeds and kelps, are a prolific source of valuable extracts.
- Alginate: This is a family of anionic polysaccharides with gelling, thickening, and stabilizing properties, widely used in the food and pharmaceutical industries. Common sources include Laminaria hyperborea and Macrocystis pyrifera.
- Kelp Extract: A general term for extracts from kelp species, rich in minerals and vitamins. It is commonly used in nutritional supplements and cosmetics for its moisturizing and soothing properties.
- Fucoidan: A sulfated polysaccharide with reported anti-inflammatory and antioxidant activities, primarily found in brown seaweeds like Fucus vesiculosus.
Extracts from Red Algae (Rhodophyceae)
Red algae provide important gelling and thickening agents for various commercial products.
- Carrageenan: Extracted from red seaweeds, carrageenans are a family of linear sulfated polysaccharides used as thickeners, gelling agents, and stabilizers in dairy products, plant-based milks, and processed foods. A common source is Chondrus crispus, known as Irish Moss.
- Agar: Another gelling agent, agar is a gelatinous polysaccharide used in food products and as a culture medium in microbiology. It is also derived from red algae.
Extracts from Green Algae (Chlorophyta)
Often used in nutritional supplements and skincare, green algae offer a wealth of nutrients.
- Chlorella Vulgaris Extract: A specific extract from the unicellular microalgae Chlorella vulgaris. It is rich in amino acids, fatty acids, and vitamins, and is marketed for its skin-regenerating and antioxidant properties.
Extracts from Blue-Green Algae (Cyanobacteria)
Despite being bacteria, these organisms are often categorized with algae due to their photosynthetic nature and the pigments they produce.
- Phycocyanin: A vibrant blue pigment-protein complex found in cyanobacteria, such as Spirulina and Aphanizomenon flos-aquae. It is a potent antioxidant used as a natural blue food coloring and in supplements.
- Spirulina Extract: A broad term for extracts from Arthrospira platensis (spirulina), valued for its high protein content, vitamins, and minerals.
Specialized Algae-Derived Compounds
Beyond the general classifications, certain high-value molecules are isolated and named individually.
- Astaxanthin: This reddish carotenoid pigment is derived from microalgae like Haematococcus pluvialis and is renowned as an extremely powerful antioxidant, widely used in supplements for eye and skin health.
Comparison of Common Algae Extracts
| Feature | Alginate | Carrageenan | Phycocyanin |
|---|---|---|---|
| Source | Brown seaweed (Phaeophyceae) | Red seaweed (Rhodophyceae) | Blue-green algae (Cyanobacteria) |
| Primary Function | Gelling, thickening, stabilizing | Gelling, thickening, emulsifying | Natural blue coloring, antioxidant |
| Key Application | Food (jams, sauces), pharmaceuticals, wound dressings | Food (ice cream, dairy alternatives), cosmetics | Food coloring, dietary supplements, cosmetics |
| Chemical Type | Anionic polysaccharide | Sulfated polysaccharide | Pigment-protein complex |
| Gel Properties | Forms strong, irreversible gels with calcium ions | Forms various gels (kappa, iota) depending on type | N/A (acts as a pigment and protein) |
The Extraction and Processing of Algae
Producing an "algae extract" is a multi-step process that can significantly influence the final product. The raw biomass is first harvested, dried, and ground. For many extracts, a solvent-based extraction is used to dissolve the desired components. For example, sodium alginate is extracted from dried seaweed using hot water and sodium carbonate, followed by filtration and precipitation. Phycocyanin is often extracted from Spirulina biomass using water or buffer solutions. The subsequent purification steps, such as precipitation with alcohol or salts, further define the extract's properties, purity, and eventual application. For instance, cosmetic-grade algae extract will undergo different purification processes than a food-grade gelling agent. These processes are critical for removing impurities and concentrating the beneficial compounds.
Conclusion
In conclusion, asking what is algae extract called is akin to asking what is a plant extract called—the answer is specific to the source and compound. The general term covers a wide spectrum of natural ingredients, with names like alginate, carrageenan, kelp extract, and phycocyanin referring to specific types derived from brown, red, and blue-green algae. The terminology reflects the extract's origin and function, from thickening foods to providing potent antioxidants for health. The diversity of algae offers a rich resource for various industries, and understanding the specific name provides clarity on a product's composition and benefits.
For a deeper look into the biomedical applications of these compounds, refer to the National Institutes of Health.
