HETEROCYCLIC COMPOUNDS IN MEDIUM ROASTED COFFEE HARVESTED FROM VARIOUS GEOGRAPHIC REGIONS

Abstract

The research is focused on GC-MS identification of heterocyclic compounds (HCCs) in commercially most accepted medium roasted specialty coffee beans from renowned harvesting sites from Africa and America and their precursors in green beans. Obtained GC-MS data showed the most abundant HCCs group in medium roasted coffee was furan derivates and pyrazine derivates, reaching an average of 24.17% in African samples, 22.27% in American samples, and 13.41% and 17.62%, respectively. Pyridine derivates reached similar concentrations, 5.02% in African and 5.27% in American samples. The least abundant group was pyrrole derivates, reaching only 2.79% in African and 1.91% in American samples. Pearson’s correlation proved weak positive correlations between all HCCs (furan derivates, pyrrole derivates, pyrazines derivates, and pyridine derivates) and volatiles hydrocarbons measured in green samples. Further correlation analysis proved the positive correlation between aldehydes, furanes, and pyrazines. However, Pearson’s correlation coefficient proved a weak correlation (0.273 – 0.455). ANOVA pointed out that after the roasting, only pyrazine derivates showed geographical dependence, suggesting there might be other precursors that need to be studied to better understand safety and quality issues from the perspective of origin and roasting of the commodity.