Sodium metabisulfite is a widely used additive in the food industry. It is used in various foods such as meat products, aquatic products, beverages, malt drinks, soy sauce, etc., as an antioxidant, preservative, and bleach. In addition, sodium metabisulfite can also be used to make desserts such as candies, canned goods, jams, and preserves to enhance their shelf life and taste. Sodium metabisulfite also plays an important role in the fields of fuel industry catalysts, papermaking industry bleaches, pharmaceutical additives, and chemical additives in dye and textile processes.
As a food additive, the main function of sodium metabisulfite is to exert its antioxidant and preservative effects. During food processing, sodium metabisulfite can effectively inhibit the oxidation reaction of fats, delay the rate of food spoilage, and thus extend the shelf life of food. Meanwhile, sodium metabisulfite can also inhibit the growth of bacteria and mold in food, preventing food from being contaminated by microorganisms. This antioxidant and antibacterial effect is achieved by the decomposition of sodium metabisulfite to produce sulfur dioxide and sulfite ions.
There are two production process routes for sodium metabisulfite: dry method and wet method：
(1) Dry method. Mix soda ash and water in a certain molar ratio evenly, and when Na2CO3. nH2O is generated in block form, place it into the reactor. Maintain a certain gap between the blocks and then introduce SO2 until the reaction is complete. Take out the block and crush it to obtain the finished product.
(2) Wet method. Add a certain amount of pure alkali to the sodium bisulfite solution to generate a suspension of sodium bisulfite, then introduce SO2 to generate sodium pyrosulfite crystals, which are centrifuged and dried to obtain the finished product.
Main uses
Used for producing insurance powder, sulfamethoxazole, acetaminophen, caprolactam, etc; Used for the purification of chloroform, phenylpropylsulfone, and benzaldehyde. Ingredients used as fixing agents in the photography industry; The spice industry is used to produce vanillin; Used as a preservative in the brewing industry; Rubber coagulants and dechlorinating agents for bleached cotton fabrics; Organic intermediates; Used for printing, dyeing, and leather making; Used as a reducing agent; Used for wastewater treatment in the electroplating industry, oil fields, and as mineral processing agents in mines; Used as a preservative, bleach, and loosening agent in food processing
The main function of sodium metabisulfite is as an oxidant.
In industry, it is mainly used for printing and dyeing, organic synthesis, printing, leather making, pharmaceuticals, etc. In food processing, it is mainly used as a preservative, bleach, and loosening agent.
Sodium metabisulfite is commonly used as a preservative in the brewing industry, and in the textile industry as a dechlorinating agent after cotton fabric bleaching.
Precautions for using sodium metabisulfite
Sodium metabisulfite may cause harm to human renal function, and in severe cases, it can lead to acute poisoning and even death. People must take safety precautions when using it.
The product has a stimulating effect on the skin and mucous membranes of the human body, which can cause symptoms such as conjunctivitis and bronchitis. People with allergies or asthma should not come into contact with this product, as direct skin contact can cause burns.
The product should be stored in a cool, dry, and well ventilated place, away from flames, and kept in a sealed container. It should be stored separately from oxidants to prevent explosions.
When using, safety goggles, specialized work clothes, and rubber gloves should be worn to avoid direct contact with the product