Commercial sodium hexametaphosphate is a mixture of various polyphosphates, that is, one of them. It is a multivalent chelating agent and widely used in industry, including as a food additive. Sodium carbonate can be added to sodium hexametaphosphate to raise its pH to 8.0-8.6, which can be used as hard water softener and cleaner. It can stabilize natural pigments in beans, canned fruits and vegetables and bean paste fillings, and protect food color; Fat can be emulsified in canned meat to keep the texture uniform; Used in canned meat and meat products, it can improve water holding capacity and prevent fat deterioration. Adding it to beer can clarify the liquor and prevent turbidity.

There will be trace heavy metals such as arsenic and lead in sodium hexametaphosphate, and arsenic will cause systemic chronic poisoning, mainly depigmentation, pigmentation, keratinization and canceration of skin. Food-grade sodium hexametaphosphate also contains a certain amount of fluoride. Low concentration of fluoride can cause chronic poisoning and skeletal fluorosis, reduce calcium in bones, and lead to sclerosis and osteoporosis.

Potassium sorbate, also known as potassium 2,4- hexadienoate, is the potassium salt of sorbic acid, which is colorless or white to light yellow flake crystals, crystalline powder or particles. Odorless or slightly smelly. It is unstable in the air, and it absorbs moisture and oxidizes and decomposes for a long time to be colored. Soluble in water. Basically non-toxic. It is mainly used as a food preservative, and can also be used for cosmetics preservation and feed mildew prevention. It has a strong inhibitory effect on spoilage bacteria and mold, is soluble in water and has very low toxicity, so it has been widely used.

Potassium sorbate is safe, it can be absorbed by the metabolic system of human body and quickly decomposed into carbon dioxide and water, and there is no residue in the body. Generally, the amount of additives in food is very safe as long as it does not exceed the limit requirements. If it exceeds the limit seriously and is taken for a long time, it will inhibit the growth of bones to a certain extent and endanger the health of kidneys and livers.