Determining the geographic origin of coffee beans is more challenging with roasted coffee beans, and is useful if it can be performed on the product available to the consumer. US researchers analysed the concentrations of 44 trace elements in 53 samples of roasted Arabica coffee beans (Coffea arabica) from 21 different countries. Although trace elements are not volatilised at roasting temperatures, the absolute elemental concentrations of coffee beans vary through different degrees of roasting (from green through dark roasts). The study analysed trace element ratios to evaluate concentration-related differences among beans from different origins. By comparing the distributions of 1892 element ratios for each of the countries, the study demonstrated that many of the world’s coffee-producing regions can be distinguished from other regions of the world on the basis of element ratios.
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