Sodium Metabisulfite

Molecular formula: Na2S2O5, relative molecular weight: 190.09, appearance: white or slightly yellow crystalline powder with intense odor, melting point: 300 ℃, relative density d415:1.4, solubility: easily soluble in water and glycerol, slightly soluble in alcohol. The aqueous solution is acidic, and the pH value of the 1% aqueous solution is between 4.0 and 5.5. Application performance: Bisulfate has a more intense reducing effect, similar to sodium sulfite. Dosage: according to Chinese regulations, sodium metabisulfite can be used for preserves, biscuits, glucose, sugar, rock sugar, candy, liquid glucose, bamboo shoots, mushrooms, and canned mushrooms. The maximum usage amount is 0.45g/kg, and the residual amount is calculated as sulfur dioxide. Bamboo shoots mushrooms and canned mushrooms shall not exceed 0.05g/kg; Biscuits, sugar, vermicelli, and other varieties shall not exceed 0.1g/kg; Liquid glucose should not exceed 0.2g/kg; Candied fruit should not exceed 0.05g/kg. The residual amount shall not exceed 0.05g/kg (calculated as SO2). Safety: Intravenous injection of LD50 in rats: 115mg/kg, AID 0-0.7mg/kg (calculated as SO2, including total ADI of SO2 and; FAO/WHO, 1999), GRAS (FDA, § 182.37662000).

Sodium metabisulfite has obvious irritating effects on the skin and mucous membranes, and can cause symptoms of conjunctivitis and bronchitis. People with allergic constitution or asthma are very sensitive to this. Direct contact with the skin can cause burns. Staff should take proper precautions. Store in a cool, dry, and well ventilated warehouse. Keep away from sparks and heat sources. Keep the container sealed. It should be stored separately from oxidants, acids, and edible chemicals, and should not be mixed for storage.

Production method: It is obtained by extracting sulfur from a pure alkali aqueous solution and burning it, and then drying it separately.

Dosage and Safety of Sodium Metabisulfite and Potassium Metabisulfite

Potassium metabisulfite

Molecular formula: K2S2O5, relative molecular weight: 222.33, appearance: white crystalline or crystalline powder with slight odor, melting point: decomposes when heated to 190 ℃, grinds into powder and can burn when heated, relative density d415:2.300, solubility: easily soluble in water (44.9g/100mL, 20 ℃), aqueous solution is acidic, and 1% aqueous solution has a pH value of 3.4-4.5.

Application performance: used as a bleaching agent, preservative, antioxidant, color protector, stabilizer, etc. Easy to dissolve in water, can be used to prepare aqueous solutions straight. It has a strong inhibitory effect and a more intense reducing effect on plant-based foods. Used for bleaching and color protection of novel fruits and vegetables, sugars, and the addition of meat, wine, and beverages is mainly for the purpose of preservation. Dosage: According to Chinese regulations, it can be used for preserves, biscuits, candy, glucose, rock sugar, bamboo shoots, mushrooms, and canned mushrooms, with a maximum dosage of 0.45g/kg; It can also be used for beer, with a maximum usage of 0.01g/kg. The residual amount shall not exceed 0.05g/kg for bamboo shoots, mushrooms, and canned mushrooms; Biscuits, sugar, and other varieties shall not exceed 0.1g/kg; Liquid glucose should not exceed 0.2g/kg; The residual amount of candied fruit is 0.05g/kg.

Safety: Rabbit oral LD50: 600-700mg/kg (calculated as SO2). ADI 0-0.7mg/kg (calculated as SO2, including total ADI of SO2 and; FAO/WHO, 2001), GRAS (FDA, § 182.36372000).

Production method: Inject refined gas into the solution to obtain the solution, and then go through steps such as stirring, concentration, and drying to finally obtain potassium metabisulfite crystals.