Sodium Tripolyphosphate

What is sodium tripolyphosphate used for?
Sodium tripolyphosphate has the functions of chelating, suspending, dispersing, peptizing, emulsifying, pH buffering, etc., and can be used as the main auxiliary agent of synthetic detergent, industrial water softener, pretanning agent for tanning, dyeing auxiliary agent, organic synthesis catalyst , pharmaceutical industry dispersants and food additives, etc.
What is the use of sodium tripolyphosphate in detergent?
Mainly used as a builder for synthetic detergents, for soap builders and to prevent bar soap grease and blooming. It has a strong emulsifying effect on lubricating oil and fat, and can be used to adjust the pH value of buffer soap.
Sodium tripolyphosphate is an indispensable and excellent additive in detergents, and its main functions can be summarized as follows.
① Chelation of metal ions
Daily washing water generally contains hard metal ions (mainly Ca2+, Mg2+). During the washing process, they will form insoluble metal salts with the active substances in the soap or detergent, which not only increases the consumption of detergent, but also gives the washed fabrics an unpleasant dark gray color. Sodium tripolyphosphate has the excellent performance of chelating hard metal ions, thereby eliminating the adverse effects of these metal ions.
② Improve the effect of peptization, emulsification and dispersion
Dirt often contains human secretions (mainly protein and fatty substances), as well as sand and dust from the outside. Sodium tripolyphosphate has the effect of swelling and solubilizing protein and peptizing effect; it can promote emulsification for fatty substances; it can disperse and suspend solid particles.
③Cushioning effect
Sodium tripolyphosphate has a large alkaline buffering effect, which keeps the pH value of the washing solution at about 9.4, which is beneficial to the removal of acidic dirt.
④The role of preventing agglomeration
Powdered synthetic detergents are hygroscopic, and if stored in a place with high humidity, caking will occur. The caked detergent is extremely inconvenient to use. The hexahydrate formed after sodium tripolyphosphate absorbs water has a dry characteristic. When there is a large amount of sodium tripolyphosphate in the detergent formula, it can prevent the agglomeration caused by moisture absorption and keep the synthetic detergent dry and granular.
How is STPP made?
Polyphosphates are formed by linking together many simple phosphate units, and sodium tripolyphosphate contains three such units.
The brief manufacturing process is as follows:
STPP is produced commercially by neutralizing phosphoric acid with sodium hydroxide to form a mixture of monosodium phosphate and disodium phosphate. The mixture is then heated to 500-550 °C. Here is the reaction equation: NaH2PO4 + 2Na2HPO4 → Na5P3O10 + 2H2O
Food-grade STPP exists in two forms and follows a corresponding chemical formula: STPP anhydrous: Na5O10P3
STPP hexahydrate: Na5O10P3 6H2O
What is sodium tripolyphosphate used for?
With water retention capacity, the main use of food grade sodium tripolyphosphate is to improve the eating quality in food processing, especially in meat and fish products. It is also used in pet foods, such as those for cats and dogs, to bind moisture and keep animal feed fresh.
It can also be used as a food starch modifier.
Industrial grade STPP has the functions of chelating metal ions, suspending, dispersing, emulsifying, pH buffering, etc. Tanning agents, dyeing auxiliaries, etc. What does sodium tripolyphosphate do to meat?
Phosphate is widely used in meat processing, and its main uses are as follows:
Water retention, emulsion stability, juiciness and tenderness
Slows down the rate of oxidative decay
Improves color and maintains flavor
Phosphates commonly used in meat production include sodium polyphosphate, sodium pyrophosphate, and sodium hexametaphosphate.
Polyphosphates are commonly used additives in meat processing. Adding STPP to meat can improve texture and color, reduce cooking losses, and increase product yield. This mechanism is thought to be by increasing pH, enhancing ionic capacity and chelating metal ions.
STPP interacts with amino acids or hydroxyl groups in proteins, thereby improving water retention and gel strength of meat.
At the same time, its combination with sodium chloride can reduce the sodium content of meat compared to using sodium chloride alone. NaCl contains 39.3% sodium, while sodium tripolyphosphate (anhydrous) contains only 31.3% sodium.