Recent progress in sugar colourants: GC-MS studies and extraction techniques

The study of colour and colour precursors in cane sugar has been an important research area at Sugar Processing Research Institute for many years. Previous studies on isolating colourant precursors have relied on various liquid-liquid extraction procedures, time consuming methods requiring large amounts of sample and solvent. Four methods were examined for the identification of raw sugar colourants: Micro-extraction cartridges containing either strong anion exchange resin (SAX) or C-18, Empore-SDB membranes, liquid-liquid extraction, and methanol/ethyl acetate extraction of crystalline raw sugar. Of these methods, SAX and methanol/ethyl acetate gave the most useful information. Colourants and colourant precursors in raw sugars from various sources were examined by gas chromatography and mass spectrometry. Phenolic acids as well as sugar degradation products were observed.