Food grade MKP E340(i)
- Food-additive identity and destination-market review
- Assay, pH, insolubles and elemental impurities
- Food-contact packing, traceability and applicable documents
- Performance in the actual food or fermentation system
Food grade acidic orthophosphate · E340(i) / INS 340(i)
Food Grade Monopotassium Phosphate (MKP)
Source food grade MKP for acidic phosphate buffering, controlled potassium and phosphorus input, and qualified fermentation or dry-food systems. Keep it separate from fertilizer-grade 0-52-34 MKP.
- CAS number
- 7778-77-0
- Formula
- KH2PO4
- 1% solution pH
- 4.2–4.7
- Reference MOQ
- 500 kg
Include the target pH, mineral basis, food standard, application, quantity and destination.
Reference assayKH2PO4 ≥98.0% on dry basis
Standard packing25 kg bag
Container loadingReference: 23 MT / 20' FCL
Food-grade reviewCOA and applicable certificates on request
Product identity
What is food grade monopotassium phosphate?
Monopotassium phosphate (MKP), also called potassium dihydrogen phosphate or monobasic potassium phosphate, is the acidic potassium orthophosphate KH2PO4. JECFA identifies it as INS 340(i), CAS 7778-77-0, with buffer, neutralizing-agent, sequestrant and yeast-food functions.
JECFA describes it as freely soluble in water with a pH of 4.2–4.7 for a 1% solution. It supplies potassium and phosphorus but does not provide sodium; any mineral or nutrition declaration must use the offered grade's certified composition and the complete finished-food formula.
The critical search and procurement boundary
Food grade MKP is not fertilizer MKP 0-52-34
The same chemical name and CAS appear in food and agricultural markets, but intended use, guaranteed analysis, impurity controls, manufacturing/packing scope and documentation are not interchangeable.
Fertilizer MKP 0-52-34
- N-P-K guaranteed analysis and crop application
- Water-soluble fertilizer and fertigation requirements
- Agricultural registration and contaminant rules
- Not approved for food merely because the formula is KH2PO4
Receiving control: require the label, lot number, signed specification and COA to identify the food-grade supply. Do not approve material using an agricultural NPK certificate.
Application-specific screening
Where food grade MKP is evaluated
These are technical evaluation paths, not universal permissions or dosage guidance. Confirm the food category, total phosphate, mineral declaration and destination-market rules.
Beverage and electrolyte dry mixes
Evaluate MKP when a soluble potassium/phosphate input and acidic buffer profile are required. Check reconstitution pH, mineral taste, clarity, sediment, compatibility with calcium/magnesium and declared nutrition.
Food fermentation and cultures
Use as a candidate phosphate/potassium source and buffer only after defining organism, medium composition and target pH. Track growth, acidification, yield, by-products and downstream purification.
Nutrition powders and premixes
Calculate potassium and phosphorus from certified composition, then test particle-size compatibility, blend segregation, dissolution, caking, sensory impact and label limits.
Acidic phosphate buffer systems
Pairing MKP with a more alkaline potassium phosphate such as DKP can broaden pH adjustment options. Determine the ratio experimentally in the real ionic and temperature environment.
Commercial data with method boundaries
Food grade MKP reference specification
The values reproduce Bespring's supplied product sheet. They are not a batch COA or evidence of universal compendial compliance. Confirm units, methods and the signed food-grade specification before approval.
| Test item | Unit | Supplied limit | Qualification note |
|---|---|---|---|
| KH2PO4 assay, dry basis | % | ≥98.0 | Matches JECFA minimum |
| Fluoride (F) | mg/kg | ≤10 | Matches JECFA maximum |
| Heavy metals (as Pb) | mg/kg | ≤10 | Not the same test as lead |
| “Loss on ignition” | % | ≤0.5 | Source method absent; JECFA specifies loss on drying, not LOI |
| Water-insoluble matter | % | ≤0.1 | Stricter than JECFA 0.2% |
| Arsenic (As) | mg/kg | ≤3 | Matches JECFA maximum |
| Cadmium (Cd) | mg/kg | ≤1 | Supplied commercial parameter |
| Mercury (Hg) | mg/kg | ≤1 | Supplied commercial parameter |
| Lead (Pb) | mg/kg | ≤5 | Does not meet JECFA 4 mg/kg maximum |
Specification decision: the supplied lead limit of 5 mg/kg is above JECFA's 4 mg/kg maximum. The sheet also omits pH, appearance, identity, solubility and a defined loss-on-drying method. Do not claim JECFA conformity without an offered grade and COA that meet the full standard.
JECFA reference
INS 340(i); assay ≥98% after drying; pH 4.2–4.7 (1%); loss on drying ≤2% at 105°C for 4 h; insolubles ≤0.2%; F ≤10, As ≤3 and Pb ≤4 mg/kg.
Review the JECFA MKP monographMissing purchasing fields
Request pH, potassium/phosphorus or K2O/P2O5 reporting basis where needed, solution clarity, chloride/sulfate/sodium, particle size, bulk density, moisture method and shelf life.
Choose the phosphate species
MKP vs. DKP and phosphoric acid
Selection begins with target pH and ion contribution, not with the shared word “potassium.” Equal-weight substitution changes potassium, phosphorus and acid/base balance.
MKP · KH2PO4
Acidic potassium orthophosphate
Use as a candidate where acidic phosphate buffering and potassium/phosphorus input are required. JECFA 1% pH: 4.2–4.7.
DKP · K2HPO4
More alkaline potassium orthophosphate
Compare when a higher pH response or different potassium-to-phosphate ratio is required. A controlled MKP/DKP ratio can be evaluated as a buffer pair.
Phosphoric acid · H3PO4
Acidulant without potassium input
Compare when acidification is the primary goal and added potassium is not desired. Handling, concentration and corrosion controls differ.
Theoretical composition for preliminary calculationsPure anhydrous KH2PO4 contains approximately 28.7% potassium and 22.8% phosphorus by mass. Use certified batch composition—not theoretical purity—for labels and commercial formulation.
Application approval
How to qualify food grade MKP
Connect the exact food-grade source to solution behavior, mineral balance, process response and destination-market rules.
- 1
Fix the target
State the food or fermentation process, target pH, potassium/phosphorus contribution, total phosphate and mandatory label or impurity limits.
- 2
Verify the grade
Match identity, food-grade standard, methods, traceability, current specification, TDS, SDS and COA. Review certificates only for the offered product/site and validity period.
- 3
Test solution behavior
Record water chemistry, temperature, concentration, ingredient order, dissolution time, clarity, sediment and measured pH.
- 4
Validate the end use
For beverages or powders assess taste, clarity and stability; for cultures assess growth, acidification, yield and downstream effects under matched conditions.
Storage and handling
Keep MKP cool, dry and sealed
- TemperatureThe supplied guidance states storage at no more than 30°C.
- EnvironmentProtect sealed bags from direct sunlight, high temperature, humidity and contamination in a ventilated area.
- Workplace controlsFollow the current SDS and site procedures for dust handling and personal protection.
Buyer questions
Food grade MKP FAQ
Is monopotassium phosphate the same as potassium dihydrogen phosphate?
Yes. Monopotassium phosphate, potassium dihydrogen phosphate and monobasic potassium phosphate identify KH2PO4. For food use, specify INS/E340(i), CAS 7778-77-0 and the required food standard.
How is food grade MKP different from fertilizer MKP 0-52-34?
They can share the same chemical formula, but fertilizer grade is controlled and labeled for plant nutrition. Food grade requires food-additive identity, appropriate impurities, traceability, packing and applicable food documents. An NPK certificate does not qualify a food ingredient.
Is MKP acidic or alkaline?
MKP is the acidic potassium orthophosphate. JECFA specifies pH 4.2–4.7 for a 1% solution. Actual formulation pH depends on concentration and the full buffer, mineral and acid system.
Does the supplied specification meet JECFA?
Not as written: the supplied lead limit is 5 mg/kg versus JECFA's 4 mg/kg maximum, and several JECFA identity/quality fields are absent. Request a source-specific grade and COA that meet the selected standard.
What details are needed for an MKP quotation?
State food grade, intended application, target pH, potassium/phosphorus or K2O/P2O5 basis, specification, particle/solution requirements, quantity, packing, destination, Incoterm and documents.
Substantive content review: 2026-08-22 · Independent identity and specification reference: FAO/WHO JECFA.
Related products and application guides
Continue the MKP selection
Dipotassium Phosphate
Compare a more alkaline potassium orthophosphate and potential MKP/DKP buffer pair.
Phosphoric Acid 85%
Compare phosphate acidification when potassium input is not required.
Beverage Formulation Solutions
Connect mineral and buffer selection with clarity, taste, pH and shelf-stability testing.
MKP Fertilizer Grade
Use the separate agricultural page for 0-52-34, fertigation and crop-nutrition intent.
Specification-led sourcing
Request a food grade MKP quote
Identify the food-grade standard and mineral basis so the response is not confused with fertilizer MKP.
- Food or fermentation application and target pH
- Potassium/phosphorus or K2O/P2O5 reporting basis
- Benchmark specification, particle and solution requirements
- Quantity, packing, destination, Incoterm and documents