# A Comparative Elemental Analysis of Espresso Coffee from Poland and Portugal

## TL;DR

This study compares the mineral content of espresso coffee from Poland and Portugal, finding that coffee contributes less to daily essential mineral intake but contains notable amounts of non-essential elements like nickel and lead.

## Contribution

The study provides a comparative elemental analysis of espresso coffee from two countries, highlighting differences in mineral content and potential contamination sources.

## Key findings

- Espresso coffee samples from Poland and Portugal showed similar but distinct mineral profiles.
- Coffee contributed less to essential element intake, while non-essential elements like Ni and Pb were present in significant amounts.
- Calcium and strontium in coffee were largely derived from the water used in preparation.

## Abstract

A comparative elemental analysis of espresso coffee from Poland and Portugal was carried out. Using an ICP-MS analytical procedure, samples collected from public cafes in Poland and Portugal (n = 60 and n = 44, respectively) were studied for their macromineral and trace element content. To evaluate the contribution of water to the final composition of the beverage, paired samples (i.e., collected from the same locations) of drinking water were also analysed. The mineral profile of the coffee espresso samples was quite similar: Mg > P > Ca > Rb > Mn > B > Zn > Cu > Sr > Ba > Ni > Pb > Cs > Mo > Sn > Cd > Sb > Tl for samples from Poland and Mg > P > Ca > Rb > B > Mn > Zn > Sr > Cu > Ni > Ba > Cs > Pb > Mo > Sn > Sb > Cd > Tl for samples from Portugal. For most of the elements, the espresso samples showed much higher levels than the water used in its preparation. The two most notable exceptions were Ca and Sr, where the elements present in the coffee came mainly from the water. The contribution of coffee espressos to the daily intake of essential elements seems to be reduced. Other non-essential elements like Ni (median = 81.0 µg/L and 86.8 µg/L for Polish and Portuguese espresso, respectively) and Pb (median = 14.3 µg/L and 4.43 µg/L, respectively) were observed in significant amounts in the coffee espresso samples analysed in this study. These elements have been shown to leach from coffee machines in other studies. More studies are necessary to confirm these results.