Analytical Raman spectroscopic study of cacao seeds and their chemical extracts

A Raman spectroscopic study of cacao seeds and their extracts has been successful in the identification of biomarker bands for theobromine, a member of the caffeine group of alkaloids. Unlike caffeine detected in guarana, the spectral signatures of theobromine suggest that it occurs as the free base in cacao. No theophylline or caffeine alkaloids were detected in cacao. Raman spectroscopic monitoring of the heptane and ethyl acetate organic extracts of pulverised cacao seeds demonstrates the removal of the fatty and waxy components whereas the methanol extract is found to remove and concentrate the highly coloured aromatic polyphenolic compounds. The theobromine alkaloid is still detectable in the solid residues from the extractions. This study suggests that Raman spectroscopic monitoring of cacao seed processing should be investigated further for the purposes of industrial process analytical control.