Determination of heavy metals in the roasted and ground coffee beans and brew

摘要

Some compounds present in coffee beans can affect consumer health. The present study determines the content of heavy metal in coffee cultivated in the Cerrado Mineiro region (Alto Paranaíba – MG, Brazil), to compare the values found with the legal standards and check how these metals are extracted from the respective infusions. Fifty samples of coffee beans were analyzed, taken from the Alto Paranaíba region, MG, Brazil. Determination and quantification were done by recording the values from the atomic absorption spectrophotometer for the metals mentioned: cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn). The Cr concentrations presented earlier the limit allowed by law in 66% of the coffee samples. And 74% of the samples contained Pb in higher than permissible concentrations. For all the infusions, the metals evaluated were found in lower concentrations and were less significant with respect to the maximum permissible daily intake, except for Pb were quantified very high levels. Only seven of the 50 coffee samples revealed results with levels that were quantified to be within the legally stipulated standards. The Pb and Cr metals were found to have the highest percentage of leaching in the coffee infusions.