Aluminium coffee percolators as a source of dietary aluminium.

The aluminium content of coffee brewed and stored in aluminium percolators was measured using atomic absorption spectrometry. Brewing in a new aluminium pot added 0.88 (immediately after brewing ) to 1.18 mg aluminium (after a further 12-hr storage in the pot and reheating ) to each cup of coffee. Percolators which had been used repeatedly were less susceptible to mobilization of aluminium by coffee, and brewing in these increased the aluminium content of each cup of coffee by 0.40 mg immediately after brewing and by 0.58 mg after storage for 12 hr in the pot and reheating . The aluminium content of the ground coffee beans used in this work was relatively high (51.8 ppm). To demonstrate that the bulk of the aluminium measured in the percolated coffee samples were dissolved aluminium and was not part of the aluminium associated with the ground coffee, the dialysable aluminium was measured in some samples of coffee percolated in a new aluminium pot. These data indicate that 61% of the aluminium in the percolated coffee was dialysable immediately after brewing . Samples that were stored in a new aluminium percolator and reheated to 96 degrees C contained 75% dialysable aluminium. Although the levels of aluminium in percolated coffee have been measured, the bioavailability of the aluminium ingested in this way has yet to be determined.