New Grounds for Drinking Coffee
New information suggests that your morning cup of coffee may be a healthy part of a nutritious breakfast. Research by an international team of scientists published in the April 2000 issue of Human and Ecological Risk Assessment has shown that automatic drip coffee makers can remove up to 85% of both copper and lead in tap water. Team leader Herbert E. Allen, a professor of civil and environmental engineering at the University of Delaware in Newark, speculates that coffee grounds retain heavy metals through surface chelation, a chemical reaction in which metals form complexes with organic matter. After looking at ion exchange or adsorption as possible filtering mechanisms, Allen says that due to coffee's nature-coffee grounds having uncharged or negatively charged molecules-surface chelation most likely explains the large percentage of metals removed. Because dissolved heavy metals are positively charged, the metal ions bind strongly to the coffee, he says.
The study was conducted by Allen, graduate student Christopher Impellitterri, Michael McLaughlin of the division of soils at the Commonwealth Scientific and Industrial Research Organisation in Adelaide, Australia, and Gustavo Lagos, a scientist at the Pontificia Universidad Cat