Sodium Citrate, Trisodium Citrate Anhydrous, Trisodium Citrate Anhydrous Dihydrate, Lemon Salt, E331, 68-04-2, 6132-04-3

Sodium Citrate, Trisodium Citrate Anhydrous, Trisodium Citrate Anhydrous Dihydrate, Lemon Salt, E331, 68-04-2, 6132-04-3

General Information

• Chemical Name: Trisodium Citrate (Anhydrous / Dihydrate)

• Molecular Formula: Na₃C₆H₅O₇·nH₂O

• Molecular Weight: 258.06 g/mol (Anhydrous) / 294.10 g/mol (Dihydrate)

• CAS Numbers: 68-04-2 (Anhydrous) / 6132-04-3 (Dihydrate)

• Food Additive Code: E331

• Appearance: White, odorless crystalline solid with a slightly salty, cooling taste

• Density: 1.76 g/cm³

• Solubility: Highly soluble in water (solubility increases with temperature); almost insoluble in ethanol

• pH: 5% aqueous solution has pH ≈ 8.5

• Stability: Stable compound; decomposes above 150 °C by losing water. Incompatible with strong bases, oxidizing and reducing agents.

Chemical & Functional Properties

• Tribasic salt of citric acid (three sodium ions replace three acidic protons).

• Buffering capacity: Widely used for pH adjustment.

• Chelating ability: Forms complexes with Ca²⁺, Mg²⁺, Fe²⁺ ions.

• Emulsifying agent: Helps stabilize fat-water mixtures.

• Moisture control: Prevents caking in powders, extends shelf life.

• Low reactivity: Non-toxic, chemically stable.

Applications

1. Food Industry

• Acid regulator, emulsifier, preservative.

• Used in cheese (especially processed sliced cheese with dihydrate form), jams, jellies, ice cream, confectionery.

• Enhances tart flavor in beverages, soft drinks, and wine.

• Prevents enzymatic browning in potatoes and fruits.

• Controls water activity in baked goods.

• Active ingredient in baby formula production.

2. Pharmaceutical & Medical

• Anticoagulant: Prevents blood clotting in transfusions.

• Buffering agent: Stabilizes drug formulations.

• Alkalinizing agent: Neutralizes excess acid in blood and urine; used in metabolic acidosis treatment.

• Excipient: Incorporated in diuretics, expectorants, and oral drops for stomach pain.

• Cosmetic & pharma formulations: Improves stability and preservative efficiency.

3. Industrial

• Detergents: Alternative to phosphates in eco-friendly formulations; enhances cleaning power.

• Electroplating: Used in cyanide-free plating baths.

• Antifreeze: Stabilizes glycol solutions against thermal degradation.

• Cleaning agents: Strengthens magnesium-based cleaning formulations.

• Carrier material: Anhydrous form is porous (~15%), useful for absorbing liquids.

Synonyms & Alternative Names

• Sodium Citrate

• Citric Acid Trisodium Salt

• Trisodium Citrate Anhydrous / Dihydrate

• Melting Salt

• Lemon Salt

• Sitrat (Turkish)

Summary Table