Sodium Alginate
Thickeners
Emulsifiers
9005-38-3
E401
(C₆H₇NaO₆)ₙ
$9.50 ~ $14.25
Food
Free sample from 100g(NF)
One unit of:25kg/bag
One unit of:25kg/bag
25kg/bag
Product Info
What is Sodium Alginate?
Sodium alginate is a natural polysaccharide derived from brown seaweed, highly valued in the food industry as a versatile hydrocolloid for thickening, stabilizing, and forming strong, heat-stable gels, most notably in molecular gastronomy techniques like spherification.
How is Sodium Alginate made?
| Step No. | Production Stage | Key Action | Control Point & Note |
|---|---|---|---|
| 1 | Raw Material Preparation | Wash, chop, and pre-treat raw brown seaweed with dilute acid (e.g., H₂SO₄). | Removes soluble salts (e.g., fucans), sand, and other impurities. Acid concentration and treatment time are controlled to avoid degrading the target alginate polymer. |
| 2 | Alkaline Extraction | Digest the treated seaweed in a hot Sodium Carbonate (Na₂CO₃) solution to solubilize the alginate. | This key step converts insoluble alginic acid into soluble sodium alginate. Temperature, alkali concentration, and digestion time are critical to maximize yield while preventing polymer degradation, which dictates final product viscosity. |
| 3 | Clarification & Filtration | Dilute the viscous digestate with water and filter or centrifuge to remove insoluble seaweed residue (cellulose). | The goal is a clear, cell-free filtrate. Dilution is necessary to lower viscosity for effective separation. The clarity of the solution directly impacts the purity and color of the end product. |
| 4 | Precipitation | Add Calcium Chloride (CaCl₂) or a strong acid to the clear filtrate. | Precipitates the alginate from the solution as insoluble Calcium Alginate fibers or Alginic Acid gel. Precise pH control (for acid method) or ion concentration is crucial for complete precipitation and good fiber formation for washing. |
| 5 | Conversion & Purification | Wash the precipitate thoroughly and then treat it with a sodium-based alkali (e.g., Na₂CO₃) to convert it back to Sodium Alginate. | This ion-exchange step removes the calcium and creates a pure sodium alginate paste. Thorough washing before this step is vital to remove impurities. |
| 6 | Dehydration & Drying | Precipitate the purified sodium alginate from its paste form using alcohol (e.g., isopropanol), then press and dry the resulting fibers. | Alcohol efficiently removes water. The drying temperature and time must be carefully controlled to achieve the target moisture content (typically <15%) without causing thermal degradation of the polymer. |
| 7 | Milling & Blending | Mill the dried fibrous product into a powder of a specified particle size. Blend different batches as needed. | Milling achieves the desired powder form and dissolution characteristics. Blending ensures lot-to-lot consistency. Final QC confirms viscosity, purity, particle size (mesh), heavy metal levels, and microbial counts meet specifications. |
Technical Specifications
| CAS Number | 9005-38-3 |
| Chemical Formula | (C₆H₇NaO₆)ₙ |
| Solubility | Soluble in cold & hot water; insoluble in ethanol, ether, chloroform, acids pH<3 |
| Storage Conditions | Store sealed at room temperature, dry, avoid humidity |
| Shelf Life | 36 Months |
Applications & Usage
Common Applications:
Ice‑cream
sauces
bakery fillings
spherification
meat products
pharmaceuticals
textile printing
pet foods
Mechanism of action:
| Parameter | Sodium Alginate |
|---|---|
| Functional Category | Gelling Agent; Thickener; Stabilizer; Emulsifier |
| Key Ingredients | Sodium Alginate (Sodium salt of alginic acid, a polysaccharide extracted from brown seaweed) |
| Mechanism of Action | Long-chain anionic polysaccharide forms viscous solutions by entangling polymer chains. In the presence of divalent cations (e.g., Ca²⁺), guluronic acid blocks cross-link via an 'egg-box' model, creating a thermally irreversible hydrogel network that entraps water and other components. |
| Application Effect in Product | Forms heat-stable gels upon addition of calcium salts (e.g., restructured foods); increases viscosity and provides shear-thinning properties in liquids (sauces, dressings); stabilizes foams and emulsions; controls ice crystal formation in frozen desserts; provides controlled moisture release. |
Comparison:
| Product Name | Category/Type | Key Features | Strengths (vs peers) | Weaknesses (vs peers) | Best Use Cases | Why Choose |
|---|---|---|---|---|---|---|
| Sodium Alginate | Seaweed-derived hydrocolloid | Forms irreversible, heat-stable gels in the presence of calcium ions. | Unique ability to form spheres and ravioli (spherification). Gels do not melt when heated. | Requires a specific ion (calcium) to gel. Gel texture can be rubbery if not properly controlled. | Molecular gastronomy (spherification), heat-stable fruit fillings, thickener for dyes. | For creating unique textures like edible pearls or for gels that must withstand high temperatures. |
| Xanthan Gum | Fermentation-derived polysaccharide | High viscosity at very low concentrations. Stable across a wide pH and temperature range. | Excellent thickener and emulsion stabilizer. Hydrates in hot or cold water. Very reliable and easy to use. | Does not form a solid gel on its own. Can create a slimy texture in high concentrations. | Gluten-free baking, thickening sauces and dressings, preventing separation in beverages. | For reliably thickening liquids and stabilizing emulsions without forming a gel. |
| Agar-Agar | Seaweed-derived hydrocolloid | Forms firm, brittle, thermoreversible gels. Melts at ~85°C (185°F). | Strongest gelling power. Creates very firm, clear gels. Excellent vegan substitute for gelatin. | Must be boiled to dissolve. Gels can be brittle and release water (syneresis). | Vegetarian jellies and desserts, microbiological plating, firm dessert gels. | For creating firm, heat-resistant, vegan gels with a clean, brittle texture. |
| Carrageenan (Iota/Kappa) | Seaweed-derived hydrocolloid | Forms gels with specific ions (calcium, potassium). Reacts strongly with milk proteins. | Creates a wide range of textures from soft and elastic (Iota) to firm and brittle (Kappa). Ideal for dairy. | Can impart a slight flavor. Some types require heat to dissolve. | Dairy desserts (flan, panna cotta), stabilizing chocolate milk, vegan cheese, soft elastic gels. | For gelling dairy-based products or for creating specific elastic or firm gel textures. |
| Guar Gum | Plant seed-derived gum | Rapidly hydrates in cold water to create high viscosity. | Very effective and economical cold-process thickener. Prevents ice crystal growth in frozen foods. | Does not form a gel. Can have a "beany" off-flavor in high concentrations. | Thickening cold sauces, ice cream, smoothies, and processed foods. | For cost-effective thickening of cold preparations where a gel is not desired. |
| Pectin | Plant-derived polysaccharide | Forms soft gels in specific conditions, requiring high sugar content and low pH (acid). | Creates the classic texture of jams and jellies. Excellent flavor release. | Gelling is highly conditional and dependent on sugar/acid levels, limiting its use. | Jams, jellies, fruit preserves, and confectionary fillings. | Specifically for traditional fruit preserves where sugar and acid are key components. |
Technical Documents
Available Documentation
COA, Technical Spec, MSDS available
Safety Data Sheet (SDS)
Provided
Certificate of Analysis (COA)
Quality assurance documentation
Technical Data Sheet
Detailed technical specifications