Reaction rate or gas-release curve
Ask what percentage of available carbon dioxide is released during the stated time, temperature and test system. Match it to mixing, depositing, bench, chilling/freezing and heating time.
Food grade leavening phosphate · E450(i) / INS 450(i)
Food Grade Sodium Acid Pyrophosphate (SAPP)
Source SAPP for controlled acid–bicarbonate leavening and selected potato color-control processes. Specify the reaction-rate grade, neutralizing value, particle profile and end use before approving a supply.
- CAS number
- 7758-16-9
- Formula
- Na2H2P2O7
- Reference assay
- ≥95.0%
- Reference MOQ
- 500 kg
Grade-defining inputReaction profile
Leavening calculationNeutralizing value
Reference packing25 kg bag
Batch qualificationCurrent COA on request
Product identity
What is sodium acid pyrophosphate?
Sodium acid pyrophosphate is the acidic disodium salt identified by JECFA as disodium dihydrogen diphosphate, INS 450(i). JECFA describes it as a white crystalline powder or granules, soluble in water, with raising-agent, buffering-agent and sequestrant functions.
In a chemical leavening system, SAPP supplies acid that reacts with sodium bicarbonate to release carbon dioxide. Commercial grades are not automatically interchangeable: their gas-release timing can change batter holding tolerance, oven lift, product geometry, crumb and finished pH.
The defining purchase decision
Select SAPP by reaction profile—not by name alone
Public technical literature describes commercial SAPP grades with different dough reaction rates. A grade number is meaningful only with its supplier's test method and specification; Bespring should not infer a SAPP 15, 28 or 40 designation unless the current product documents state it.
Neutralizing value (NV)
NV expresses the parts of sodium bicarbonate neutralized by 100 parts of leavening acid. Industry references place SAPP near 72, but the contracted grade value and calculation basis must come from the current specification.
Particle-size distribution
Granulation affects dry-blend uniformity, dissolution and reaction behavior. Compare mesh data and flowability when qualifying a replacement grade.
Finished-product validation
Measure batter or dough pH, gas retention, volume, shape, crumb, browning, taste and process tolerance in the customer's own formula.
Do not substitute on assay alone: two materials can both meet a ≥95% assay while producing different leavening behavior. Request reaction-rate, NV and particle-size data before a plant trial.
Application-specific validation
Where food grade SAPP is evaluated
Permission and maximum use depend on the destination market and food category. These pathways describe technical screening, not a universal use authorization or dosage.
Cakes, muffins and doughnuts
Balance early gas for batter expansion or fryer buoyancy with gas retained for heating. Check deposit time, volume, symmetry, crumb, oil uptake and aftertaste.
Biscuits, cookies and crackers
Reaction timing and finished pH can affect spread, lift, surface character and browning. Validate bicarbonate balance and particle distribution.
Baking powder and dry mixes
Review compatibility with bicarbonate and any second leavening acid, then protect the blend from moisture that could trigger premature reaction.
Refrigerated or frozen dough
Screen slower profiles where gas must be preserved through cold holding, thawing or delayed bake-off. Confirm stability in the full process rather than relying on a grade label.
A different SAPP buying intent
Processed potato color control
USDA's technical evaluation reports that SAPP is used as a sequestrant in processed potatoes to inhibit after-cooking darkening associated with iron–phenolic reactions. This is a different performance target from bakery leavening and should not be qualified with bakery reaction-rate data alone.
- Define the processFrench fries, flakes, granules, frozen or cooked potato products have different treatment points.
- Control the variablesRecord potato variety, iron in raw material/process water, blanching, treatment point, concentration, contact time and final pH.
- Measure the outcomeCompare after-cooking color, flavor, texture and phosphate-related limits against an untreated control and approved benchmark.
Commercial data with method boundaries
Food grade SAPP reference specification
The table reproduces Bespring's supplied commercial limits. It is not a batch COA or a claim of universal compliance. Obtain the signed specification, methods and current COA before approval.
| Test item | Unit | Supplied limit | Qualification note |
|---|---|---|---|
| SAPP assay | % | ≥95.0 | Confirm dry-basis method |
| Appearance | — | White powder | JECFA also permits crystalline granules |
| Water-insoluble matter | % | ≤1.0 | Method should match contract |
| Loss on drying | % | ≤0.5 | JECFA method: 105°C for 4 h |
| pH, 1% solution | — | 3.5–4.5 | Differs from JECFA 3.7–5.0 range |
| Fluoride (F) | mg/kg | ≤10 | Matches JECFA limit |
| Arsenic (As) | mg/kg | ≤3 | Matches JECFA limit |
| Lead (Pb) | mg/kg | ≤4 | Matches JECFA limit |
| Cadmium (Cd) | mg/kg | ≤1 | Supplied commercial parameter |
| Mercury (Hg) | mg/kg | ≤1 | Supplied commercial parameter |
| Heavy metals (as Pb) | mg/kg | ≤15 | Not the same test as lead (Pb) |
What JECFA independently supports
JECFA lists assay ≥95%, pH 3.7–5.0 for a 1-in-100 solution, loss on drying ≤0.5%, water-insoluble matter ≤1%, fluoride ≤10 mg/kg, arsenic ≤3 mg/kg and lead ≤4 mg/kg.
Open the JECFA specificationWhat the present sheet does not define
Reaction-rate grade, test curve, neutralizing value, P2O5, particle-size distribution, bulk density and shelf life are not stated in the supplied table. These must be confirmed rather than invented.
Replacement and approval workflow
How to qualify a SAPP supply
- 1
Lock the intended use
State the exact baked product, dry mix, cold-chain process or potato treatment and destination country.
- 2
Compare documents
Review the current specification, TDS, SDS, COA, test methods and only those certificates that apply to the quoted product and site.
- 3
Match the functional profile
For leavening, compare reaction curve, NV and mesh data. For potatoes, compare treatment conditions and color-control results.
- 4
Run a controlled trial
Use the approved benchmark and document process settings, finished pH, volume or color, sensory result and hold stability.
Packing, storage and logistics
Protect the reaction profile in storage
- Reference packing25 kg per bag; confirm liner, pallet and label requirements in the quotation.
- Moisture controlKeep bags sealed in a cool, dry and ventilated area; moisture can promote caking and premature reaction in leavening blends.
- TemperatureThe supplied guidance states no more than 30°C; follow the current SDS and storage document.
- Shipment planning24 MT per 20-foot container is a reference only; reconfirm palletization, weight limits and destination rules.
Buyer questions
Sodium acid pyrophosphate FAQ
What does the SAPP grade number mean?
Industry literature commonly relates the grade number to a measured reaction rate, but suppliers may state test conditions differently. Treat the number as incomplete unless the TDS defines the method, time, temperature and bicarbonate system.
Is SAPP the same as tetrasodium pyrophosphate?
No. SAPP is acidic disodium dihydrogen diphosphate, INS 450(i), with formula Na2H2P2O7. Tetrasodium pyrophosphate is an alkaline phosphate, INS 450(iii), with different chemistry and applications.
Can one SAPP grade replace another in baking?
Not on assay alone. Compare reaction rate, neutralizing value, particle size and finished-product performance. A plant trial should reproduce mixing, holding, temperature and bake or fry conditions.
Why is SAPP used in processed potatoes?
USDA technical literature describes its use as a sequestrant to limit iron-related after-cooking darkening. The treatment must be validated for the potato type, process, target market, color, flavor and texture.
What should be included in a SAPP RFQ?
Provide the application, required reaction-rate grade and method, NV, particle size, specification or benchmark COA, quantity, packing, destination, regulatory standard and required documents.
Substantive content review: 2026-08-22 · Independent identity and function references: FAO/WHO JECFA and USDA technical literature.
Specification-led sourcing
Request a food grade SAPP quote
For a comparable proposal, identify the functional grade—not only “SAPP food grade.”
- Application and production timing
- Reaction-rate method, NV and particle size
- Benchmark specification or COA
- Quantity, packing, destination and Incoterm