The suitability of the simplified method of the analysis of coffee infusions on the content of Ca, Cu, Fe, Mg, Mn and Zn and the study of the effect of preparation conditions on the leachability of elements into the coffee brew

Content of potentially toxic elements (PTEs) in coffee and coffee-based products: a meta-analysis study, Systematic review, and health risk assessment

Coffee is the most popular beverage after water in the world, which has an important role in health as a result of various minerals and vitamins but it may be pollution source of potentially toxic elements (PTEs) that can threate the health. Thus, the current study intended to detect the level of PTEs such as Cadmium (Cd), Copper (Cu), Lead (Pb), Nickel (Ni), Znc (Zn) and Iron (Fe), in various coffee and coffee-based products (powder, ground, processed, infusion and bean). Considering the databases of Scopus, Google scholar, PubMed, and Web of Science, the concentration of PTEs in coffee and coffee-based products was retrieved and meta-analyzed. Additionally, the non-carcinogenic risks in terms of total hazard quotient (TTHQ) were assessed using Monte Carlo simulated (MCS) model. According to the findings of 23 articles, the ranking of metal concentration in different coffees was Fe > Zn > Cu> Ni > Pb > Cd in powder, Fe > Cu > Zn> Ni in ground, Fe > Zn > Ni> Cu> Pb > Cd in processed and infusion and Fe > Zn > Ni> Cs > Pb in bean. Moreover, based on WHO regions, the highest concentrations of Cd and Pb (0.742 mg/kg) were related to the South-East Asia Region (SEARO) and European region (EURO) respectively. However, the highest concentrations of Fe (81.161 mg/kg), Zn (33.392 mg/kg), Cu (9.408 mg/kg), and Ni (18.064 mg/kg) were related to Pan American health organization (PAHO), PAHO, PAHO and Eastern Mediterranean Region (EMRO), respectively. On the other hand, the risk pattern was different in different countries. Moreover, consumers in some countries were not at significant non-carcinogenic risks because of ingestion of PTEs via coffee and consumption of coffee-based products.

Assessment on Solubility and Solid Phase Chemical Fractionation of Manganese in Hot Infusions of Green and Roasted Mate

A solid phase chemical fractionation (SPCF) of the Mn in hot infusions prepared from commercial samples of roasted (RM) and green mate (GM) using a chelating resin Chelex 100 (NH4+ form) was performed to assess the relative lability of this essential trace element (ETE). In addition, total Mn contents in the RM and GM samples and their infusions were determined by flame atomic absorption spectrometry. Total polyphenol (TP) contents and the presence of soluble melanoidins (SM) were correlated with the Mn solubility in the RM and GM infusions. From the SPCF study, it was possible to observe that the soluble Mn forms in the mate infusions were essentially associated with relatively noninert chemical species (98.4-99.7%), suggesting that they may be potentially bioavailable. In addition, the soluble Mn contents in the GM infusions were 20.5% higher than those found in the RM. Mn solubility in the (RM) infusions was highly and directly correlated (r = 0.99) with the soluble TP, while in the GM infusions, it was high and inversely correlated with soluble TP (r =  -0.87). On the other hand, Mn solubility in the RM and GM infusions was weakly correlated with the SM. It should be stressed that GM infusions can contribute with 57 and 44% more than the RM infusions to the recommended adequate intake of Mn established for females and males, respectively. Moreover, this work is the first to evaluate and compare the relative lability of Mn and its solubility in the RM and GM infusions.

Medium Roasting and Brewing Methods Differentially Modulate Global Metabolites, Lipids, Biogenic Amines, Minerals, and Antioxidant Capacity of Hawai'i-Grown Coffee (Coffea arabica)

In the United States, besides the US territory Puerto Rico, Hawai'i is the only state that grows commercial coffee. In Hawai'i, coffee is the second most valuable agricultural commodity. Health benefits associated with moderate coffee consumption, including its antioxidant capacity, have been correlated to its bioactive components. Post-harvest techniques, coffee variety, degree of roasting, and brewing methods significantly impact the metabolites, lipids, minerals, and/or antioxidant capacity of brewed coffees. The goal of our study was to understand the impact of roasting and brewing methods on metabolites, lipids, biogenic amines, minerals, and antioxidant capacity of two Hawai'i-grown coffee (Coffea arabica) varieties, "Kona Typica" and "Yellow Catuai". Our results indicated that both roasting and coffee variety significantly modulated several metabolites, lipids, and biogenic amines of the coffee brews. Furthermore, regardless of coffee variety, the antioxidant capacity of roasted coffee brews was higher in cold brews. Similarly, total minerals were higher in "Kona Typica" cold brews followed by "Yellow Catuai" cold brews. Hawai'i-grown coffees are considered "specialty coffees" since they are grown in unique volcanic soils and tropical microclimates with unique flavors. Our studies indicate that both Hawai'i-grown coffees contain several health-promoting components. However, future studies are warranted to compare Hawai'i-grown coffees with other popular brand coffees and their health benefits in vivo.

Re-evaluation of the existing health-based guidance values for copper and exposure assessment from all sources

Copper is an essential micronutrient and also a regulated product used in organic and in conventional farming pest management. Both deficiency and excessive exposure to copper can have adverse health effects. In this Scientific Opinion, the EFSA 2021 harmonised approach for establishing health-based guidance values (HBGVs) for substances that are regulated products and also nutrients was used to resolve the divergent existing HBGVs for copper. The tightly regulated homeostasis prevents toxicity manifestation in the short term, but the development of chronic copper toxicity is dependent on copper homeostasis and its tissue retention. Evidence from Wilson disease suggests that hepatic retention is indicative of potential future and possibly sudden onset of copper toxicity under conditions of continuous intake. Hence, emphasis was placed on copper retention as an early marker of potential adverse effects. The relationships between (a) chronic copper exposure and its retention in the body, particularly the liver, and (b) hepatic copper concentrations and evidence of toxicity were examined. The Scientific Committee (SC) concludes that no retention of copper is expected to occur with intake of 5 mg/day and established an Acceptable Daily Intake (ADI) of 0.07 mg/kg bw. A refined dietary exposure assessment was performed, assessing contribution from dietary and non-dietary sources. Background copper levels are a significant source of copper. The contribution of copper from its use as plant protection product (PPP), food and feed additives or fertilisers is negligible. The use of copper in fertilisers or PPPs contributes to copper accumulation in soil. Infant formula and follow-on formula are important contributors to dietary exposure of copper in infants and toddlers. Contribution from non-oral sources is negligible. Dietary exposure to total copper does not exceed the HBGV in adolescents, adults, elderly and the very elderly. Neither hepatic copper retention nor adverse effects are expected to occur from the estimated copper exposure in children due to higher nutrient requirements related to growth.

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.

Quality of Commercial Coffees: Heavy Metal and Ash Contents

This study aimed to quantify the ash content and to determine the concentration of heavy metals in roasted ground coffee and their respective infusions. The ash content was determined by incineration of the samples, and the quantification of heavy metals was performed by flame atomic absorption spectrophotometry for the following metals: cadmium, lead, copper, chromium, nickel, and zinc. According to the ash analysis, 15% of the roasted ground coffee samples were within the standards established by the legislation of the state of São Paulo, which has set an ash content of below 5%. In the roasted ground coffee samples, the Cd, Cu, Ni, and Zn contents did not exceed the limit established by Brazilian legislation. In several samples, both Pb and Cr were found in high levels, exceeding the limits established by Brazilian legislation. In the infusions of roasted ground coffee, the Cd, Cu, Cr, and Ni contents were below the detection limit of the equipment. Zn was found in all infusions and Pb was only detected in seven coffee infusion samples. Overall, the concentrations of heavy metals found in the commercially roasted ground coffee and their respective infusions are lower than the limits recommended by the official inspection agencies and, thus, are suitable for consumption.

Preconcentration of Zn, Cu, and Ni Ions from Coffee Infusions via 8-Hydroxyquinoline Complexes on Graphene Prior to Energy Dispersive X-ray Fluorescence Spectrometry Determination

A simple and effective preconcentration procedure based on dispersive micro solid-phase extraction prior to energy dispersive X-ray fluorescence spectrometric (EDXRF) determination of trace amounts of Ni, Cu, and Zn in coffee infusions was proposed. The method is based on the adsorption of 8-hydroxyquinoline metal complexes on micro amounts of graphene nanoparticles. In order to optimize adsorption process, the influence of some parameters such as pH, graphene mass, concentration of 8-hydroxyquinoline (8-HQ) and Triton X-100, sample volume, and sorption time were examined. At optimal preconcentration conditions, calibration curves were linear from 1 to 150 ng mL^-1 for Ni and Cu and from 1 to 200 ng mL^-1 for Zn. The recoveries of the metal ions were in the 95-98% range with the precision lower than 4.6%. The obtained detection limits were 0.08 ng mL^-1 for Ni and 0.09 ng mL^-1 for Cu and Zn. The proposed method was successfully applied to determination of Ni, Cu, and Zn in coffee infusions. Accuracy and repeatability of the proposed procedure were confirmed by the standard addition method and compared to the results obtained by ICP-OES technique.

Elemental composition of green coffee and its contribution to dietary intake

The concentration of twenty-seven elements (Li, Be, B, Mg, Al, P, K, Ca, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Sn, Sb, Ba, Hg, Pb, Bi, Th, and U) in green coffee samples and their infusions were determined by using inductively coupled plasma-mass spectrometry (ICP-MS). Prior to analysis, green coffee samples were prepared by microwave digestion, while infusions were analyzed without any pre-treatment. The accuracy and precision of the proposed methods were verified by recovery experiments. Considering samples; K, Cu, and Al had the highest mean concentrations with 6714.5μgg(-1), 12.1μgg(-1), and 25.9μgg(-1) among major, trace and toxic elements, respectively. The impact of brewing type on leachability of elements was also studied and the results outlined that mean leachability of elements to Turkish coffee were greater than to mud coffee. Furthermore, dietary element intakes through green coffee consumption were also estimated. This is the first study presenting wide range of elements in green coffee brews and calculating dietary intakes.

A simplified determination of total concentrations of Ca, Fe, Mg and Mn in addition to their bioaccessible fraction in popular instant coffee brews

A direct analysis of instant coffee brews with HR-CS-FAAS spectrometry to determine the total Ca, Fe, Mg and Mn content has been developed and validated. The proposed method is simple and fast; it delivers good analytical performance; its accuracy being within -3% to 3%, its precision--2-3% and detection limits--0.03, 0.04, 0.004 and 0.01 mg l(-1) for Ca, Fe, Mg and Mn, respectively. In addition, Ca, Fe, Mg and Mn bioaccessibility in instant coffee brews was measured by means of the in vitro gastrointestinal digestion with the use of simulated gastric and intestinal juice solutions. Absorption of metals in intestinal villi was simulated by means of ultrafiltration over semi-permeable membrane with a molecular weight cut-off of 5 kDa. Ca, Fe, Mg and Mn concentrations in permeates of instant coffee gastrointestinal incubates were measured with HR-CS-FAA spectrometry.

The content of Ca, Cu, Fe, Mg and Mn and antioxidant activity of green coffee brews

A simple and fast method of the analysis of green coffee infusions was developed to measure total concentrations of Ca, Cu, Fe, Mg and Mn by high resolution-continuum source flame atomic absorption spectrometry. The precision of the method was within 1-8%, while the accuracy was within -1% to 2%. The method was used to the analysis of infusions of twelve green coffees of different geographical origin. It was found that Ca and Mg were leached the easiest, i.e., on average 75% and 70%, respectively. As compared to the mug coffee preparation, the rate of the extraction of elements was increased when infusions were prepared using dripper or Turkish coffee preparation methods. Additionally, it was established that the antioxidant activity of green coffee infusions prepared using the mug coffee preparation was high, 75% on average, and positively correlated with the total content of phenolic compounds and the concentration of Ca in the brew.

Simplified sample treatment for the determination of total concentrations and chemical fractionation forms of Ca, Fe, Mg and Mn in soluble coffees

A simpler, and faster than wet digestion, sample treatment was proposed prior to determination of total concentrations for selected macro- (Ca, Mg) and microelements (Fe, Mn) in soluble coffees by flame atomic absorption spectrometry. Samples were dissolved in water and acidified with HNO3. Precision was in the range 1-4% and accuracy was better than 2.5%. The method was used in analysis of 18 soluble coffees available on the Polish market. Chemical fractionation patterns for Ca, Fe, Mg and Mn in soluble coffees, as consumed, using a two-column solid-phase extraction method, determined Ca, Mg and Mn were present predominantly as cations (80-93% of total content). This suggests these elements are likely to be highly bioaccessible.