Beverages as a source of toxic trace element intake

Evaluation of Trace Elements in Coffee and Mixed Coffee Samples Using ICP-OES Method

This research examines the concentration of 10 trace elements including arsenic (As), lead (Pb), chromium (Cr), zinc (Zn), iron (Fe), cobalt (Co), cadmium (Cd), nickel (Ni), manganese (Mn), and aluminum (Al) from among 36 different samples of coffee (3 brands and 2 types of simple and instant) and mixed coffee (3 brands and 4 types of simple, creamy, chocolate and sugar free) collected from market of Iran's and analyzed by using ICP-OES (inductively coupled plasma-optical emission spectrometry). The recovery, limit of quantification (LOQ), and limit of detection (LOD) ranged from 93.4 to 103.1%, 0.06 to 7.22, and 0.018 to 2.166 µg/kg, respectively. The findings showed that the highest and lowest average concentrations were 498.72 ± 23.07 μg/kg (Fe) and 3.01 ± 1.30 μg/kg (As) in coffee and mixed coffee samples. Also, in all samples, the maximum concentration of trace elements was related to Fe (1353.61 µg/kg) and the minimum concentration was related to Al, As, Co, Cr, Ni, Pb, and Zn that were not detected (ND). The samples of mixed coffee had highest levels of trace elements compared to coffee samples. In coffee samples, type of instant coffee had highest levels of trace elements compared to simple coffee and mixed coffee samples. The type of creamy mixed coffee had highest levels of trace elements (except Ni and Cr) compared to other type of mixed coffee samples. Finally, trace elements were less than the standard levels of Iran and other countries (in all samples); therefore, it does not threaten Iranian consumers.

Probabilistic Risk Assessment of Metals, Acrylamide and Ochratoxin A in Instant Coffee from Brazil, Colombia, Mexico and Peru

This study analysed the probabilistic risk to consumers associated with the presence of iAs, Cd, Cr, Hg, Pb, acrylamide (AA) and ochratoxin A (OTA) in instant coffee from Brazil, Colombia, Mexico and Peru. The results found iAs to be the metal with the highest concentrations (3.50 × 10-2 to 6.00 × 10-2 mg/kg), closely followed by Pb (1.70 × 10-2 to 2.70 × 10-2 mg/kg) and Cr (5.00 × 10-3 to 1.00 × 10-2 mg/kg), although these differences were not significant between countries. Cd and Hg were not detected. Focusing on AA, the concentrations ranged from 1.77 × 10-1 mg/kg (Peru) to 4.77 × 10-1 mg/kg (Brazil), while OTA ranged from 1.32 × 10-3 (Peru) to 1.77 × 10-3 mg/kg (Brazil) with significant differences between countries in both cases. As regards risk, the hazard quotient and hazard index were less than 1, meaning that the consumption of instant coffee represents a low level of concern for non-genotoxic effects. The results of the combination of margin of exposure and probability of exceedance indicated that the non-genotoxic effects of Pb, AA and OTA pose no threat. However, the probability values of suffering cancer from iAs and AA (between 1 × 10-6 and 1 × 10-4) indicated a moderate risk and that management measures should be taken.

Sensitivity analyses informed by tests for bias in observational studies

In an observational study, the treatment received and the outcome exhibited may be associated in the absence of an effect caused by the treatment, even after controlling for observed covariates. Two tactics are common: (i) a test for unmeasured bias may be obtained using a secondary outcome for which the effect is known and (ii) a sensitivity analysis may explore the magnitude of unmeasured bias that would need to be present to explain the observed association as something other than an effect caused by the treatment. Can such a test for unmeasured bias inform the sensitivity analysis? If the test for bias does not discover evidence of unmeasured bias, then ask: Are conclusions therefore insensitive to larger unmeasured biases? Conversely, if the test for bias does find evidence of bias, then ask: What does that imply about sensitivity to biases? This problem is formulated in a new way as a convex quadratically constrained quadratic program and solved on a large scale using interior point methods by a modern solver. That is, a convex quadratic function of N variables is minimized subject to constraints on linear and convex quadratic functions of these variables. The quadratic function that is minimized is a statistic for the primary outcome that is a function of the unknown treatment assignment probabilities. The quadratic function that constrains this minimization is a statistic for subsidiary outcome that is also a function of these same unknown treatment assignment probabilities. In effect, the first statistic is minimized over a confidence set for the unknown treatment assignment probabilities supplied by the unaffected outcome. This process avoids the mistake of interpreting the failure to reject a hypothesis as support for the truth of that hypothesis. The method is illustrated by a study of the effects of light daily alcohol consumption on high-density lipoprotein (HDL) cholesterol levels. In this study, the method quickly optimizes a nonlinear function of N = 800 $N=800$ variables subject to linear and quadratic constraints. In the example, strong evidence of unmeasured bias is found using the subsidiary outcome, but, perhaps surprisingly, this finding makes the primary comparison insensitive to larger biases.

The role of dietary factors on blood lead concentration in children and adolescents - Results from the nationally representative German Environmental Survey 2014-2017 (GerES V)

In industrialized nations, human lead exposure has decreased significantly in recent decades. Nevertheless, due to its toxic effects, this heavy metal remains a public health concern with children and adolescents being particularly at risk. In Europe nowadays, oral intake via food and drinking water is the predominant exposure pathway for lead. The objective of the present study was to investigate the association between dietary factors and blood lead (PbB) level of 3- to 17-year-old children and adolescents living in Germany, using data from the fifth German Environmental Health Survey (GerES V) and the Child and Adolescent Health Survey (KiGGS Wave 2). GerES V and KiGGS Wave 2 are two national population-representative studies conducted between 2014 and 2017, including measurement of lead concentrations in blood from 720 children and adolescents aged 3-17 years (mean age = 10.21, SD age = 4.36). Using multiple linear regression, sociodemographic and environmental characteristics as well as dietary factors could be identified as significant exposure determinants of PbB concentrations. Lead intake via domestic tap water was the strongest predictor of elevated PbB levels with 27.6% (p-value< .001) higher concentrations of highest compared to none lead intake via tap water. Other foods which were found to be relevant to PbB levels were meat, fruit, and fruit juice. While meat or fruit consumption were each associated with about 13% (p-value < .05) lower PbB levels, fruit juice drinking was associated with up to 12.2% (p-value = .04) higher PbB levels. In conclusion, results indicate the importance of dietary habits for lead exposure in children and adolescents. To protect vulnerable groups, it is recommended that future research and lead-reducing measures pay more attention to dietary links.

Heavy Metals and Human Health: Possible Exposure Pathways and the Competition for Protein Binding Sites

Heavy metals enter the human body through the gastrointestinal tract, skin, or via inhalation. Toxic metals have proven to be a major threat to human health, mostly because of their ability to cause membrane and DNA damage, and to perturb protein function and enzyme activity. These metals disturb native proteins’ functions by binding to free thiols or other functional groups, catalyzing the oxidation of amino acid side chains, perturbing protein folding, and/or displacing essential metal ions in enzymes. The review shows the physiological and biochemical effects of selected toxic metals interactions with proteins and enzymes. As environmental contamination by heavy metals is one of the most significant global problems, some detoxification strategies are also mentioned.

Wine features related to safety and consumer health: an integrated perspective

This review presents a global view of the current situation of the scientific knowledge about aspects of wine with possible repercussions (positive or negative) on consumer health and wine safety. The presence in wine of some potential harmful compounds such as phytosanitary products, trace metal compounds, sulfites, and some toxics of microbial origin, such as ochratoxin A, ethyl carbamate, and biogenic amines, is discussed. The different strategies and alternative methodologies that are being carried out to reduce or to avoid the presence of these substances in wines are also discussed. In recent years much work has focused on establishing the scientific explanations for the positive biological effects of some wine compounds. In this review, we also examine the latest knowledge regarding wine and health, focusing on two types of compounds that have been related to the positive effects of moderate wine consumption, such as phenolic compounds and bioactive peptides.

Arsenic species and leaching characters in tea (Camellia sinensis)

Tea is one of the most popular non-alcoholic beverages consumed in the world. Arsenic including species totalling to 47 Chinese tea samples from 18 tea-producing provinces in China were analyzed. By simulating the infusion process, leaching characters, effects of extraction time and temperature on arsenic extraction were investigated. Total amount of arsenic in tea leaf samples was in the range below the detection limit to 4.81 microg/g. Leaching of arsenic was strongly affected by extraction time and temperature. Because arsenic leaching ability by hot water was low and most of the arsenic was left in tea leaf residues after infusion, the concentration of arsenic in tea infusion was low even when some original tea leaf samples contained high level of arsenic. The major species in tea infusion were inorganic arsenic form (arsenite As(III) and arsenate As(V)). Compared with the amount of arsenic in infusion, more organic arsenic species were found in the original tea leaf samples. The contents of extractable inorganic arsenic in tea leaf samples were in the range below the detection limit to 226 ng/g. Considering ingestion dose and assuming one person (60 kg body weight) consumes 10 g of Chinese tea per day, the maximum inorganic arsenic contribution from tea infusion is 2.26 microg, which is equal to 0.038 microg/kg/d excluding water contribution. This value only accounts for 1.8% of provisional tolerable weekly intake (PTWI) (2.1 microg/kg/d) recommended by the Food and Agriculture Organization/World Health Organization [FAO/WHO, 1989. Evaluation of certain food additives and contaminants. Thirty-third Report of the Joint FAO/WHO Expert Committee on Food Additives. WHO Technical Report Series No. 776, Geneva, World Health Organization].

On the determination of lead in wine by electrothermal atomic absorption spectrometry

The parameters of analytical procedures developed for direct ETAAS determination of Pb in wine are discussed. Atomic absorption spectrometers based on transversal and longitudinal Zeeman effect, wall and integrated platform atomization with two main approaches: (i) measurements in the presence of modifier and (ii) measurements without using any modifier are compared. The optimal temperature programs are defined according to the pre-treatment and atomization curves constructed in the presence of different types of wines. For all investigated instrumental systems, 1:1 dilution of wine sample with 0.2 mol L−1 HNO3 is recommended. Matrix interferences observed, call for standard addition calibration method for Pb quantification in wines. The detection limit (3σ) achieved for wine diluted in the ratio of 1:1 varied from 0.8 to 1.9 μg L−1 depending on the instrument used. The relative standard deviation for the concentration range of 10 to 80 μg L−1 Pb in wine is typically between 4–8%. The accuracy of the analytical procedures recommended was confirmed by comparing the results obtained with those found for wine samples previously digested with HNO3-H2O2 mixture, by added/found method and by parallel analysis using different instruments. A total of 66 wine samples from different regions of Macedonia were analyzed.

Arsenic in various foods: Cumulative data

Data for the arsenic content in various foods were collated. The number of collected values was about 2500 columns, which enables an estimation of the range of arsenic contents in each food group. Data were categorized into six groups (crops, milk/meat/egg, fish, algae, seafood, others) and expressed as a percentile graph. In addition, the inorganic arsenic ratio of each food group was estimated. This approach enabled the authors to understand the arsenic contents of some food groups at a glance. The intake of inorganic arsenic seems to be mostly from seafood. The contribution from other categories of food is small.

Determination of lead in wine by hydride generation atomic fluorescence spectrometry in the presence of hexacyanoferrate(III)

A rapid, accurate, and precise method is described for the determination of Pb in wine using continuous-flow hydride generation atomic fluorescence spectrometry (CF-HGAFS). Sample pretreatment consists of ten-fold dilution of wine followed by direct plumbane generation in the presence of 0.1 mol L(-1) HCl and 1% m/v K(3)[Fe(CN)(6)] with 1% m/v NaBH(4) as reducing agent. An aqueous standard calibration curve is recommended for Pb quantification in wine sample. The method provides a limit of detection and a limit of quantification of 0.3 microg L(-1) and 1 microg L(-1), respectively. The relative standard deviation varies between 2-6% (within-run) and 4-11% (between-run) at 3-30 microg L(-1) Pb levels in wine. Good agreement has been demonstrated between results obtained by CF-HGAFS and direct electrothermal atomic absorption spectrometry in analyses of red and white wines within the concentration range of 9.2-25.8 microg L(-1) Pb.

Mass spectrometry in grape and wine chemistry. Part II: The consumer protection

Controls in food industry are fundamental to protect the consumer health. For products of high quality, warranty of origin and identity is required and analytical control is very important to prevent frauds. In this article, the "state of art" of mass spectrometry in enological chemistry as a consumer safety contribute is reported. Gas chromatography-mass spectrometry (GC/MS) and liquid-chromatography-mass spectrometry (LC/MS) methods have been developed to determine pesticides, ethyl carbamate, and compounds from the yeast and bacterial metabolism in wine. The presence of pesticides in wine is mainly linked to the use of dicarboxyimide fungicides on vineyard shortly before the harvest to prevent the Botrytis cinerea attack of grape. Pesticide residues are regulated at maximum residue limits in grape of low ppm levels, but significantly lower levels in wine have to be detected, and mass spectrometry offers effective and sensitive methods. Moreover, mass spectrometry represent an advantageous alternative to the radioactive-source-containing electron capture detector commonly used in GC analysis of pesticides. Analysis of ochratoxin A (OTA) in wine by LC/MS and multiple mass spectrometry (MS/MS) permits to confirm the toxin presence without the use of expensive immunoaffinity columns, or time and solvent consuming sample derivatization procedures. Inductively coupled plasma-mass spectrometry (ICP/MS) is used to control heavy metals contamination in wine, and to verify the wine origin and authenticity. Isotopic ratio-mass spectrometry (IRMS) is applied to reveal wine watering and sugar additions, and to determine the product origin and traceability.

Concentrations and bioavailability of cadmium and lead in cocoa powder and related products

Concentrations and bioavailability of cadmium (Cd) and lead (Pb) were determined in cocoa powders and related products (beans, liquor, butter) of different geographical origins. Particular attention was paid to the fractionation of these metals, which was investigated by determining the metal fraction soluble in extractant solutions acting selectively with regard to the different classes of ligands. The targeted classes of Cd and Pb species included: water-soluble compounds, polypeptide and polysaccharide complexes, and compounds soluble in simulated gastrointestinal conditions. The bioavailability of Cd and Pb from cocoa powder, liquor and butter was evaluated using a sequential enzymolysis approach. The data obtained as a function of the geographical origin of the samples indicated strong differences not only in terms of the total Cd and Pb concentrations, but also with regard to the bioavailability of these metals. The Cd concentrations in the cocoa powders varied from 94 to 1833 microg kg(-1), of which 10-50% was potentially bioavailable. The bioavailability of Pb was generally below 10% and the concentrations measured in the cocoa powders were in the 11-769 microg kg(-1) range. Virtually all the Cd and most of Pb were found in the cocoa powder after the pressing of the liquor.

Monitoring the content and intake of trace elements from food in Denmark

The content of cadmium, lead, nickel, mercury and selenium in 83 foods was monitored from 1993 to 1997. In comparison with similar results from 1988 to 1992, a general decrease in lead levels had occurred, whereas the contents of cadmium, nickel, mercury and selenium were stable or declined only slightly. The distribution in dietary intake of the five trace elements was estimated by combining the mean trace element concentrations with food consumption data from 1837 Danes aged 15-80 years. The lead intake for 1993-97 showed a decrease in comparison with similar estimates from the previous monitoring cycles: 1983-87 and 1988-92. The intake of cadmium and mercury decreased to a lesser extent, whereas the intake of selenium and nickel remained unchanged in the same period. The dietary intake of trace elements was compared with the provisional tolerable weekly intake (PTWI). The 95th percentile of the distribution in cadmium intake amounts to 34% of PTWI, which is relatively high, and therefore calls for a more detailed future risk assessment. The intakes of lead and mercury were 11% of PTWI and, like the intake of nickel, did not cause any health concern in the adult population. The Danes ingest close to 100% of the Nordic Nutrition Recommendation for selenium at 50 microg day(-1), and no individuals had an intake less than the lower limit of 20 microg day(-1).

Assessment of metal content and toxicity of leachates from teapots

Metallic teapots traditionally used in Morocco were investigated for release of toxic metals from the teapots and their toxicity, as determined by MetPAD, a bacterial toxicity test that is specific for heavy metal toxicity. Our data show that some teapots were non-toxic while a few others were highly toxic, as shown by MetPAD. Tea addition reduced somewhat heavy metal toxicity due possibly to the complexing ability of tea. Chemical analysis of teapot leachates showed that some contained zinc and copper. Teapot No. 5, which showed the highest toxicity, also displayed the highest Zn concentration (7.39 mg/l), confirming the toxicity data. Based on estimates of tea consumption in Morocco, we showed that the extra daily burden of Zn ranged from 1.75 to 4.2 mg/day, assuming the maximum zinc concentration of 7.4 mg/l, as found in our study. This represents 3.5-8% of the LOAEL for zinc of 50 mg/day and would not be important as compared to other sources zinc intake.

Lead and cadmium in beverages consumed in Finland

The lead and cadmium contents of carbonated beverages, juices, beers and wines were determined by ETAAS using Zeeman background correction, peak height mode and the method of standard additions for quantitation. Other beverages were digested in conc. HNO3, but wines were diluted with 10% HNO3. The lead contents of beverages were negligible. The mean Pb content of juices was 9 micrograms/kg, 2 micrograms/kg in carbonated beverages, < 1 microgram/kg in mineral water and 3 and 4 micrograms/kg in domestic and imported beers. The mean lead content was 16 micrograms/l in domestic miscellaneous wines, 33 micrograms/l in imported white wines, 9 micrograms/l in domestic red wines and 34 micrograms/l in imported red wines. The cadmium contents in all beverages were < 1 microgram/kg, except for domestic red wine made from raspberry, which contained 2 micrograms/l. Beverages contribute only a negligible amount of lead and cadmium to the average Finnish diet. However, as the total lead intake is low in Finland, about 12 micrograms/day, the share of beverages is rather high, about a fifth of the total intake.