Sugar and sweetener producers depend on activated carbon to deliver the colourless, odourless, high purity products their customers expect. Cane and beet sugar refineries, glucose syrup plants, fructose producers, and modern stevia and erythritol manufacturers all use activated carbon at one or more decolourisation stages. The technology is well established and economically attractive because it delivers a single step that removes colour, off odours, and trace organic impurities together. As an activated carbon manufacturer and supplier, SorbiTech provides food grade carbon engineered specifically for sweetener decolourisation duty.
How Activated Carbon Removes Colour from Sugar
Sugar liquor and sweetener syrups contain colour bodies that originate from raw material processing, thermal degradation during boiling, and Maillard reactions during refining. These colour bodies are large polycyclic organic molecules with characteristic absorbance in the visible spectrum. Activated carbon removes them by adsorption, with the molecules entering the carbon mesopores and being held inside the pore structure. Because colour bodies are large molecules, activated carbon for sugar service needs a high mesoporous content, which makes wood based and certain coal based grades the preferred raw materials for this application.
Cane Sugar Refining
Cane sugar refineries use powdered activated carbon in the decolourisation stage following clarification. The powder is mixed with the sugar liquor in agitated tanks for a defined contact time, then removed by filtration with the spent filter aid. This single use approach gives consistent quality and is the standard at most cane refineries worldwide. Typical dosing rates range from one tenth of a percent to half a percent by sugar weight, depending on the input colour load and the target finished sugar specification.
Beet Sugar and Glucose Plants
Beet sugar plants traditionally use granular activated carbon in fixed beds for decolourisation, although modern plants increasingly use ion exchange resin for primary colour removal followed by GAC polishing. The polishing step is critical for producing the high quality white sugar that meets ICUMSA colour specifications. Corn wet milling plants producing glucose and high fructose corn syrup use activated carbon for both colour and odour removal, polishing the syrup after enzymatic conversion and ion exchange demineralization. The same approach polishes the syrup before it reaches the downstream beverage industry and customers.
Selecting Activated Carbon for Sugar Service
The right grade depends on the molecular weight of the colour bodies, the syrup pH, and the target finished sugar specification. The methylene blue value is the most important parameter because it indicates the carbon’s mesoporous capacity for the larger colour body molecules. The iodine number is also relevant for trace organic removal. Acid washed grades with low ash and low iron content are preferred for high purity products, especially where the syrup is acidic or where any leached metals would affect colour stability of the final crystallised sugar.
Powdered carbon is used in batch decolourisation of sugar liquors, typically at 200 to 325 mesh nominal particle size for fast kinetics. Granular grades are used in fixed bed polishing service, sized to match the existing bed hydraulics and operating cycle.
SorbiTech Activated Carbon for Sugar Decolorization
SorbiTech supplies food grade powder activated carbon and granular activated carbon for cane sugar, beet sugar, glucose, fructose, and natural sweetener decolourisation. All grades meet the relevant food contact requirements and are supplied with full certificates of analysis on every batch. The technical team supports sugar producers with bench scale dose optimisation studies on real sugar liquor samples, allowing accurate forecasting of dosing rate and finished sugar quality before scale up. Contact SorbiTech to discuss your sugar or sweetener decolourisation requirements and the right grade for your liquor and target specification.