What is Sodium Metabisulfite?
Sodium metabisulfite has a strong SO2 odor and is visible as a white crystalline powder. It produces matching salts and releases SO2 when it comes into touch with strong acid. The product cannot be kept for an extended period of time since it oxidizes to Na2S2O6 when exposed to air for an extended period of time.
This substance is specifically used as an antioxidant, bleaching agent, etc. in the food, chemical, and pharmaceutical industries.
There are several methods for preparing food-grade sodium metabisulfite in China:
- Sulfur reacts with alkaline carbonates at appropriate temperature and reaction conditions to generate thiosulfate, and then further oxidizes to generate pyrosulfite. This method has become the mainstream production process due to its stability, high efficiency and low cost.
- Another common preparation method is to oxidize sodium sulfite to sodium pyrosulfite. This method can directly use sodium sulfite as a raw material without sulfur treatment.
- Sodium pyrosulfite is generated by reacting sulfur dioxide with alkaline carbonates. This method is mainly suitable for production under specific process requirements and resource conditions.
Related parameters:
| ITEMS | STANDARD |
| Content % | ≥ 96.5 |
| Heavy Metals (Fe) % | ≤ 0.003 |
| Heavy Metals( As) % | < 0.0001 |
| Charity | Slightly turbid |
| SO2>=</p> | 65 |
| PH | 4.0-5.0 |
| Heavy Metals( Pb)% | ≤ 0.0005 |
Recommended dosage:
| Food name | Maximum usage(g/kg) |
| Bread and dough products | 0.3 – 1.0 g/kg |
| Biscuits | 0.1 – 0.5 g/kg |
| Pizza | 0.3 – 1.0 g/kg |
| Hamburgers, sandwiches | 0.1 – 0.5 g/kg |
| Fried chicken | 0.1 – 0.5 g/kg |
| Candy | 0.05 – 0.2 g/kg |
| Chocolate products | 0.05 – 0.2 g/kg |
| Carbonated drinks | 0.02 – 0.1 g/kg |
| Dairy products | 0.02 – 0.1 g/kg |
| Seasonings | 0.02 – 0.1 g/kg |
| Canned food | 0.02 – 0.1 g/kg |
| Prepared food | 0.01 – 0.05 g/kg |
| Seafood products | 0.01 – 0.05 g/kg |
Sodium Metabisulfite has a wide range of uses
- Food shelf life can be increased by sodium metabisulfite’s ability to efficiently suppress oxidation reactions in food and stop fats and oils from oxidizing. It prevents food from deteriorating, changing in taste, and distorting in color due to oxidation by capturing oxygen molecules or reacting with oxygen as a reducing agent.
- In food processing, sodium metabisulfite is used as a bleaching agent, especially for vegetables, fruits, and seafood products, to help remove or reduce pigments or colors in products and improve the appearance and visual appeal of products.
- Sodium metabisulfite can delay the natural changes and degradation of food by inhibiting the activity of enzymes. For example, during the cutting and processing of fruits and vegetables, it can reduce oxidation and browning caused by enzymatic action.
- Sodium metabisulfite can also be used as a mildew inhibitor in certain food manufacturing processes to prevent the formation of bacteria and mold, prolonging the shelf life and freshness of food.
- Sodium metabisulfite can be used to adjust the pH of products in food processing, helping to maintain a suitable pH range to optimize the taste, texture, and stability of food.
User asked question:
Q: So far, what is the market demand for food-grade sodium pyrosulfite? Where is it mainly concentrated?
A: The market demand for food-grade sodium pyrosulfite remains stable, mainly concentrated in North America, such as the United States and Canada, followed by European countries, especially in the food processing industry, covering a wide range of fields from bread and pastries to alcoholic beverages.
The price of food-grade sodium pyrosulfite in China has dropped, but the decline is not large.
