Risk assessment of coffees of different qualities and degrees of roasting

Abstract

During the coffee beans roasting process, occurs the formation of polycyclic aromatic hydrocarbons, which are associated with the incidence of cancer in humans. This study aimed to evaluate the influence of coffee bean quality and roasting degree regarding mutagenicity, cytotoxicity and genotoxicity. Six samples of coffee drink made with roasted and ground Coffea arabica beans from different qualities and roast degrees were used after freeze-drying. Both commercial and special quality grains suffered light, medium and dark roasting. According to the Salmonella/microsome assay, the highest concentration of commercial grain sample (dark roast) significantly increased the number of revertants of the TA98 strain in the absence of metabolization. All the samples induced cytotoxicity to HepG2 cells. These effects can be ranked in the following order from most to least toxic: medium roast – special grain > light roast – special grain > dark roast – commercial grain > dark roast – special grain > light roast – commercial grain > medium roast – commercial grain. None of the samples induced genotoxicity in HepG2 cells. Our findings show that the harmful effects of coffee depend not only on the degree of roasting but also on the grain quality.