Activated Carbon-Mediated Decolourisation in Glucose Isomerisation to Obtain High-Purity Fructose - A Preliminary Study

The caramelisation process, involving sugar breakdown at elevated temperatures, produces brown-coloured compounds known as caramel compounds, contributing to both colour and flavour. This study addresses discolouration in carbohydrate conversion utilizing activated carbon (AC) during the glucose isomerisation into fructose, catalysed by the tertiary amine; N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA). Powder-like (G-135-ID1000) and particle-like (G-306-4070) AC were introduced to the reaction medium to remove brown colour while preserving carbohydrate quantity. The AC-treated samples underwent analysis using high-performance liquid chromatography (HPLC) and UV-visible spectrophotometry. Successful adsorption of coloured byproducts onto the AC was indicated by the resulting colourless solution. HPLC analysis revealed nearly unchanged concentrations of glucose, fructose and mannose, indicating selective removal of undesired coloured compounds by AC. The UV-visible spectrum of the reacted glucose sample shifted leftward after purification, confirming the effective removal of absorbance peaks within the 260-380 nm range. This study presents a promising approach to enhance the visual and compositional qualities of glucose isomerisation reactions catalysed by DMAPMA. AC as a purification agent effectively addresses undesirable colouration, offering a pathway for developing high-quality products with improved characteristics for diverse applications in the food and industrial sectors.