Sodium Tripolyphosphate (STPP) Food Grade

CAS Number:

7758-29-4

Chemical / IUPAC Name:

Pentasodium triphosphate

INCI Name:

Pentasodium Triphosphate (used in cosmetics); Sodium Tripolyphosphate (general)

EC Number:

231-838-7

Molecular Formula:

Na5P3O10

Molecular Weight:

367.86 g/mol

Other Names:

STPP, Sodium triphosphate, Sodium polyphosphate, E451(i)

Uses:

Food Grade Sodium Tripolyphosphate (STPP) is an inorganic salt and highly purified form of sodium triphosphate, appearing as a white, free-flowing powder or granules . It meets strict food safety standards (FCC, GRAS) and is widely used as a multifunctional food additive (E451i) .

· Meat, Poultry & Seafood Processing: Used as a moisture retention agent and water binder in processed meats, ham, sausages, and seafood. It increases the water-holding capacity of muscle proteins, reducing drip loss during thawing and cooking, resulting in juicier, plumper products with higher yield .

· Dairy & Processed Foods: Functions as an emulsifier and stabilizer in processed cheese, cheese spreads, and dairy products to prevent fat separation and ensure smooth melting .

· Canned Foods & Beverages: Acts as a quality improver in canned vegetables (softens bean skins), canned ham (tenderizes meat), and fruit juice drinks to maintain texture and stability .

· Seafood Preservation: Helps retain moisture in frozen shrimp, fish fillets, and other seafood during freezing and thawing, reducing weight loss and improving texture .

· Noodles & Pasta: Used to improve texture and reduce cooking loss in fresh and dried noodle products .

Origin

STPP is produced industrially by reacting thermal phosphoric acid (or highly purified wet phosphoric acid) with soda ash (sodium carbonate) . The resulting orthophosphate mixture is spray-dried or crystallized, then heated under carefully controlled conditions to permit polymerization into sodium tripolyphosphate .

What does STPP Food Grade do in a formulation?

• Moisture Retention Agent: Enhances water-binding capacity of proteins in meat and seafood, reducing moisture loss during processing, freezing, and cooking .
• Sequestrant / Chelating Agent: Binds multivalent metal ions (calcium, magnesium, iron, copper), preventing them from catalyzing oxidation reactions or forming insoluble precipitates .
• Emulsifier: Helps stabilize oil-in-water emulsions in processed cheese, sauces, and other food products .
• pH Buffer: Maintains optimal acidity in formulations; 1% aqueous solution has pH 9.5-10.0 .
• Texture Enhancer: Improves tenderness in meats and softens skins of legumes in canned products
• Antioxidant Synergist: Stabilizes iron and copper in their oxidized states, inhibiting lipid oxidation and rancidity in meat and emulsified systems .

Safety Profile:

· GRAS Status: Generally Recognized as Safe (GRAS) by the U.S. FDA for use in food when used in accordance with Good Manufacturing Practice (21 CFR 182.6810) . EU approved as food additive E451(i) .

· Concentration Limits: Usage levels vary by food category (typically 0.1-0.5%). Maximum permitted levels range from 900-5000 mg/kg depending on the specific food product (as phosphorus pentoxide or total phosphate) .

· Toxicity: Low acute toxicity. Acceptable Daily Intake (ADI) established by JECFA.

· Health Consideration: Excessive intake may contribute to elevated phosphorus levels in individuals with kidney disease; should be used within regulatory limits .

· Irritation & Sensitization: May cause mild eye or skin irritation upon direct contact with concentrated powder. Dust may irritate respiratory tract.

· Handling & Storage: Store in a cool, dry place in tightly sealed containers. Protect from moisture as it is hygroscopic. Keep away from acids .

· Regulatory Status: Meets FCC, Food Grade standards, and various pharmacopoeia specifications. Compliant with FDA, EFSA, and WHO food additive requirements .

Technical profile: