Evaluation of the Possible Effect of the Grinders Installed in Fully Automatic Espresso Coffee Machines on the Element Content in Brewed Coffees

Abstract

This investigation was aimed at evaluating whether the element release from the grinding systems installed in fully automatic coffee machines could cause their increase in coffee brews to become worrying. Thus, the content of 24 elements was determined by ICP-MS in roasted coffee beans ground in six fully automated machines, in two of which heavily used grinders were deliberately installed in order to evaluate the effect of their deterioration. These contents were compared with those found in the same type of roasted coffee beans hand-ground in an agate mortar. The content of the same elements in both spent coffee pucks, residual from either hand grinding or automatic grinding, and coffee drinks prepared with the assayed fully automatic machines fed with either automatically ground coffee beans or hand-ground coffee powder, were determined and compared with one another. The results showed only very small differences due to the grinding method adopted, which were largely lower than the standard deviations affecting our determinations.