Water retention agent refers to a kind of substance which can improve the stability of products, keep the internal water retention of food water retention agent and improve the shape, flavor and color of food. Food grade sodium tripolyphosphate helps to maintain the water content in food. It is mainly used in meat and aquatic products processing to enhance the water stability and high water holding capacity.

Several principles for selecting moisture retention agent products:

1. The ability of preserving water and making color of marinated meat stuffing: after marinating, the meat stuffing will have elasticity and brightness;

2. The product's solubility and retention agent can only be used after dissolving. The product with poor solubility can't play the role of product 100%.

3. Taste of the product: the phosphate with poor purity and quality will have astringency when it is made into meat products and tasted, which is most obvious on both sides of the root of the tongue, followed by the details such as the taste crispness of the product.

4. The compound additive has good flavor and synergistic effect, avoiding the disadvantages of single product such as astringent flavor, poor solubility, salting out and no significant effect.

5. PH value, PH 8.0-9.0, too strong alkaline, serious tenderized meat, resulting in loose product structure, unsmooth slice, poor elasticity.

Food grade sodium tripolyphosphate in meat products can maintain the water holding capacity of meat, enhance the cohesion, and maintain the nutritional composition and tenderness of meat. The mechanism of improving the water holding capacity of meat is that it can improve the PH of meat and make it deviate from the isoelectric point (hp5.5) of meat protein. Chelate the metal ions in meat, make the protein in muscle tissue chelate with calcium and magnesium ions. Increasing the ionic strength of meat is conducive to the transformation of muscle protein into loose state.