Disodium pyrophosphate

Disodium pyrophosphate (CAS 7758-16-9), also known as SAPP and sodium acid pyrophosphate, is an inorganic phosphate salt used in food manufacturing and water treatment as a buffering, leavening, and sequestering agent. E450a.

Where is Disodium pyrophosphate used?

• Baked goods: leavening acid in baking powder and self-rising flour
• Baking: reacts with sodium bicarbonate for controlled CO₂ release
• Provides a buffer system for dough in the pH range 7.3–7.5, which influences the color of the baked product.
• Potato processing: inhibits after-cooking darkening by chelating iron and trace metals
• Seafood and meat processing: moisture stabilizer and texture modifier that reduces drip loss in frozen products
• Dairy-based products and processed cheese: serves as an emulsification aid.
• Water treatment: sequesters hardness ions and controls scale formation
• Water treatment: acts as a corrosion inhibitor and sequestrant to prevent scale and metal deposits in pipelines.
• It controls pH, binds metal ions, and stabilizes formulations where precise acidity management is critical.

Good to know: Buyers should confirm the slow-acting or fast-acting leavening profile when sourcing, as reaction rate varies by grade. Select the correct version for specific baking applications.

Typical specification

• Solubility in water is 13 g Na2H2P2O7 per 100 g H2O at 20°C and 20 g at 80°C.
• Neutralizing value (NV) is 70.
• Purity of 92.0–101.0% is available.
• FCC and food-grade specifications are available for food applications and technical grade for water treatment.

Regulatory status

• E number E 450i applies in the EU.
• INS number 450i applies.

Frequently asked questions about Disodium pyrophosphate

How does the reaction rate of disodium pyrophosphate vary between grades for baking applications?

Disodium pyrophosphate is a slow-acting acid, and grades can contain a suitable aluminum and/or calcium salt to control the reaction rate.

What is the role of disodium pyrophosphate in cured meat processing?

It accelerates the conversion of sodium nitrite to nitrite in cured meats and can increase water-holding capacity.

What is the effect of humidity on the physical form of disodium pyrophosphate?

It is hygroscopic and forms a hexahydrate in humid air.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.