Sodium Metabisulfite: Properties, Applications, and Essential Uses in the Food Industry
- Sanita
- Dec 2
- 3 min read
Updated: 2 days ago
Sodium Metabisulfite (SMBS), known by the additive code E223, is a powerful and widely used preservative, antioxidant, and anti-browning agent essential for protecting the freshness, colour, safety, and stability of food products. Prized for its strong antimicrobial properties, it prevents microbial growth and enzymatic reactions that can degrade quality, making it indispensable in dried fruits, beverages, seafood, starch processing, fruit preparations, and dough conditioning.
As manufacturers seek effective and economical preservation solutions, Sodium Metabisulfite remains one of the most trusted functional ingredients for extending shelf life and maintaining high-quality standards across modern food manufacturing.
Table of Content
What Is Sodium Metabisulfite?
Sodium Metabisulfite (Na₂S₂O₅) is a white to yellowish crystalline powder with a characteristic sulphur odour. In food applications, it releases sulphur dioxide (SO₂), which performs the preservative and antioxidant functions.
Key Characteristics
Appearance: White or pale yellow crystalline powder
Odour: Mild sulphur smell
Solubility: Highly soluble in water
Functions: Preservative, antioxidant, antimicrobial, anti-browning agent
Regulatory Status: Approved food additive, E223
Sodium Metabisulfite is widely used not only in food, but also in pharmaceuticals, water treatment, and industrial applications. However, its food industry role remains the most significant.
What are the Benefits of Sodium Metabisulfite for the Food Industry?
Preservative and Antimicrobial Agent
The sulphites released from Sodium Metabisulfite inhibit the growth of:
Bacteria
Yeasts
Moulds
This makes it highly effective for preserving perishable foods and preventing spoilage during storage and transportation.
Anti-Browning Agent
One of its major uses is preventing enzymatic browning in fruits and vegetables. It helps maintain fresh colour by inhibiting polyphenol oxidase activity.
Applications include:
Dried fruits
Cut potatoes
Fruit pulps and purees
Canned and processed fruits
This property ensures fruits remain visually appealing and stable during processing.
Antioxidant Protection
Sodium Metabisulfite protects foods from oxidation by scavenging oxygen and reactive compounds.
This helps:
Prevent rancidity in foods containing fats and oils
Preserve vitamins (especially Vitamin C)
Maintain flavour and aroma stability
Reduce oxidative discolouration
Its antioxidant capability is particularly useful in beverages and processed foods.
Dough Conditioner in Bakery
In bakery applications, Sodium Metabisulfite acts as a reducing agent, helping to:
Relax gluten
Improve dough extensibility
Enhance machinability
Reduce mixing time
It is especially important in:
Cookie dough
Cracker dough
Biscuit production
Industrial dough sheeting operations
Colour Protection in Seafood
Sodium Metabisulfite is widely used in the seafood industry—especially for shrimp—to prevent black spot formation (melanosis).
It preserves quality by:
Inhibiting enzymatic browning on crustaceans
Maintaining the natural appearance of shrimp during storage and transport
Stabilizer in Beverages and Wine
In beverages, Sodium Metabisulfite:
Prevents microbial fermentation
Protects flavour compounds
Stabilizes colour
Extends shelf life
It is commonly used in:
Wine
Beer
Juices
Carbonated beverages
Product Presentation and Commercial Forms
Sodium Metabisulfite is produced in a variety of grades tailored for different industrial and food applications.
Food Grade (E223)
High purity
Low impurity content
Suitable for direct addition to foods, beverages, and processing solutions
Industrial Grade
Used for water treatment, textiles, and industrial processing
Not intended for food use
Powder Form
Most common
Fast dissolving
Ideal for fruit processing, seafood treatment, wine production
Granular Form
Reduced dust
Improved flowability
Suitable for large-scale processing or automated dosing
Quality Standards/Packaging
25 kg bags
25–50 kg drums
Moisture-resistant packaging
Food-grade products typically comply with FCC, USP/EP, E223, GB and international food safety regulations.
Storage and Handling Considerations
Because Sodium Metabisulfite is moisture-sensitive and reacts with acids, proper storage is essential:
Store in a cool, dry, well-ventilated area
Keep away from moisture
Avoid contact with acids (releases sulphur dioxide gas)
Use tightly sealed packaging
Follow allergen labelling regulations for sulphites
Regulations and Allergen Considerations
Many countries require labelling when sulphite content in foods exceeds 10 ppm, as some individuals may be sensitive to sulphites.
Regulations cover:
Maximum allowable levels in various foods
Allergen warnings on packaging
Specific limits for dried fruits, potatoes, seafood, wine, and beverages
Market Trends and Industry Insights
Demand for Sodium Metabisulfite continues to grow due to:
Rising global consumption of processed fruits and vegetables
Expansion of the wine and beverage industry
Increased seafood exports
Need for effective preservatives in ready-to-eat foods
Despite the rise of “clean-label” trends, Sodium Metabisulfite remains indispensable due to its unmatched technical effectiveness.
Conclusion
Sodium Metabisulfite is a highly versatile and essential food additive with powerful preservative, antioxidant, antimicrobial, and anti-browning properties. Its role in maintaining colour, flavour, safety, and shelf life makes it invaluable in fruit processing, beverages, bakery, seafood, and many other food applications.
While regulatory compliance and sulphite sensitivity must be considered, Sodium Metabisulfite remains one of the most effective and widely used preservation tools in modern food manufacturing.
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