Espresso coffees, caffeine and chlorogenic acid intake: potential health implications.

摘要

HPLC analysis of 20 commercial espresso coffees revealed 6-fold differences in caffeine levels, a 17-fold range of caffeoylquinic acid contents, and 4-fold differences in the caffeoylquinic acid:caffeine ratio. These variations reflected differences in batch-to-batch bean composition, possible blending of arabica with robusta beans, as well as roasting and grinding procedures, but the predominant factor was likely to be the amount of beans used in the coffee-making/barista processes. The most caffeine in a single espresso was 322 mg and 3 contained >200 mg, exceeding the 200 mg day--1 upper limit recommended during pregnancy by the UK Food Standards Agency. Results suggest that the published assumption that a cup of strong coffee contains 50 mg caffeine may be misleading. Consumers at risk of toxicity, including pregnant women, children and those with liver disease, may unknowingly ingest excessive caffeine from a single cup of espresso coffee. As many coffee houses prepare larger vol. coffees, such as Latte and Cappuccino, by dilution of a single or double shot of expresso, further study on these products is warranted. New data are needed to provide informative labelling, with attention to bean variety, preparation and barista methods.