What is Dipotassium Phosphate (E340ii) in Food and Fertilizer?

Production | Property | Uses | Safety

Dipotassium Phosphate (abbreviation DKP), the soluble phosphoric acid salt of dipotassium with the chemical formula K2HPO4, also known as dipotassium hydrogen phosphate or potassium phosphate dibasic. 

This ingredient is vegan & gluten-free and can be used as a buffer, sequestrant and nutrient supplement in food with the European food additive number E340(ii)

Like monopotassium phosphate, it is also used to produce fertilizers, while tripotassium phosphate isn’t.

How is Dipotassium Phosphate made? 

DKP can be commercially synthesized by the controlled reaction of phosphoric acid with potassium hydroxide or potassium carbonate. The following are the chemical equations:

  • H3PO4+2KOH — K2HPO4+2H2O
  • K2CO3+H3PO4 — K2HPO4+H2O+CO2

Properties

Other names Dipotassium monophosphate; Secondary potassium phosphate; Dipotassium orthophosphate
Chemical formula K2HPO4
Molecular weight 174.18
CAS number 7778-77-0
Appearance White hygroscopic granular or powder
Solubility Freely soluble in water, insoluble in ethanol
PH 8.7 to 9.4 (1% solution)

DKP is a weak base, it dissociates PO43- and H+ after dissolved in water. At the same time, it reacts with water to form H2PO4- and OH- as the following chemical equation indicates:

  • HPO42- → PO43- + H+
  • H2PO4- + H2O → H3PO4 + OH-

What are the uses of Dipotassium Phosphate?

DKP is a highly water-soluble inorganic salt that can be used in a lot of applications, commonly as a food additive and fertilizer. 

Food

Dipotassium phosphate is commonly used as a buffering agent, mineral supplement, sequestrant, emulsifier, and a synergistic agent of antioxidation in food. It is a base so cannot be used as a leavening acid like monopotassium phosphate.

You may find this ingredient in the following food products:

  • Non-dairy creamers
  • Milk products
  • Mineral supplements
  • Powdered beverages
  • Cheeses
  • Meat
  • Low-sodium products 

Buffering agent 

DKP is a buffering agent or an acidity regulator to maintain solution PH to a specific value. DKP is added to reduce a rapid change in pH when acids or bases are added to the solution. 

DKP is used for this purpose to prevent coagulation in non-dairy creamer. In milk, it increases pH to assure milk protein stability and prevents precipitation.

Drink

DKP is a common source of phosphorus and potassium. In Coca Cola’s beverages, it is a source of potassium, which provides nutrition and also regulates blood pressure. (1)

Bodybuilding

Phosphorus plays an important role in the production of ATP (adenosine triphosphate), which produces energy for bodybuilders, weightlifters, and athletes during muscular performance. Meanwhile, potassium is an electrolyte which replenishes our body after sweating a lot.

DKP can be used as a nutrient supplement source of both phosphorus and potassium, and also as a buffering agent in energy drinks and a protein stabilizer in protein drinks. 

Fertilizer 

As a water-soluble phosphorus and potassium-based fertilizer in agricultural applications for growing plants.

Others 

DKP can also be used in the culture of microorganisms (e.g. fermentation processes of antibiotics and yeast ) as phosphorus is a component essential for microorganisms growth. 

Is Dipotassium Phosphate Safe to Eat?

Yes, DKP is safe and almost has no side effects when used as a food additive. It is generally considered as safe (GRAS) when used as as a sequestrant in accordance with good manufacturing practice by the FDA (2). 

Its safety has also been re-evaluated by the EFSA and an ADI (expressed as phosphorus) of 40 mg/kg body weight (bw) per day established in 2019. (3)

It has been authorized by JECFA since 1982 (4) with the function as an acidity regulator, sequestrant, yeast food. (5)

Conclusion

Now you may have a knowledge of the food additive – dipotassium phosphate E340(ii), from its production, properties, uses in food and fertilizer, approved safety and etc.

What kinds of products have you found this ingredient in? Let me know in the comments.

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