Nutrition Diet: What does disodium hydrogen phosphate do?

October 11, 2025 •

4 min read

Disodium hydrogen phosphate (DSP), also known as E339(ii), is a multifunctional food additive that has been widely used in food processing for over a century. This inorganic salt, derived from phosphorus and sodium, serves several key technical purposes that impact the quality, safety, and shelf-life of a wide array of products. Understanding what does disodium hydrogen phosphate do is crucial for making informed decisions about your dietary intake.

Quick Summary

Disodium hydrogen phosphate is a common food additive that functions as an emulsifier, stabilizer, and pH regulator in processed foods. Its primary roles include preventing ingredient separation, preserving texture and flavor, and extending shelf life. It is also a source of the essential mineral phosphorus.

Key Points

Emulsifier: DSP helps bind fats and water, ensuring a smooth, uniform texture in dairy products like processed cheese and evaporated milk.
pH Regulator: As a buffering agent, it stabilizes the acidity of foods, which helps preserve flavor, color, and prevents the growth of harmful bacteria.
Stabilizer and Preservative: It prevents ingredients from separating and helps extend the shelf life of many processed foods.
Phosphorus Source: It serves as a source of phosphorus, a mineral vital for bone health and energy metabolism, though the phosphorus in additives is absorbed more readily than in whole foods.
Health Risks: While generally recognized as safe, excessive consumption of DSP-containing processed foods can lead to high phosphate and sodium intake, which is a concern for individuals with kidney disease.
Dietary Control: Conscious consumers can manage their intake by reading ingredient labels and limiting their consumption of processed foods in favor of whole, unprocessed options.

What is Disodium Hydrogen Phosphate?

Disodium hydrogen phosphate (DSP), also called disodium phosphate or sodium phosphate dibasic, is an inorganic chemical compound with the formula $Na_2HPO_4$. In the food industry, it is identified by the European food additive number E339(ii). It is a white, odorless powder that is highly soluble in water and slightly alkaline. DSP is synthetically produced by treating naturally occurring phosphate rock to extract phosphorus compounds, which are then combined with sodium. While some phosphate compounds are naturally present in foods, the form used in processed products is manufactured to achieve specific functional properties.

Multifunctional Roles in Processed Foods

Disodium hydrogen phosphate performs a variety of functions that are vital to the mass production and stability of processed foods. Without it, many of the textures and shelf-lives we expect from convenience foods would be difficult to achieve.

Emulsifier and Stabilizer

One of the most important roles of disodium hydrogen phosphate is acting as an emulsifier. It helps to bind oil and water together in mixtures that would otherwise separate. This is particularly important for dairy products like processed cheese and evaporated milk, where it prevents the separation of butterfat and other components, ensuring a smooth, uniform texture. In whipped cream, it prevents the cream from becoming unmanageable during processing and helps stabilize its final form.

pH Control Agent

Maintaining a stable pH level is critical for preserving a food's flavor, color, and nutritional value, as well as for ensuring safety by inhibiting bacterial growth. DSP acts as a buffering agent, resisting changes in acidity or alkalinity throughout the production and storage process. This function is used in a range of products from canned foods to sodas to ensure consistency and prevent spoilage.

Preservative and Moisture Retention

Both the sodium and phosphorus components of DSP contribute to extending the shelf life of foods. In addition to its preservative qualities, it is used in meat and poultry processing to retain moisture, which enhances the juiciness and tenderness of the final product. This property also helps prevent corrosion in metal packaging, which is beneficial for canned goods.

Anti-Caking Agent and Leavening

In powdered food products like milk, spices, and instant puddings, DSP prevents clumping, ensuring a smooth, free-flowing texture. In baking, it can also act as a leavening agent by controlling the pH of dough, which is essential for proper rising and achieving the desired texture in baked goods.

Nutritional Considerations and Health Implications

On the nutritional front, disodium hydrogen phosphate is a source of phosphorus, a mineral essential for various bodily functions, including energy metabolism and bone health. However, the phosphorus in additives like DSP is generally absorbed more efficiently than naturally occurring phosphorus in whole foods.

While regulatory bodies like the FDA and EFSA have deemed DSP safe for consumption within regulated limits, health concerns arise primarily from excessive intake, which is more common with a diet high in processed foods. High phosphate intake can be particularly problematic for individuals with kidney disease, as impaired kidneys struggle to filter out excess phosphorus. This can lead to hyperphosphatemia, a condition associated with heart disease and ectopic calcification. Additionally, the high sodium content of many processed foods containing DSP can contribute to high blood pressure and water retention, especially in susceptible individuals.

Comparison of Common Food Phosphates


Feature	Disodium Hydrogen Phosphate (DSP)	Monosodium Phosphate (MSP)	Trisodium Phosphate (TSP)
Chemical Formula	$Na_2HPO_4$	$NaH_2PO_4$	$Na_3PO_4$
pH Level	Moderately alkaline (approx. 9.0)	Acidic	Strongly alkaline
Primary Use in Food	Emulsifier, stabilizer, pH buffer for dairy, meat	pH buffer, leavening agent for baked goods, beverages	Emulsifier, buffer for cheese and meat processing
Impact on Flavor	Neutral, balanced impact	Can introduce a slightly acidic taste	Strong alkaline taste
Best For	Applications needing a balanced pH, like processed cheese and meats	Applications requiring an acidic environment, such as some bakery items	Industrial applications and specific food processes requiring high pH

Making Informed Dietary Choices

Given the widespread use of disodium hydrogen phosphate and other additives in processed foods, here are some strategies for managing your dietary phosphate intake:

Read Labels Carefully: Always check the ingredients list on packaged food. Disodium hydrogen phosphate might be listed under synonyms like disodium phosphate or its E-number, E339(ii).
Favor Whole Foods: A diet rich in natural, unprocessed foods—like lean meats, fruits, vegetables, and whole grains—is the best way to ensure you're getting essential nutrients without excessive additives.
Limit Processed Dairy and Meats: Be mindful of your consumption of processed cheeses, deli meats, and pre-packaged poultry, which often contain higher levels of added phosphates.
Consider Cooking from Scratch: Preparing meals at home with fresh ingredients gives you complete control over your food's content, allowing you to avoid unnecessary additives.
Stay Hydrated: Proper hydration is important for kidney function, which helps manage phosphate levels in the body.

Conclusion

To answer what does disodium hydrogen phosphate do is to explore its multifaceted role as a workhorse additive in modern food production. It serves essential functions like emulsifying, stabilizing, and preserving, which are critical for the textures and longevity of many popular foods. As a source of phosphorus, it can contribute to a person's nutritional needs, but excessive intake from processed sources can pose health risks, particularly for individuals with kidney issues. By understanding its purpose and being mindful of its presence in our diets, consumers can make more conscious and healthy food choices.

Foods That May Contain Disodium Hydrogen Phosphate

Processed cheese and cheese sauces
Evaporated and powdered milk
Instant puddings and desserts
Processed meats and seafood
Sodas and certain beverages
Canned foods
Baked goods
Gelatin powder

Frequently Asked Questions

The purpose of disodium hydrogen phosphate in food is to act as an emulsifier, stabilizer, and pH regulator. It helps keep ingredients mixed, maintains texture, controls acidity, and extends shelf life.

When consumed within regulated limits, disodium hydrogen phosphate is generally considered safe. However, excessive intake, particularly from a diet high in processed foods, can be a concern for people with kidney disease or those needing to limit sodium intake.

In cheese, disodium hydrogen phosphate acts as an emulsifier, preventing the fats and water from separating. This creates a smooth, consistent texture in processed cheese products and prevents coagulation during heating.

Disodium hydrogen phosphate is found in many processed foods, including certain types of cheese, evaporated milk, instant puddings, sodas, and processed meats. It will be listed in the ingredients or by its food additive code, E339.

Yes, phosphates from additives like DSP have a higher bioavailability than naturally occurring phosphates in whole foods. This means the body absorbs and utilizes them more easily and in larger quantities, which can impact overall mineral balance.

The main difference is their chemical composition and pH level. Disodium hydrogen phosphate ($Na_2HPO_4$) is moderately alkaline, while trisodium phosphate ($Na_3PO_4$) is strongly alkaline.

To reduce your intake of added phosphates, you should prioritize eating whole, unprocessed foods and check the ingredient labels of packaged products. Limiting processed meats, fast food, and certain dairy products is also effective.