Dipotassium Hydrogen Phosphate Trihydrate (K₂HPO₄·3H₂O) Applications

What Is Dipotassium Hydrogen Phosphate Trihydrate?

Dipotassium hydrogen phosphate trihydrate (CAS 16788-57-1), also known as dipotassium phosphate trihydrate, DKP trihydrate, or E340(ii) in food-grade nomenclature, is an inorganic phosphate salt with the molecular formula K₂HPO₄·3H₂O and a molecular weight of 228.22 g/mol. It appears as white or colorless crystalline granules or powder, is freely soluble in water (pH 8.5–9.6 in 1% aqueous solution), and is insoluble in ethanol.

As the trihydrate form of dipotassium phosphate, it contains three molecules of crystallization water. When heated, it loses water of crystallization and converts to the anhydrous form (K₂HPO₄, CAS 7758-11-4). This compound is one of the most versatile potassium phosphates, serving as a buffering agent, emulsifier, nutrient source, sequestrant, and stabilizer across multiple industries — from food processing and agriculture to industrial fermentation and water treatment.

Chemical & Physical Properties

Key Applications of Dipotassium Hydrogen Phosphate Trihydrate

1. Food Industry (E340ii)

As a food additive (E340ii / INS 340ii), dipotassium phosphate trihydrate is recognized as safe by the FDA, EFSA, and JECFA. Its primary functions in food processing include:

Buffering Agent & pH Regulator

● : Maintains optimal pH in processed cheese, sauces, and dairy products, preventing undesirable pH shifts during processing and storage.

Emulsifier & Stabilizer

● : Enhances texture and prevents separation in non-dairy creamers, imitation dairy products, evaporated milk, and powdered beverage mixes.

Sequestrant

● : Binds metal ions that can cause discoloration, rancidity, or turbidity, improving product shelf life and appearance.

Nutrient Supplement

● : Provides a source of potassium and phosphorus for mineral-fortified foods and sports nutrition products.

Fermentation Agent

● : Used in the preparation of alkaline water for noodle and pasta products; serves as a leavening agent and dough conditioner in bakery formulations.

Yeast Nutrient

● : Supplies phosphorus, an essential element for yeast metabolism, in brewing and baking processes.

2. Agriculture & Fertilizers

In agriculture, DKP trihydrate is valued as a high-purity, water-soluble source of both potassium (K) and phosphorus (P) — two of the three primary macronutrients plants require.

Water-Soluble Fertilizer: With an NPK-equivalent analysis of approximately, Haifa DKP™ and similar products are widely used in hydroponics, fertigation systems, and foliar spray applications. The high P and K content promotes root development, flowering, fruiting, and overall stress tolerance.

Greenhouse & Controlled-Environment Agriculture: Its complete water solubility and chloride-free, sodium-free profile make it ideal for precision nutrient management in protected cultivation.

Alkaline Soil Reaction: Unlike many phosphorus fertilizers that acidify the rhizosphere, DKP contributes a mildly alkaline reaction in the soil, beneficial for crops in acidic soil conditions.

Compound Fertilizer Production: Used as a raw material to produce NPK blends and specialty fertilizers tailored to specific crop requirements.

3. Industrial Fermentation & Biotechnology

Dipotassium hydrogen phosphate trihydrate is a core ingredient in microbial culture media and industrial fermentation processes:

Buffer Component

● : Maintains stable pH in bacterial, yeast, and fungal fermentation broths — critical for consistent metabolite production (enzymes, organic acids, amino acids, antibiotics).

Phosphorus & Potassium Source

● : Supplies essential macroelements for microbial growth in production-scale fermenters. For example, in lactic acid bacteria (LAB) fermentation, K₂HPO₄ serves both as a nutrient and as a pH buffer.

Culture Media Preparation

● : A standard component in laboratory media formulations (e.g., LB broth, M9 minimal medium, PBS buffer) for microbiological research and quality control testing.

Enzyme Production

● : Used in the cultivation of microorganisms engineered for industrial enzyme production.

Conclusion

Dipotassium hydrogen phosphate trihydrate (K₂HPO₄·3H₂O, CAS 16788-57-1) is an indispensable multi-functional phosphate compound serving the food industry as an emulsifier and stabilizer (E340ii), agriculture as a premium water-soluble PK fertilizer, biotechnology as a fermentation nutrient and buffer, and industrial sectors as a corrosion inhibitor and water treatment agent.