Tetrasodium Pyrophosphate (TSPP) Explained: From Anhydrous to Decahydrate – A Multifunctional Ingredient in Food Formulations

In modern food processing systems, functional phosphates are no longer just “pH regulators” or “leavening agents.”

Tetrasodium Pyrophosphate (TSPP) is a true “master of structural stability”—thanks to its outstanding metal-chelating capacity, ion regulation properties, and emulsification synergy. It plays an indispensable role in dairy products, meat products, plant-based proteins, and powdered beverages.

So, what exactly is TSPP? How does it differ from its “sibling products” such as SAPP or STPP? And why is TSPP so frequently used in plant-based meats and high-calcium milk powders?

Let’s start with the most fundamental definitions and gradually uncover the secrets behind this type of functional phosphate.

I. Basic Understanding: What is Tetrasodium Pyrophosphate?

Tetrasodium Pyrophosphate (abbreviated as TSPP) is an inorganic phosphate-based food additive with the chemical formula Na₄P₂O₇. It is a type of pyrophosphate formed through the dehydration condensation of phosphate compounds.

In the food industry, TSPP is classified as a chelating agent, emulsifier, pH regulator, and structural stabilizer. On product labels, it typically appears as INS number 450(iii) or E450(iii). TSPP has good water solubility and strong metal ion chelation ability, making it a valuable tool in formulating stable food systems with desirable texture.

🔬 Key Parameters:

Item	Parameter & Description
Chemical Name	Tetrasodium Pyrophosphate
Chemical Formula	Na₄P₂O₇
CAS Number	Anhydrous: 7722-88-5; Decahydrate: 13472-36-1
Molecular Weight	Anhydrous: 265.90 g/mol; Decahydrate: 446.06 g/mol
Physical Form	White powder or granules; available as anhydrous or decahydrate
Solubility	Easily soluble in water; insoluble in alcohol
pH Level	Weakly alkaline; 1% solution pH approximately 9.5–10.5
Application Type	Chelating agent, emulsifying stabilizer, pH regulator, synergistic additive

II. Product Forms and Classification Standards: Key Differences Between Anhydrous and Decahydrate TSPP

Food-grade Tetrasodium Pyrophosphate (TSPP) is primarily available in two forms for practical applications: Anhydrous and Decahydrate. Although both share the same chemical formula, Na₄P₂O₇, their differing crystal water contents result in notable variations in physicochemical properties, usage conditions, application directions, and regulatory labeling.

These distinctions are critical when designing formulations and selecting raw materials.

🔬 Anhydrous vs. Decahydrate: Physicochemical Differences

Item	Anhydrous TSPP	Decahydrate TSPP
CAS Number	7722-88-5	13472-36-1
Molecular Formula	Na₄P₂O₇	Na₄P₂O₇·10H₂O
Molecular Weight	265.90	446.06
Appearance	White crystalline powder or fine granules	White to off-white crystalline powder
Crystal Water Content	0%	≈40%
pH (1% solution)	9.5–10.5	9.0–10.0
Water Solubility	Highly soluble, fast dissolution	Slightly slower dissolution, stable solution
Hygroscopicity	Low, convenient for storage and transport	Highly hygroscopic, requires sealed storage

🏭 Application Scenarios and Recommended Forms

Application Type	Recommended Form	Description
Dry Powder Systems (e.g., milk powder, coffee creamer, cereal blends)	Anhydrous	Low moisture content, excellent flowability, high stability
Liquid Systems (e.g., sauces, meat injection solutions, soy slurries)	Decahydrate	Easy dissolution, stable pH buffering, suitable for wet processing
Plant Protein Construction (e.g., plant-based milk, plant-based meat)	Decahydrate	Gentler protein interaction, helps build emulsified structures

📜 Regulatory Classification and Label Compliance

• China Standard: According to GB 1886.339-2021, hydration status must be indicated; food-grade purity ≥95%; heavy metals restricted (Pb ≤ 2 mg/kg, F ≤ 10 mg/kg);

• EU Regulations: Classified uniformly as E450(iii), hydration state not differentiated; dry basis purity ≥95%;

• U.S. FDA: Listed as a GRAS ingredient; broadly approved for use in bakery, meat products, seasonings, and dairy applications;

✅ Application Summary

The choice of form should depend on the actual product type and processing method:

• Dry systems: Prefer anhydrous type for long-term storage and rapid dispersion;

• Liquid systems: Recommend decahydrate type for its gentler dissolution, ideal for protein and emulsification systems;

III. Functional Properties: Chelation, Emulsification, and Stabilization Synergy

At this point, a natural question may arise: What makes Tetrasodium Pyrophosphate (TSPP) different from other phosphates?

The answer lies in its unique physicochemical characteristics, which allow it to do much more than regulate pH. Through powerful metal ion chelation, protein dispersion, and emulsification stabilization, TSPP becomes a key ingredient in enhancing the structure and quality of food systems.

Let’s explore its working principles in detail.

1️⃣ Chelating Metal Ions: Preventing Precipitation and Discoloration

The pyrophosphate group (P₂O₇⁴⁻) in TSPP exhibits excellent metal ion chelation capacity, particularly with Ca²⁺, Mg²⁺, and Fe³⁺:

• Prevents calcium salt precipitation: In high-calcium milk powders or soy milk, it helps avoid the formation of white calcium deposits.

• Inhibits iron-catalyzed browning: Effectively stabilizes the color in iron-containing systems like soy sauce, sauces, and seasoning powders.

• Maintains ionic balance: Prevents protein aggregation and destabilization of emulsified systems caused by metal ions.

📌 Application Tip: TSPP is especially crucial in hard water or dairy systems, helping maintain desirable color and texture.

2️⃣ Dispersing Proteins: Enhancing Emulsification and Water-Holding Capacity

TSPP can partially denature and disperse proteins by breaking calcium bridges and electrostatic interactions between protein molecules:

• Improves plant protein dispersibility: In plant-based milk, meat analogs, and soy products, it enhances emulsion smoothness and textural uniformity.

• Boosts emulsion stability in meat products: In items like sausages, chicken nuggets, and surimi, it improves fat encapsulation and thermal stability.

• Enhances water retention: In frozen meats and dairy alternatives, it reduces syneresis and minimizes ice crystal formation.

📌 Example: TSPP is often used in combination with STPP (Sodium Tripolyphosphate) to improve water retention and elastic structure.

3️⃣ Stabilizing System pH: Enhancing Compatibility

As a mildly alkaline buffering salt, TSPP provides effective pH regulation within the 8.5–10 range:

• Regulates protein system pH: Improves protein solubility and overall emulsification performance.

• Stabilizes flavors and nutrients: Maintains taste and nutrient integrity in milk powders, nutrition powders, and seasonings.

• Prevents pigment and vitamin degradation: Especially important during high-temperature spray drying and long-term storage.

📌 Supplementary Note: When combined with sodium citrate or disodium phosphate, it forms a complete dual-salt buffering system.

IV. Application Fields: From Food Structure Optimization to Stabilizers in Personal Care Products

With the above mechanisms in mind, it becomes clear that Tetrasodium Pyrophosphate (TSPP), thanks to its excellent chelation ability, emulsification stability, and pH-regulating properties, serves as a multifunctional inorganic phosphate.

It is widely used across a variety of food systems, particularly in plant-based protein processing, milk powders and non-dairy beverages, meat products, and functional nutritional powders, where it plays an irreplaceable role in structure enhancement.

1️⃣ Plant-Based Beverages and Meat Alternatives: The “Structural Backbone” for Emulsification and Texture Stability

In plant-based milks (e.g., soy milk, oat milk) and plant-based meats (e.g., soy protein products, meat analogs), TSPP plays a key role in protein dispersion and system stability:

• Improves protein suspension and rheology: Prevents sedimentation, flocculation, and phase separation;

• Enhances the texture of meat analogs: Improves elasticity and chewiness;

• Maintains emulsion stability in low pH environments: Increases the durability of acidic fruit-flavored plant-based beverages.

📌 Recommended Combination: Use with STPP or disodium phosphate to enhance protein interfacial activity and pH buffering capacity.

2️⃣ Milk Powders, Seasoning Powders, and Functional Powder Systems: The Guardian of Dispersion and Storage Stability

In high-calcium milk powder, instant milk tea powder, and protein meal replacement powders, TSPP acts as a critical ionic stabilizer and dispersion aid:

• Prevents Ca²⁺ precipitation: Enhances reconstitution and liquid clarity;

• Improves heat stability during spray drying: Prevents caking and flavor degradation;

• Controls pH: Protects the structure of ingredients like whey protein and non-dairy creamers.

📌 Special Note: Use decahydrate TSPP for better dispersibility and dissolution performance.

3️⃣ Meat and Seafood Products: A Synergistic “Seasoning Agent” for Water Retention and Elasticity

In products like ham, chicken breast, fish balls, and crab sticks, TSPP is often part of a compound phosphate mix that helps improve water retention, texture, and flavor uniformity:

• Chelates Ca²⁺/Mg²⁺ to disrupt actomyosin bridges: Enhances water-holding in muscle tissues;

• Works synergistically with NaCl to extract myofibrillar proteins: Promotes protein gel network formation;

• Maintains pH stability: Prevents protein aggregation and water loss during heating.

📌 Application Tip: TSPP typically accounts for 10–30% of total phosphate blends; use with STPP and sodium tripolyphosphate for optimal performance.

4️⃣ Functional Nutritional Supplements and Medical Foods: Regulating Ion Balance and Enhancing Nutrient Stability

In calcium-, iron-, and zinc-fortified beverages, senior nutrition powders, and specialized medical nutrition products, TSPP protects nutrient structure by adjusting pH and ionic concentration:

• Prevents trace element precipitation/inactivation: Enhances calcium and iron bioavailability;

• Inhibits vitamin oxidation/degradation: Extends shelf life;

• Improves texture and mouthfeel: Makes formulas smoother and easier to swallow.

📌 Compliance Tip: Heavy metals must be strictly controlled; only food-grade certified anhydrous TSPP should be used.

In addition, due to its outstanding chelating capacity, pH buffering properties, and structural synergy, TSPP is not only widely used in the food industry but also plays a key role in personal care products and toothpaste formulations.

When added to toothpaste, TSPP forms stable complexes with calcium ions, preventing calcium salt precipitation. It also helps reduce tartar buildup and improves product stability and appearance, making it a common ingredient in fluoride-containing and anti-tartar toothpastes. It complies with regulations in the EU, U.S., Japan, and other countries.

🧠 Application Summary:

Application Scenario	Recommended TSPP Form	Functional Objective	Synergistic Recommendation
Plant-based milk, soy foods	Decahydrate TSPP	Protein stabilization, uniform emulsification	Combine with STPP, sodium citrate
Milk powders, milk tea powders	Anhydrous TSPP	Fast dissolution, anti-caking	Combine with disodium phosphate
Ham, surimi products	Anhydrous/Decahydrate TSPP	Water retention, elasticity, preservation synergy	Combine with sodium tripolyphosphate
Medical foods, supplements	Anhydrous TSPP	Trace element regulation, nutrient stabilization	Combine with whey protein, vitamins

V. Regulatory Standards and Safety Compliance: A Globally Recognized Food Additive 📜

Tetrasodium Pyrophosphate (TSPP), as an important multifunctional food phosphate, has been approved by food safety regulations in most countries and regions around the world. It is widely used in dairy products, meat products, and plant-based foods. Below is a summary of major regulatory standards and key considerations:

🌍 Regulatory Framework and Usage Requirements in Major Regions:

Country/Region	Regulatory Reference & Classification	Permitted Uses	Usage Limits	Special Notes
🇨🇳 China	GB 1886.339-2021	Milk powder, surimi, noodles, non-dairy creamers	Proper use under QS standard; some foods ≤5g/kg	Food-grade decahydrate or anhydrous only; Pb ≤ 2 mg/kg
🇪🇺 EU	E450(iii), Regulation EC 1333/2008	Dairy, ready-to-eat foods, plant protein products	Total phosphate ADI: 70 mg/kg body weight	Can be used with other phosphates, but total phosphate intake is regulated
🇺🇸 USA	21 CFR 182.1089; GRAS (Generally Recognized As Safe)	Meats, infant formula, compound seasonings	No specific limit, but must follow labeling and GRAS rules	Emphasis on absence of lead/heavy metal contamination
🌐 CODEX/International	INS 450(iii)	Widely used in compound phosphates, fortified powders	General max ≤10g/kg (depending on formulation)	Eligible for HALAL, KOSHER certification

📌 Usage Guidelines and Compliance Tips:

1. Form Specification:

   
   

   • Decahydrate TSPP: Suitable for systems requiring high solubility and flowability, such as liquids or powders;

   
   

   • Anhydrous TSPP: Suitable for high-temperature/high-pressure applications, such as cooked meat products and protein gel systems;

   
   

   • Both forms must indicate batch number, grade, and compliance with food additive standards.

   
   

2. Heavy Metal Control:

   
   

   • Strict limits on impurities such as lead (Pb), arsenic (As), cadmium (Cd), etc.

     
     

✅ Safety Assessment:

According to studies by the FAO/WHO Joint Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA), TSPP is classified as a low-toxicity, stable multifunctional additive. When used within approved limits, it poses no toxicological risk. Key safety notes include:

• Control total phosphate intake, especially for populations on long-term high-phosphorus diets (e.g., kidney disease patients);

• Avoid direct combination with strong acids to prevent phosphate precipitation or premature CO₂ release in formulations;

• Distinguish product grades: Industrial-grade products must not be substituted for food-grade materials.

VI. Market Landscape and Future Trends

As a multifunctional phosphate, food-grade Tetrasodium Pyrophosphate (TSPP) has long been widely used in the global food industry. With rising demands for healthier food, multifunctional ingredient systems, and increasingly refined regulatory frameworks in international markets, TSPP is now undergoing a dual transformation: industrial structural upgrade and the expansion of new application needs.

🌍 Overview of the Global Market Landscape

Region	Key Applications	Industry Trends & Challenges
🇨🇳 China	Surimi products, milk powder, plant-based foods	One of the largest producers and exporters; product structure upgrading toward lead-free and high-purity forms; supports customized granules and blends
🇪🇺 European Union	Cheese alternatives, ready-to-eat meals	High regulatory compliance and transparent labeling required; exploring algae-based natural substitutes; TSPP remains a core additive in plant-based meats
🇺🇸 North America	Frozen meats, seasoning powders, protein powders	Emphasis on GRAS certification, lead- and arsenic-free; preference for imported products with KOSHER/HALAL certification
🇸🇦 Middle East	Chilled meat, economical milk powders	Focus on water retention and price sensitivity; reliant on imports; HALAL certification is key for market entry
🇮🇳 South Asia & 🇻🇳 Southeast Asia	Culinary seasonings, instant powders, budget milk powders	Rapid growth but inconsistent standards; priorities include shelf life, flowability, and compatibility with local staple systems

📌 Closing Remark:Though not a new additive, TSPP is experiencing renewed vitality in the context of functional foods and globalization—thanks to its stability, compatibility, and cost-effectiveness.

✅ Final Note: Unlocking the Versatile Potential of TSPP Through Scientific Use

The enduring presence of Tetrasodium Pyrophosphate (TSPP) in the food industry stems from its comprehensive advantages in structure optimization, quality control, and thermal stability. Whether it's used for dispersion control in seasoning powders or texture enhancement in surimi, milk powders, and plant proteins, TSPP consistently contributes to improved product quality and manufacturing efficiency due to its stable, efficient, and easy-to-apply characteristics.

However, it's equally important to recognize: TSPP is not a “more-is-better” ingredient, nor is it suitable for every food formulation. Sustainable application in future markets will rely on scientific selection, rational formulation, regulatory compliance, and quality traceability, including:

🔎 Identify the product form: Distinguish between anhydrous and decahydrate types to match dissolution speed and processing temperature;

📦 Confirm usage grade: Ensure only food-grade TSPP is used; industrial-grade products must be strictly excluded from food systems;

📄 Comply with usage limits: Formulations should adhere to relevant standards such as China GB, EU EC 1333, U.S. FDA, or CODEX;

🧪 Prioritize quality control: Monitor heavy metal limits (e.g., lead, arsenic, cadmium), and maintain low impurity purity standards.

🏁 Final Message from Kelewell

As a functional phosphate supplier, Kelewell is committed to providing global food manufacturers with stable and reliable TSPP products and solutions. We support customers with customized packaging, regulatory assistance, functional testing, and sample provision—empowering efficient formulation development and export expansion.

📩 If you have any technical questions or project needs regarding TSPP or other phosphate products, feel free to contact our team at any time.

—Kelewell, advancing every step of food innovation with you.