Can impurities from soil-contaminated coffees reach the cup?

Coffee Infusions: Can They Be a Source of Microelements with Antioxidant Properties?

Coffee is a beverage that is very popular all over the world. Its pro-health effect has been demonstrated in many publications. This drink can counteract the effects of oxidative stress thanks to its antioxidant properties. The aim of this study was to collect data on the content of microelements with antioxidant activity (manganese, zinc, copper, iron) in coffee infusions, taking into account various factors. The study considered publications from the years 2000–2020 found in Google Scholar and PubMed databases. It was noted that coffee can provide up to 13.7% of manganese requirements per serving, up to 4.0% and 3.1% of zinc requirements for women and men, up to 2.7% and 2.1% of copper requirements for women and men, and up to 0.4% and 0.6% of iron requirements for women and men. Coffee infusions can also be a source of fluoride (up to 2.5%), chromium (up to 0.4% of daily intake for women and 0.2% for men), and cobalt (up to 0.1%). There are no data in the literature regarding the content of selenium in coffee infusions. The origin of coffee beans and the type of water used (especially regarding fluoride) may have an impact on the content of minerals in infusions. The brewing method does not seem to play an important role. As it is a very popular beverage, coffee can additionally enrich the diet with such micronutrients as manganese, zinc, and copper. This seems beneficial due to their antioxidant properties, however the bioavailability of these elements of coffee should be taken into account. It seems necessary to carry out more research in this area.

Coffee Brews: Are They a Source of Macroelements in Human Nutrition?

Coffee brews, made by pouring water on coffee grounds or brewing in an espresso machine, are among the most popular beverages. The aim of this study was to summarize data on the content of macroelements (sodium, potassium, calcium, magnesium, and phosphorus) in coffee brews prepared with different methods, as well as to review the factors influencing the content of the elements. Studies from 2000 to 2020, published in the PubMed and Google Scholar databases, were reviewed. Taking into account the results presented by the authors, we calculated that one portion of coffee brew can cover 7.5% or 6.4% (for women and men) and 6.6% of the daily requirement for magnesium and potassium, respectively. Coffee provides slightly lower amounts of phosphorus (up to 2.2%), sodium (up to 2.2%), and calcium (up to 0.7% of the daily requirement for women and 0.6% for men). If coffee is drunk in the quantity of three to four cups, it can be an important source of magnesium, considering the risk of magnesium deficiency in modern societies.

Elemental analysis of Brazilian coffee with ion beam techniques: From ground coffee to the final beverage

Brazilian coffee is well known worldwide due to its quality and richness in taste. The aim of the present study is to provide the elemental characterization of Brazilian coffee along different stages of the drip brewing process. To that end, samples from roasted ground coffee, spent coffee, paper filters and the final beverage were analyzed with one single ion beam technique, namely particle-induced X-ray emission (PIXE). In total, over 140 samples from 8 different Brazilian brands of ground coffee were analyzed. Large differences in some elemental concentrations were observed among different brands and among different batches of a single brand, which leads to high variances in the data. Concerning the beverage preparation, the analysis of the spent coffee shows that the transfer ratio from the ground coffee to the beverage differs for each element. Our results indicate that potassium and chlorine have the highest transfer ratio. Moreover, the concentration of rubidium is relatively high in drinking coffee. Finally, there is no influence of the elemental composition of paper filter in the preparation of drinking coffee.