Food-grade sodium metabisulfite can be used in food processing to improve the taste of food. The main uses are as follows:
　　 1. Bleaching agent Used to bleach the flour used in the manufacture of cakes and other foods.
　　Second, leavening agent can make the structure of food such as bread and biscuits become loose, and the taste is relatively crisp.
　　3. Antiseptic and antiseptic agent Adding to fruit juice, preserves and canned food can prolong the shelf life of food and carry out effective sterilization.
　　4. Antioxidant anti-staling agent has a good anti-oxidation and preservation effect on seafood, fruits and vegetables.
Sodium metabisulfite is white or yellow crystalline powder or small crystals, with a strong SO2 odor, specific gravity 1.4, soluble in water, the aqueous solution is acidic, and when contacted with strong acid, SO2 will be released to form corresponding salts. It will be oxidized if left in the air for a long time. It becomes Na2S2O6, so the product cannot be stored for a long time. Above 150 degrees Celsius, SO2 is decomposed.