From Tender Canned Meat to Industrial Cleanliness: Unveiling the “Alkalinity Control Master” — Trisodium Phosphate (TSP)

Have you ever wondered why the meat in canned products remains so tender and juicy? Why dairy processing equipment stays clean and shiny over time? Or why the texture of plant-based meat is getting closer and closer to that of real meat? The answer often lies in a quiet yet powerful helper behind the scenes — Trisodium Phosphate (TSP).

TSP is a multifunctional and precisely effective inorganic salt, widely used in food processing, industrial cleaning, water treatment, and even structural enhancement of plant-based foods. Thanks to its strong alkalinity, excellent metal ion chelating ability, and high thermal stability, TSP plays a critical role in many formulations. In food science, it acts as both a texture regulator and a pH engineer, not only enhancing taste and mouthfeel but also influencing protein structure and the stability of complex food systems on a microscopic level.

Today, we take a more technical look to fully explore this “alkalinity control master” — its physicochemical properties, application logic, and regulatory boundaries — helping you understand how it protects food quality and industrial performance from the inside out.

I. Basic Understanding: What Is Trisodium Phosphate (TSP)?

Trisodium Phosphate (TSP, Na₃PO₄) is an inorganic phosphate salt formed by the neutralization of phosphoric acid (H₃PO₄) with sodium hydroxide (NaOH). At room temperature, it appears as a white crystalline or powdered solid. TSP is characterized by its strong alkalinity (pH of 1% aqueous solution approximately 11.5–12) and excellent metal ion chelating ability, especially effective at binding calcium and magnesium ions commonly found in hard water. This makes it a stable and versatile agent in both food and industrial applications.

TSP is commonly found in two forms:

• Anhydrous form (Na₃PO₄): Highly hygroscopic, suitable for applications requiring fast dissolution and high reactivity.

• Dodecahydrate (Na₃PO₄·12H₂O): More stable crystalline form, commonly used in food additives and cleaning agents.

In international regulatory frameworks, food-grade TSP is classified as a phosphate food additive (EU designation: E339 (iii)). It is widely applied in meat processing, seafood preservation, dairy formulations, and bakery products to enhance structure, improve water retention, and regulate pH. In industrial settings, TSP serves as an effective water softener, descaling agent, and metal surface cleaner — a testament to its identity as a true “alkalinity multitasker.”

Thanks to its high chemical stability, controllable reactivity, and lack of organic toxicity residues, Trisodium Phosphate has become a preferred raw material in both food formulation engineering and industrial cleaning technologies, offering an ideal balance of performance and cost-effectiveness.

II. Physicochemical Properties: What Are TSP’s “Innate Talents”?

Trisodium Phosphate stands out in a wide range of applications thanks to its excellent physicochemical properties. These “inherent traits” enable it to perform reliably in demanding industrial processes while also allowing for precise control in food formulations. Below is a comparison of the key parameters of the two most common forms of TSP:

Property	Anhydrous Trisodium Phosphate (Na₃PO₄)	Trisodium Phosphate Dodecahydrate (Na₃PO₄·12H₂O)
CAS Number	7601-54-9	10101-89-0
Appearance	White powder, highly hygroscopic, prone to clumping	White crystalline granules, more stable, tends to effloresce
Molecular Weight	163.94 g/mol	380.12 g/mol
pH (1% solution)	11.5–12.0 (strongly alkaline)	11.5–12.0 (strongly alkaline)
Solubility in Water (20°C)	14.5 g/100 mL (dissolves quickly, exothermic)	8.8 g/100 mL (dissolves slowly, releases crystal water)
Melting Point	Approx. 1340°C (thermally stable, non-decomposing)	73.4°C (melts and loses crystal water, forms anhydrous form)
Chelating Ability	Very strong, effectively binds Ca²⁺, Mg²⁺ ions	Comparable to the anhydrous form
Storage Requirements	Store sealed, protected from light and moisture	Store in a dry, well-ventilated place to avoid efflorescence and crystal water loss

Summary:

• Anhydrous TSP is ideal for applications requiring fast reactivity or zero water interference. In food applications, it’s preferred where moisture control is critical.

• TSP dodecahydrate is better suited for controlled-release and moderate alkalinity adjustment in food processing, but care must be taken when using it in formulations sensitive to moisture, due to its crystal water content.

Additionally, TSP releases heat upon dissolution, forming a strongly alkaline solution rapidly. It remains chemically stable under high temperatures (≤200°C), making it suitable for heat-intensive applications such as cooking, baking, and sterilization.

III. Production Process: The “Standardized Path” from Raw Materials to Final Product

Trisodium phosphate is primarily produced via the neutralization method, a well-established, safe, and efficient industrial process. While the reaction pathway is largely the same for both food-grade and industrial-grade products, the production of food-grade TSP involves significantly stricter controls in terms of purity, impurity removal, and sanitary conditions. The overall process consists of four key stages:

1. Raw Material Selection and Pretreatment

High-purity phosphoric acid (H₃PO₄, food-grade purity ≥98%) and sodium hydroxide (NaOH) are used as the base raw materials. Prior to reaction, these inputs undergo heavy metal removal, filtration, and ion exchange steps to ensure that the final product meets food safety standards.

Particular attention is paid to the control of toxic heavy metals such as lead (Pb), arsenic (As), and cadmium (Cd), which is one of the most critical requirements in food-grade production.

2. Neutralization Reaction (Main Reaction Stage)

In a sealed, stirred reactor, phosphoric acid is slowly added dropwise to the sodium hydroxide solution while maintaining the reaction temperature at 80–90°C. The pH of the system is continuously monitored and adjusted to fall within 11.5–12.0.

This is a typical acid-base neutralization reaction:

H3PO4+3NaOH→Na3PO4+3H2O

The resulting trisodium phosphate solution is clear and transparent, setting the foundation for the crystallization stage that follows.

3. Crystallization and Drying

After neutralization, the solution is concentrated and cooled to induce crystallization of the dodecahydrate form (Na₃PO₄·12H₂O). Further heating to 100–120°C, with careful control of time and temperature, allows for the removal of crystal water and the formation of anhydrous TSP (Na₃PO₄).

Various drying methods — such as vacuum drying or hot air drying — are selected based on the target grade and performance requirements.

4. Refining and Product Grading

Food-grade TSP must undergo further purification via secondary crystallization, membrane separation, or ion exchange to ensure it meets the safety limits outlined in GB 1886.25-2016:

• Lead (Pb) ≤ 2 mg/kg

• Arsenic (As) ≤ 3 mg/kg

At the same time, it must maintain good sensory and physicochemical characteristics (e.g., color, particle size, clarity, and chemical stability).

In contrast, industrial-grade products place greater emphasis on yield and chelating efficiency, rather than ingestion safety, and may tolerate slightly higher levels of residual impurities.

IV. Core Applications: Where Does TSP “Shine”?

Thanks to its strong alkalinity, metal ion chelating capacity, and high thermal stability, Trisodium Phosphate (TSP) is widely used across food, industrial, cleaning, and water treatment sectors. It has become a go-to “functional solution” in many critical processes. Below is a categorized overview of its typical applications:

(1) Food Industry (Food-Grade TSP)

Food-grade TSP is classified as a phosphate food additive under the EU designation E339(iii) and is also listed in China’s national food additive standard GB 2760–2024. Its core functionalities in food processing can be summarized as follows:

Application Scenario	Functional Mechanism	Practical Benefit
Meat, poultry, and seafood processing	Chelates Ca²⁺/Mg²⁺ and interferes with actomyosin cross-linking	Enhances water retention, reduces cooking loss, improves tenderness
Frozen fish balls, imitation crab sticks, canned meats	Alkaline action promotes protein unfolding and gel formation	Maintains elastic texture and chewiness
Baked dough (e.g., bread, cakes)	Adjusts pH and strengthens gluten network	Produces fluffier dough with better structure
Non-dairy creamers, recombined milk powder, plant-based beverages	Buffers pH and inhibits calcium salt precipitation	Improves emulsion stability, prevents lumping and sandy texture
Equipment cleaning (CIP systems)	Strong alkalinity + chelation of Ca²⁺/Mg²⁺, dissolves protein and milk residues	Effectively removes buildup, enhances hygiene in food production lines

📌 Additional Note:In plant-based food systems, TSP is increasingly used to improve legume protein structure, reduce sedimentation, and enhance moisture retention. It has become an important structural modifier in plant-based milk and meat alternatives.

(2) Industrial Applications (Industrial-Grade TSP)

Application Scenario	Functional Mechanism	Practical Benefit
Boiler and pipeline water treatment	Chelates Ca²⁺/Mg²⁺ in water	Softens hard water, prevents scaling, improves heat exchange efficiency
Laundry detergents, heavy-duty kitchen degreasers	Strong alkalinity + chelation + emulsification of oils	Enhances cleaning performance, especially on mineral and protein-based stains
Metal surface treatment (pre-electroplating)	Alkaline cleaning + oxide layer removal	Improves coating adhesion, prevents flaking and spotting
Pigment dispersion and ceramic additives	Binds metal ions and adjusts system pH	Stabilizes slurry, improves dispersion (widely used in ceramic glaze formulations)

🧭 Summary:

• Food-grade TSP serves as a precision additive for structural and functional modulation in food systems.

• Industrial-grade TSP acts as a performance-enhancing base material for cleaning, dispersion, and system stability.

Although they are chemically identical, the usage logic and regulatory requirements for food-grade and industrial-grade TSP differ significantly and must be strictly distinguished.

V. Functional Mechanisms: Why Is TSP So Versatile?

Trisodium Phosphate stands out in a wide range of applications because it possesses three core chemical functionalities, enabling it to perform reliably and effectively in diverse scenarios such as food texture control, cleaning and descaling, and water stabilization. Below is a breakdown of its key “functional strengths”:

🧪 Property 1: Strong Alkalinity — “The pH Adjustment Specialist”

TSP is a typical alkaline salt. In aqueous solution, phosphate ions (PO₄³⁻) undergo hydrolysis to release hydroxide ions (OH⁻), rapidly raising the pH of the system to approximately 11.5–12.0. This high alkalinity underpins the following functions:

• pH Adjustment in Food Systems: Shifts mildly acidic environments to weakly alkaline, improving protein solubility and structural stability;

• Fat Breakdown and Emulsification: In high-pH conditions, fats undergo saponification and emulsification, significantly enhancing the degreasing power of cleaning agents;

• Antibacterial and Preservative Effects: Most bacteria cannot survive in environments with pH >10; TSP helps extend shelf life, especially in heat-treated products like canned and chilled items;

• Formulation Buffering: When combined with sodium citrate or other buffering agents, it helps stabilize formulations against fluctuations in acidity from raw materials.

🧪 Property 2: High Chelating Capacity — “The Metal Ion Catcher”

TSP is an excellent metal chelating agent. Phosphate ions (PO₄³⁻) readily bind with calcium (Ca²⁺), magnesium (Mg²⁺), and other free or hard water ions in solution to form soluble complexes or precipitates, delivering the following effects:

• Water Softening: Prevents Ca²⁺ from reacting with SO₄²⁻ or CO₃²⁻ to form scale, keeping piping and reaction systems clean and efficient;

• Protein Structure Modification: By chelating calcium and magnesium, TSP loosens the tertiary structure of proteins, enhancing water-binding capacity and improving texture and mouthfeel;

• Minimizing Inorganic Salt Precipitation: Helps suppress the formation of calcium and magnesium phosphate precipitates in formulations such as milk powder, dairy beverages, and creamers — improving product stability and shelf life.

🧪 Property 3: High Thermal Stability — “Heat-Processing Friendly”

TSP remains chemically stable at typical food processing temperatures (< 200°C), meaning it neither decomposes into harmful by-products nor loses functionality when heated. This makes it ideal for:

• Canned products requiring high-temperature sterilization (121°C for 30 minutes);

• Baked goods such as bread and biscuits (180–220°C);

• High-temperature processing of plant proteins and spray-drying of recombined milk powders.

In short: TSP can serve as a stable functional additive throughout the entire production cycle — from raw material preparation to heat processing and even storage of the finished product.

📌 Summary:

Trisodium Phosphate is far more than just another phosphate salt — it is a multi-functional regulator that integrates pH adjustment, metal ion chelation, and thermal stability, making it an indispensable ingredient for demanding applications requiring enhanced structure, moisture retention, emulsification, and cleaning performance.

VI. Safety and Regulations: Is TSP Safe to Use?

As a food additive, Trisodium Phosphate (TSP) has been approved by regulatory authorities in multiple countries and is classified as a globally accepted inorganic phosphate additive. Its safety profile in use is reflected in the following standards:

Region / Authority	Key Standards and Conclusions
China	Food-grade TSP must comply with GB 1886.25–2016: purity ≥ 98.0%, lead ≤ 2 mg/kg, arsenic ≤ 3 mg/kg. Under GB 2760–2024, the maximum allowable usage in meat products is ≤ 5.0 g/kg (calculated as PO₄³⁻).
European Union	Listed as E339 (iii), approved for use in food processing. The acceptable daily intake (ADI) is set at 0–70 mg/kg body weight (as phosphorus), with total phosphate intake requiring oversight.
United States (FDA)	Classified as a GRAS substance (Generally Recognized As Safe), approved for use in canned goods and baked products. Heavy metals and impurities must meet safety thresholds.

⚠️ Important Distinction: Food-Grade vs. Industrial-Grade TSP

Item	Food-Grade TSP	Industrial-Grade TSP
Application	Food processing, formulations, cleaning in food environments	Cleaning agents, water treatment, metal surface preparation
Purity Requirement	≥ 98.0%, with strict limits on heavy metals	Typically ≥ 90%, may contain acceptable levels of impurities
Edibility	✅ Safe under regulated use	❌ Not permitted for food or animal feed use
Regulatory Compliance	GB / FDA / EFSA / KOSHER / HALAL	Not subject to food-grade regulations

📌 Regulatory Notes:

• Although TSP is non-toxic, its strong alkalinity may irritate the mouth or digestive tract if used improperly. Therefore, it must be strictly limited according to national regulations to avoid overuse.

• Food product labels must correctly identify it as a “phosphate food additive”, and naming should conform to national standards (e.g., E339(iii) in the EU, INS 339(iii) in other Codex-aligned countries).

• For use in Halal or Kosher-certified products, relevant certification is required.

VII. Key Differences Between TSP and Other Phosphates

In food processing and cleaning formulation, common inorganic phosphates include Trisodium Phosphate (TSP), Disodium Phosphate (DSP), and Sodium Tripolyphosphate (STPP). While all originate from sodium phosphate systems, their degree of neutralization leads to significant differences in pH, metal chelating ability, and application scope.

Below is a comparative table of their core characteristics:

Property	Trisodium Phosphate (TSP)	Disodium Phosphate (DSP)	Sodium Tripolyphosphate (STPP)
Chemical Formula	Na₃PO₄	Na₂HPO₄	Na₅P₃O₁₀
pH (1% solution)	11.5–12.0 (strongly alkaline)	9.0–9.4 (mildly alkaline)	9.5–10.0 (moderately alkaline)
Metal Chelating Ability	★★★★★	★★☆☆☆	★★★★☆
Thermal Stability	Very high (>200°C)	Moderate	Moderately high
Typical Applications	Hard water treatment, CIP cleaning, water retention in meat, protein unfolding	Buffering in dairy, pH adjustment in baked goods, plant-based drinks	Detergents, moisture retention in meat products, phosphate blends
Main Advantages	Strongest in both alkalinity and chelation, ideal for challenging water scales or protein restructuring	Gentle pH, suitable for sensitive formulations like dairy and sponge cakes	Strong moisture retention and good chelation, but milder alkalinity
Common Food-Grade Use	✅ Common in marinated meat, plant-based products, ready meals	✅ Common in powdered milk, baking premixes	✅ Common in surimi, frozen meat, seafood

📌 Practical Application Suggestions:

Application Scenario	Recommended Product	Reason
Flaky pastry and soft dough	DSP + TSP	pH adjustment + gluten structure enhancement
Water retention and freeze-thaw stability in surimi products	STPP	Excellent moisture retention, reduces ice crystal damage
Preventing sedimentation in high-calcium milk powder	DSP	Neutralizes free Ca²⁺, maintains system stability
CIP cleaning of factory equipment	TSP	Strong alkalinity + high chelation for rapid scale removal
Tenderizing meat in canned foods	TSP + STPP	Protein relaxation + synergistic water retention

🧠 Additional Knowledge:

• TSP is a fully neutralized phosphate salt, exhibiting the strongest alkalinity and chelation capacity;

• DSP is partially neutralized, with mild alkalinity;

• STPP is a polyphosphate, known for its excellent chelating and emulsifying power, but provides moderate pH adjustment, making it less suitable where high alkalinity is required.

VIII. Conclusion: The "All-Around Value" of TSP

Trisodium Phosphate (TSP) stands as the functional powerhouse within the inorganic phosphate family. Its value extends far beyond mere alkalinity — offering structural control, metal chelation, pH stabilization, high-temperature tolerance, and controlled safety. It serves as a bridging material between food technology and industrial processing.

From a food industry perspective, TSP is a key additive that:

• Enhances water retention in meat products,

• Stabilizes dairy systems,

• Reinforces the structure of plant proteins.

From an industrial standpoint, it is a powerful tool for:

• Combating hard water scaling,

• Cleaning heavy grease and residues,

• Optimizing pre-treatment for electroplating.

TSP proves that an outstanding ingredient does not need flashy packaging — its strength lies in protecting quality and improving efficiency behind the scenes.

🏁 Final Message from Kelewell

At Kelewell, we recognize that precise functional performance and regulatory compliance are essential in every food formulation. That’s why when it comes to food-grade Trisodium Phosphate (TSP), we uphold rigorous quality standards from raw material selection to final delivery.

Whether it’s acting as a powerful pH adjuster to optimize protein structure, a chelating agent to improve water-binding capacity in meat and seafood products, or a cleaning aid for hygienic food processing environments — our TSP delivers consistent, efficient, and globally compliant functionality across meat processing, dairy, bakery, and more.

We welcome all technical discussions, regulatory documentation requests, and custom packaging inquiries to fully support your product development and market access.

📩 For detailed specifications, samples, or tailored solutions, feel free to contact us anytime —Kelewell, advancing every step of food innovation with you.