Calcium Sulphite
Calcium Sulphite, commonly referenced as E226 / INS 226, is an inorganic sulphite additive reviewed for preservative, antioxidant, oxygen-scavenging and shelf-life support functions in selected food systems where permitted. For industrial buyers, the real purchasing value depends on food-grade identity, assay, sulphite content, SO2-equivalent value, solubility behaviour, hydrate form, calcium contribution, sulphate impurity, particle size, oxidation stability, sulphite declaration requirements, regulatory fit, documentation quality and batch-to-batch consistency.
Sulphite performance depends on pH, dissolved oxygen, water activity, SO2-equivalent dose, solubility, contact time, product matrix, processing conditions and destination-market rules.
Product identity
| Product | Calcium Sulphite |
|---|---|
| Alternative names | Calcium Sulfite; Calcium Sulphite E226; Calcium Sulfite E226; INS 226; sulfurous acid calcium salt; CaSO3 |
| Category | Preservatives & Antimicrobials |
| Function | Preservative / antimicrobial shelf-life support |
| E / INS number | E226 / INS 226 |
| CAS / identity | 10257-55-3; confirm hydrate form, assay basis and supplier identity on COA/SDS |
| Chemical formula | CaSO3, with hydrate forms possible depending on production route and grade |
| Functional family | Sulphite preservative, reducing agent, antioxidant and oxygen scavenger |
| Typical form | White to off-white powder or granule; liquid forms should be treated as application-specific preparations and verified by supplier documentation |
| Solubility note | Low water solubility compared with many sodium or potassium sulphite salts; application trials should confirm dispersion and available sulphite release |
| Main technical value | Supports oxidation control, colour protection, oxygen scavenging and microbial-stability programs where sulphite use is permitted |
| Key buying point | Compare by SO2-equivalent contribution, assay, solubility, regulatory status and cost-in-use, not only by price per kilogram |
Industrial buying value
Calcium Sulphite is normally evaluated when a manufacturer needs a sulphite source with specific calcium, solubility or formulation characteristics. Compared with more soluble sulphite sources, Calcium Sulphite may require closer review of dispersion, contact time and available sulphite in the finished matrix. It should be specified carefully when the purchasing objective is antioxidant protection, mould or yeast inhibition, oxygen reduction or colour preservation.
- Provides sulphite functionality for selected preservative and antioxidant systems where permitted
- Can support oxygen-scavenging and reducing conditions in suitable food matrices
- May help protect colour, flavour and product quality from oxidative deterioration
- Requires SO2-equivalent calculation rather than simple kilogram-to-kilogram comparison with other sulphites
- Requires close review of sulphite labelling, hypersensitivity declaration, application limits and destination-market approval
Technical overview
Calcium Sulphite is the calcium salt of sulphurous acid. In food-additive use, its functional value comes from the sulphite ion and its reducing/oxygen-scavenging behaviour. Sulphites are used in many preservation systems because they can help reduce oxidative browning, protect sensitive colour compounds, inhibit selected yeasts and moulds, and support shelf-life design. The exact performance depends strongly on pH, available sulphite, free versus bound sulphite, product composition and processing conditions.
For procurement and R&D teams, Calcium Sulphite should not be treated as interchangeable with every sulphite salt. Sodium metabisulphite, potassium metabisulphite, sodium sulphite, sodium hydrogen sulphite, potassium hydrogen sulphite and calcium sulphite differ in active SO2-equivalent value, solubility, cation contribution, taste impact, pH impact, dosing convenience and regulatory acceptance. Substitution should be calculated and trialled in the actual application.
Sulphite functionality
Calcium Sulphite contributes sulphite chemistry, which can function as a reducing system, oxygen scavenger and preservative support in suitable applications. Performance should be validated analytically because the active form and residual level can change during processing and storage.
- Oxygen scavenging: sulphite can react with oxygen and help reduce oxidative deterioration
- Colour protection: sulphites can help control enzymatic and non-enzymatic browning in selected systems
- Microbial support: sulphites can inhibit selected yeasts, moulds and bacteria depending on pH and concentration
- Reducing conditions: sulphite can influence redox potential and interact with oxygen-sensitive ingredients
- Residual control: free and total sulphite should be measured where regulatory or label limits apply
Performance variables
The same Calcium Sulphite dose can perform differently across products. Industrial trials should evaluate the grade under actual pH, water activity, sugar, salt, oxygen exposure, heat process, packaging barrier and shelf-life conditions.
- pH and acidity, which influence sulphite antimicrobial activity and SO2 equilibrium
- Water activity, sugar solids, salt level, protein and polyphenol content
- Dissolved oxygen, headspace oxygen and package oxygen transmission rate
- Heat process, mixing, contact time, filtration and holding conditions
- Binding reactions with aldehydes, sugars, proteins or colour compounds that reduce free sulphite
Application fit
Potential use areas may include the applications below, subject to destination-market rules, food-category permission, sulphite residual limits, final label declaration and customer policy. These examples are technical formulation contexts, not a universal approval list.
| Application area | Technical reason to evaluate | Buyer / R&D checks |
|---|---|---|
| Fruit preparations and processed fruit | Oxidative browning control, colour protection and yeast/mould inhibition in selected fruit systems | pH, fruit type, enzymatic browning, SO2-equivalent level, residual sulphite, label declaration and permitted use |
| Juices, ciders and beverage bases | Oxygen scavenging, fermentation control and colour/flavour protection where sulphite use is allowed | pH, clarity, sediment, dissolved oxygen, free and total sulphite, heat process, packaging oxygen and sensory impact |
| Wine, cider and fermentation support | Microbial control and oxidation management in permitted fermentation or beverage systems | Free SO2, total SO2, pH, alcohol, yeast sensitivity, sensory impact, legal limits and label rules |
| Vegetable preparations and pickled products | Colour protection, anti-browning and microbial stability in selected acidified systems | pH, brine composition, salt, vinegar, heat process, SO2 residuals, vegetable texture and local permissions |
| Bakery and dough-related systems | Possible reducing or preservative review in selected bakery systems where permitted | Flour system, yeast activity, dough rheology, pH, bake loss, residual sulphite, flavour impact and market rules |
| Sauces, condiments and dressings | Colour and flavour protection, oxygen reduction and yeast/mould control in selected acidic systems | pH, oil phase, vinegar, sugar, salt, preservatives, free sulphite, heat process, emulsion stability and declaration |
| Cheese and dairy-related systems | Only for highly specific permitted applications; not a general dairy preservative | Milk protein interaction, starter culture impact, pH, sulphite declaration, local dairy standards and customer policy |
| Meat processing | Potential antioxidant or colour-related review only where local rules permit; not a substitute for nitrite/nitrate curing systems | Product category, sulphite restrictions, cured-meat standards, pH, redox effects, residual sulphite, labelling and sensory impact |
| Dehydrated foods and dry mixes | Colour protection and oxidative stability in selected dry products or rehydrated systems | Moisture, water activity, particle distribution, rehydration behaviour, SO2 release, packaging barrier and shelf-life testing |
Quality and specification parameters
For industrial purchasing, Calcium Sulphite should be compared by active sulphite contribution, purity, impurity profile, solubility behaviour and regulatory documentation. A technically suitable grade should deliver the intended preservative or antioxidant effect without unacceptable insoluble residue, oxidation to sulphate, heavy-metal concerns, dosing inconsistency, sensory impact or compliance gaps.
| Specification area | What to request | Why it matters |
|---|---|---|
| Regulatory identity | E226 / INS 226 confirmation, CAS number, chemical identity and destination-market compliance note | Confirms correct sulphite additive identity and avoids non-food or technical-grade material |
| Assay | Calcium sulphite assay, analytical method and acceptance range | Primary basis for supplier comparison and dosage calculation |
| SO2-equivalent value | Declared sulphur dioxide equivalent or calculation basis | Critical for comparing sulphite salts, setting use level and checking label thresholds |
| Sulphite content | Available sulphite, free sulphite or total sulphite method where relevant | Helps predict real preservative and antioxidant performance |
| Hydrate form | Anhydrous, hemihydrate, tetrahydrate or supplier-declared hydrate form | Changes assay, molar mass, water content and dosage calculations |
| Sulphate impurity | Calcium sulphate or sulphate content and oxidation-related limits | Indicates oxidation during production or storage and reduces active sulphite value |
| Moisture | Moisture, loss on drying or water content | Affects assay, flowability, caking, oxidation and shelf life |
| Solubility and dispersion | Solubility behaviour, insoluble matter and application guidance | Important because Calcium Sulphite may release available sulphite differently than more soluble salts |
| Particle size | Mesh size, D10/D50/D90 where available, fines and sieve residue | Affects dosing, dispersion, reaction rate, dusting and premix uniformity |
| pH and alkalinity/acidity | pH of suspension or solution, alkalinity and related specification limits | Influences formulation compatibility and sulphite chemistry |
| Calcium content | Calcium content and analytical method | Important for mineral contribution, precipitation risk and identity confirmation |
| Contaminants | Heavy metals, lead, arsenic, cadmium, mercury, iron, chloride and other impurities | Supports food-grade approval, export compliance and customer audit requirements |
| Microbiology | Microbiological specification where required by customer or application | Relevant for high-care foods, dry blends and customer-specific quality programs |
| Compliance | Food-grade declaration, sulphite/allergen declaration, GMO statement, gluten statement, halal/kosher if required | Reduces regulatory, customer and label-approval delays |
| Traceability | Manufacturer, production site, country of origin, batch number, production date, retest date and shelf life | Enables supplier qualification, recall readiness and audit-trail control |
Formulation and plant-trial checklist
- Target function: define whether Calcium Sulphite is needed for oxygen scavenging, anti-browning, microbial stability, yeast inhibition, mould control, colour protection or redox adjustment.
- SO2-equivalent calculation: convert proposed dosage into sulphur dioxide equivalent and compare against legal and customer limits.
- Grade comparison: compare Calcium Sulphite with sodium metabisulphite, potassium metabisulphite and other sulphite sources on an active sulphite basis.
- pH testing: validate efficacy at the actual finished-product pH because sulphite antimicrobial performance is pH-dependent.
- Solubility check: confirm dispersion and available sulphite release in the real product matrix.
- Residual analysis: measure free and total sulphite where legal limits, label thresholds or customer requirements apply.
- Sensory review: check sulphurous odour, bitterness, mineral notes, flavour masking and interaction with aroma compounds.
- Process validation: test heat exposure, filling, filtration, holding, drying, packaging and shelf-life storage.
- Label review: confirm sulphite declaration, sensitivity-related statements and destination-market wording before launch.
- Cost-in-use: compare suppliers by active SO2 contribution, dosage, yield, defects, stability, documentation and landed cost.
Comparison with related preservative and sulphite options
Calcium Sulphite is part of a wider sulphite and preservative toolbox. The right choice depends on solubility, active SO2 contribution, product pH, cation restrictions, label strategy, sensory impact, customer policy and destination-market approval.
| Option | Typical reason to compare | Industrial note |
|---|---|---|
| Calcium Sulphite / E226 | Sulphite preservative and reducing function with calcium salt identity | Lower solubility can affect use route; confirm available sulphite in the application |
| Sodium Sulphite / E221 | More soluble sulphite source for selected antioxidant or preservative systems | Adds sodium and may be easier to dose in aqueous systems |
| Sodium Hydrogen Sulphite / E222 | Bisulphite function and stronger acidity-related sulphite chemistry in some systems | Compare pH impact, SO2 equivalent and handling requirements |
| Sodium Metabisulphite / E223 | Concentrated sulphite source widely used for antioxidant and preservative functions | High active SO2 equivalent; requires careful dosing and label review |
| Potassium Metabisulphite / E224 | Sulphite source often reviewed when sodium contribution is undesirable | Useful in some beverage and wine-style systems; potassium contribution must be considered |
| Potassium Sulphite / E225 | Alternative sulphite salt with potassium contribution | Market availability and permitted uses should be verified |
| Calcium Hydrogen Sulphite / E227 | Calcium bisulphite-type chemistry in selected systems | Not interchangeable without SO2-equivalent and pH-impact review |
| Potassium Hydrogen Sulphite / E228 | Bisulphite function with potassium contribution | Check permitted use, pH effect, sensory impact and final label declaration |
| Sorbates, benzoates or propionates | Alternative preservative systems for yeast, mould or bacterial control | Different antimicrobial spectrum, pH dependence, label status and sensory profile |
Process integration guidance
Calcium Sulphite should be added through a controlled dosing and validation process. Because its solubility and available sulphite release can be different from more soluble sulphite salts, the addition method should be confirmed by plant trials. The best addition point depends on pH, mixing, oxygen exposure, filtration, heat process and whether the target is free sulphite, total sulphite or oxygen-scavenging performance.
Powder and granule handling
- Use accurate weighing and avoid uncontrolled dusting during dosing
- Pre-disperse or slurry according to supplier guidance when direct addition causes uneven distribution
- Confirm mixing time, suspension stability and available sulphite release before production approval
- Protect opened packs from humidity and oxygen exposure to reduce caking and oxidation
- Record lot number, assay, dosage, addition time, pH and residual sulphite result
Aqueous and process-stream systems
- Confirm whether Calcium Sulphite is suitable for the intended liquid system or whether a more soluble sulphite is required
- Monitor pH, dissolved oxygen and free/total sulphite before and after addition
- Check sediment, turbidity, filtration load and mineral precipitation risk
- Validate shelf-life results under the final packaging oxygen barrier
- Confirm label and residual sulphite requirements before commercial release
Sulphite validation workflow
Industrial buyers should evaluate Calcium Sulphite through analytical and application trials. The approved purchasing specification should include both chemical acceptance criteria and performance-based checks in the target food system.
| Step | Recommended action |
|---|---|
| 1. Define shelf-life objective | Set the target: anti-browning, oxygen control, yeast inhibition, mould control, colour protection or combined preservative action |
| 2. Calculate SO2 equivalent | Convert dosage to sulphur dioxide equivalent and compare with permitted limits and label rules |
| 3. Confirm grade suitability | Check assay, solubility, hydrate form, sulphate impurity and food-grade documentation |
| 4. Run process trials | Apply the real pH, mixing, heat treatment, filtration, packaging and storage conditions |
| 5. Measure residuals | Test free sulphite, total sulphite, dissolved oxygen, colour, microbial load and sensory impact |
| 6. Approve label route | Confirm sulphite declaration, allergen/sensitivity wording and destination-market documentation |
| 7. Lock specification | Approve assay, SO2-equivalent range, impurity limits, packaging and document package |
Handling, storage and warehouse control
Calcium Sulphite should be handled according to the supplier safety data sheet, food-safety plan and local workplace rules. Sulphite powders can produce irritating dust and may release sulphur dioxide under acidic conditions. Good storage protects active sulphite content, prevents moisture uptake and reduces oxidation to sulphate.
| Control point | Recommended buyer action |
|---|---|
| Storage environment | Store in a clean, cool, dry and well-ventilated area according to supplier recommendations |
| Moisture protection | Keep bags or containers sealed until use and protect opened packs from humidity and condensation |
| Oxidation control | Minimise unnecessary air exposure and avoid long open-pack storage |
| Acid segregation | Store away from acids and incompatible materials that could release sulphur dioxide |
| Dust control | Use appropriate ventilation, closed handling and PPE according to SDS and site risk assessment |
| Odour control | Store away from odour-sensitive ingredients and packaging materials |
| Allergen/sulphite segregation | Manage sulphite-containing material according to site allergen or sensitivity-control procedures |
| Lot traceability | Record lot number, supplier COA, internal release status and expiry/retest date before use |
| Opened packaging | Define resealing, relabelling, retest and maximum-open-time procedures for each grade |
Packaging and logistics options
Packaging depends on supplier standard, physical form and order volume. Common industrial requests include laboratory samples, 1-5 kg trial packs, 10-25 kg bags, PE-lined multiwall bags, fibre drums, HDPE drums, moisture-barrier bags, palletised export packaging and full-container supply. For export projects, buyers should request pallet dimensions, net and gross weight, liner type, bag closure, batch coding system, shelf life, storage temperature, HS code guidance, document language and shipping marks before confirming the order.
Regulatory, allergen and label diligence
Calcium Sulphite should be managed as a regulated sulphite preservative according to the destination market. The buyer is responsible for verifying whether E226 / INS 226 is permitted in the destination market, whether the intended food category is covered, the maximum use level, the calculation method for sulphur dioxide equivalent, the residual sulphite limit, the label declaration and customer-specific restrictions.
Because sulphites are sensitivity-relevant additives in many jurisdictions, regulatory review should be completed before commercial purchase and before full-scale production. A grade that is acceptable for one fruit, beverage, sauce or dry-mix application may not be acceptable in another food category. Buyers should also verify whether the finished product is intended for infant foods, organic programs, clean-label products, school-food channels, export-only products or customer-specific “no sulphites added” policies.
Documents to request
- Product specification or technical data sheet with E226 / INS 226 confirmation and intended applications
- Certificate of analysis for available batch or representative lot
- Safety data sheet with handling, dust, acid-contact and sulphur dioxide release guidance
- Food-grade declaration and market-specific additive-use statement
- CAS, E-number, chemical identity, hydrate form and manufacturing-process statement where required
- Assay method, sulphite content and SO2-equivalent calculation data
- Sulphate impurity, moisture, pH, calcium content, insoluble matter and particle-size data
- Solubility or dispersion guidance for the intended application
- Heavy metals, lead, arsenic, cadmium, mercury, iron, chloride and impurity statements aligned with buyer requirements
- Microbiological specification where required by customer or application
- Allergen statement and sulphite declaration support for destination-market review
- GMO statement, gluten statement and cross-contact information
- Vegan/vegetarian, BSE/TSE, irradiation and nanomaterial statements where required
- Halal and kosher certificates when required by customer or destination market
- Origin statement, manufacturer information and traceability declaration
- Shelf-life, retest date and recommended storage conditions
- Label draft, packaging details, pallet configuration and net/gross weight
- Market-specific declarations required by the importing country
How to request this product
Send the product name, target grade, required assay, SO2-equivalent requirement, intended application, quantity, destination country, packaging preference, expected shipment date, delivery term and required documents. If you already purchase Calcium Sulphite, attach or describe your current specification, label, certificate of analysis, assay, SO2-equivalent value, dosage, hydrate form and supplier grade so alternatives can be compared accurately.
For faster technical review, include the finished-product category, pH, water activity, target shelf life, target microbial issue, oxygen exposure, heat process, packaging type, residual sulphite limit, label requirements, allergen/sulphite declaration requirements, destination-market rules, customer compliance requirements and whether trial samples are needed before bulk quotation.
Useful answers
What is Calcium Sulphite used for in food manufacturing?
Calcium Sulphite E226 is typically reviewed for sulphite preservative function, oxygen scavenging, anti-browning, colour protection, yeast inhibition, mould control and shelf-life design in selected applications. Exact suitability depends on grade, application, process, regulations and supplier documents.
Is Calcium Sulphite the same as calcium sulfate?
No. Calcium Sulphite is CaSO3 and is a sulphite additive, while calcium sulfate is CaSO4. Calcium Sulphite can oxidize toward sulfate over time or under unsuitable conditions, which is why sulphate impurity and active sulphite content should be checked.
Why does SO2-equivalent value matter?
Sulphite regulations and dosage comparisons are often managed on a sulphur dioxide equivalent basis. Two sulphite salts can have different active SO2-equivalent values, so buyers should compare active contribution rather than equal weight.
Is Calcium Sulphite highly soluble?
Calcium Sulphite has low water solubility compared with many sodium or potassium sulphite salts. Buyers should validate dispersion, available sulphite release and residual sulphite results in the real product matrix.
Which applications commonly evaluate this preservative?
Potential applications include selected fruit preparations, juices, ciders, beverage bases, fermentation systems, vegetable preparations, sauces, condiments, dry mixes, bakery-related systems and specific permitted shelf-life programs. Local food-category permission must be verified.
Which technical parameters should be compared between suppliers?
Buyers should compare E226 identity, assay, sulphite content, SO2-equivalent value, hydrate form, sulphate impurity, moisture, solubility, particle size, pH, calcium content, heavy metals, chloride, iron, microbiology where relevant, allergen/sulphite declaration, shelf life, packaging and compliance documents.
Can Global Food Additives source Calcium Sulphite?
Global Food Additives can review sourcing options for Calcium Sulphite according to target specification, assay, SO2-equivalent requirement, application, quantity, destination, packaging, shipment timing and required documentation.
Which documents should be requested?
Buyers commonly request a technical data sheet or specification, certificate of analysis, safety data sheet where applicable, food-grade declaration, E226 confirmation, assay method, SO2-equivalent data, sulphite declaration support, heavy-metal information, shelf-life information, label details and packing details.
Is this product permitted in every country?
No. Sulphite use depends on destination-market rules, food category, approved use, use level, residual sulphite limit, label requirements and buyer responsibility. Always verify regulatory status before commercial use.
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