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Evaluation of chocolate as a source of dietary copper

June 2014
European Food Research and Technology 238(6):1063-1066

Authors:

University of Bern

Chocolate has frequently been proposed to be a valuable source of dietary copper, but data on the copper content of major contemporary chocolate brands are scarce. The copper content of 22 brands of chocolate, many of which are sold worldwide, is thus presented here. A reliable hot ashing procedure to determine the copper content of chocolate by inductively coupled plasma atomic emission spectroscopy is also described. It was found that the copper contents of the chocolates analyzed here varied in the range of 1.85 ± 0.10 to 16.50 ± 1.29 μg/g. There was a linear correlation of the copper content of chocolate to its cocoa content with a correlation coefficient R 2 of 0.89, showing that the copper was largely contributed to the chocolate by the cocoa. The value of chocolate as a source of dietary copper is discussed.

Relationship of copper content and cocoa content of chocolate. The copper content of 22 brands of chocolate was plotted against the cocoa content. The error bars show the standard deviations of at least three independent measurements. The linear regression exhibited a correlation of R 2 = 0.89

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Eur Food Res Technol (2014) 238:1063–1066

DOI 10.1007/s00217-014-2240-x

SHORT COMMUNICATION

Evaluation of chocolate as a source of dietary copper

Thomas Weber · Marc Solioz

Received: 4 February 2014 / Revised: 14 April 2014 / Accepted: 28 April 2014 / Published online: 10 May 2014

day recommended for grown-up, healthy adults [1]. Copper

intake beyond the DRI should probably be of no concern

for healthy adults. According to a recent study, a copper

intake of up to 8 mg/day for 6 months did not appear to

have any adverse effects in healthy individuals [2]. There

are, however, conditions in which excessive copper intake

may pose a risk, such as for individuals with Wilson dis-

ease, a genetic defect in copper secretion [24].

There is considerable debate of whether the DRI levels

are sufﬁcient and in fact, recommendations for adults in the

United Kingdom, the European Community, and Australia/

New Zealand are higher and range from 1.1 to 1.2 mg/day.

The required copper intake may vary a great deal depend-

ing on the source of the copper and the nutritional context,

both of which can affect the bioavailability (bioaccessibil-

ity) of the copper [3]. The focus in establishing nutritional

guidelines for copper and maximal tolerable copper levels

in drinking water has traditionally been placed on toxic-

ity rather than essentiality. Currently, there is concern that

some populations may be copper deﬁcient and this prob-

lem may be exacerbated in special circumstances, such as

in disease or following bariatric surgery, which is dramati-

cally on the rise [4–8].

The copper content of food varies over a wide range. It

is lowest in fats and oils, dairy products, sugar, tuna, and

lettuce (<0.4 μg/g). Higher copper levels are present in leg-

umes, mushrooms, chocolate, nuts, and seeds (>2.4 μg/g).

The best sources of copper are beef liver and oysters, which

typically contain 70–200 μg/g of copper [9, 10]. With the

increasing awareness in nutrition, particularly in the West-

ern world, people frequently turn to Internet sites for infor-

mation on nutritional aspects. As a good nutritional source

of copper, chocolate is often being recommended (e.g.,

http://www.healthaliciousness.com/articles/high-copper-

foods.php). On the other hand, liver and oysters are absent

Abstract Chocolate has frequently been proposed to be

a valuable source of dietary copper, but data on the copper

content of major contemporary chocolate brands are scarce.

The copper content of 22 brands of chocolate, many of

which are sold worldwide, is thus presented here. A reliable

hot ashing procedure to determine the copper content of

chocolate by inductively coupled plasma atomic emission

spectroscopy is also described. It was found that the copper

contents of the chocolates analyzed here varied in the range

of 1.85 ± 0.10 to 16.50 ± 1.29 μg/g. There was a linear

correlation of the copper content of chocolate to its cocoa

content with a correlation coefﬁcient R2 of 0.89, showing

that the copper was largely contributed to the chocolate by

the cocoa. The value of chocolate as a source of dietary

copper is discussed.

Keywords Chocolate · Copper content · Nutrition ·

Deﬁciency

Introduction

Copper is an essential micronutrient and functions as a

cofactor in over 30 enzymes in humans. The latest dietary

reference intakes (DRI) for copper range form 0.5 g/day for

infants to 1.3 mg/day for lactating women, with 0.9 mg/

T. Weber · M. Solioz (*)

Department Clinical Research, University of Bern, Murtenstrasse 35,

3010 Berne, Switzerland

e-mail: marc@solioz-scientiﬁc.ch

M. Solioz

Department of Plant Physiology and Biotechnology, Tomsk

State University, Prospect Lenina 36, 634050 Tomsk, Russian

Federation

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1064 Eur Food Res Technol (2014) 238:1063–1066

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in many recommendations for copper-rich foods, probably

due to the lack of tradition of eating these foods in some

countries.

Due to a lack of data on the copper content of contem-

porary chocolates, we here determined the copper content

of 22 major brands of chocolate by dry ashing and induc-

tively coupled plasma atomic emission spectroscopy (ICP–

AES). It was found that the copper content linearly corre-

lated with the cocoa content. Thus, cocoa-rich chocolates

should be recommended if chocolate is to serve as a source

of dietary copper.

Materials and methods

Different brands of chocolate were bought in local shops

and supermarkets in Berne, Switzerland, and stored at

room temperature. The cocoa content was taken either from

the product label or was inquired at the manufacturer. For

copper measurements, samples of 1–1.5 g of chocolate

were ashed in a kiln at 400 °C for 3 h and at 600 °C for

14 h. Fused silica crucibles (99.7 % Al2O3, Alsint, Faust

Laborbedarf AG, Schaffhausen, Switzerland) rather than

ceramic crucibles had to be used. Extensive experiments in

our laboratory had shown that standard ceramic crucibles

were unsuitable as they absorbed variable amounts of cop-

per, depending on the history of the crucibles. After cooling

of the ashed samples, the residues were dissolved in 1 ml

of 67 % HNO3 for 1 h under agitation. After addition of

1 ml of 30 % H2O2 and further incubation for 1 h at room

temperature, the sample was brought to a ﬁnal volume of

6 ml with water. This resulted in a clear solution without

insoluble residues. Copper concentrations were meas-

ured by ICP–AES, using a Jobin–Yvon JY 24 instrument

(HORIBA Jobin–Yvon GmbH, Munich, Germany) at a

wavelength of 324.754 nm and using Gauss integration for

0.5 min. The lower limit of detection for copper was ﬁve

parts per billion.

Results

A number of published methods were assessed in their

reliability to measure copper in chocolate. It was found

that published wet ashing procedures in mixtures of con-

centrated HNO3 and H2O2, or dry ashing at 500 °C gave

poor reproducibility across chocolates with widely dif-

fering cocoa and fat contents [11, 12]. These published

methods had been evaluated with standard reference mate-

rials, which were based on bovine liver or rice ﬂour sam-

ple matrices. However, these matrices are a poor reference

material for chocolate, which is rich in fats highly resistant

to wet oxidation. So, these published methods necessitate

ﬁltration or centrifugation of the samples. The dry ashing

procedure described here resulted in clear, residue-free

samples, which gave reproducible copper values across all

samples.

Table 1 shows the copper contents of 22 brands of choc-

olate. Many of the brands are marketed worldwide, while

a few are products speciﬁc to the Swiss market. The low-

est copper contents were found in two brands of white

chocolate, which are not chocolates in the strict sense of

the word, since they do not contain cocoa. They had cop-

per contents of 0.11 ± 0.05 and 1.02 ± 0.13 μg/g. For

the cocoa-containing chocolate brands, the copper values

ranged from 1.85 ± 0.10 to 16.50 ± 1.29 μg/g. Interest-

ingly, there was a very good, linear correlation between the

cocoa content and the copper content of chocolate brands

(R2 = 0.89), without any dramatic outliers (Fig. 1). This

suggests that the copper content of chocolate originates

largely from the cocoa. This is also supported by the two

white “chocolates”, which did not contain cocoa and exhib-

ited the lowest copper contents. Thus, the value of choco-

late as a source of dietary copper directly depends on the

cocoa content: Chocolates with a high cocoa content are

a better source of dietary copper than those with a low

content.

Discussion

The copper content of chocolate has not systematically

been addressed in the scientiﬁc literature. Although a num-

ber of reports deal with the copper content of chocolate and

other cocoa products such as chocolate drinks, cakes, etc.,

chocolate brands and cocoa contents were not given [8, 9,

12–16]. We thus saw a need to assess the copper content

of speciﬁc chocolate brands and relate them to the cocoa

content.

We here determined the copper content of 22 differ-

ent chocolates, many of which ﬁnd worldwide distribu-

tion today. There was a linear correlation between the

cocoa content of these chocolates and the copper content,

which ranged from 1.85 ± 0.10 μg/g of a chocolate con-

taining 31 % cocoa to 16.50 ± 1.29 μg/g of a chocolate

with 85 % cocoa. This clearly suggests that the copper is

contributed by the cocoa. Indeed, cocoa beans are high in

copper. The copper content of fermented cocoa beans from

Ghana was reported to range from 88 to 173 μg/g, depend-

ing on the length of pod storage [17]. How storage could

affect the copper content is hard to perceive and may reﬂect

a methodological problem. The copper content of cocoa

powder from local markets in Greece, Pakistan, and Brazil

ranged from 27 to 52 μg/g [12, 18, 19]. Hernandez et al.

[20] analyzed the copper, zinc, manganese, iron, and mag-

nesium content of primary chocolate mass from different

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1065Eur Food Res Technol (2014) 238:1063–1066

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manufacturers and found copper to vary between 11 and

27 μg/g. They concluded that the metal contents depended

on both, the origin of the cocoa beans and the grinding

and milling process, necessary to obtain a smooth choco-

late texture. Grinding and milling involves heavy equip-

ment and extended contact times of the cocoa mass with

various metal alloys. This can of course lead to enrich-

ment of the cocoa with metal ions. Raw cocoa beans from

plantations in Nigeria had a copper contents ranging from

104 to 642 μg/g [21]. According to the authors, the higher

copper contents were due to the use of copper sulfate for

disease prevention on these plantations. Clearly, cocoa in

various forms has an intrinsically high copper content. It

would be interesting to know how this relates to cocoa spe-

cies, origin, and growth conditions. However, in today’s

global markets, it has become impossible to track the origin

and species of the cocoa beans and chocolate producers are

unwilling or probably even unable to provide correspond-

ing information.

A majority of chocolates on the market have a cocoa

content in the range of 30–60 % and thus an average copper

content of around 4 μg/g. A typical 100 g bar of choco-

late thus contains 400 μg of copper and would contribute

44 % of the daily DRI for adults. On the other hand, 50 g of

chocolate high in cocoa would contribute 100 % of the DRI

for copper. In contrast to the copper content, the caloric

value of chocolate does not differ much between brands

and is around 5 kcal/g (21 kJ/g). If chocolate is considered

as a copper source, preference should clearly be given to

brands with a high cocoa and thus a high copper content to

minimize fat and energy intake.

According to an analysis of the eating habits of the

elderly in the USA in 2000, chocolate contributed only

12 % to the individual copper consumption [22]. This

implies the consumption of 5–40 g/day of chocolate,

Table 1 Copper and cocoa

content of different chocolate

brands

a STD, standard deviation

based on at least three

measurements

Nr. Chocolate brand Cocoa (%) Cu (μg/g) STDa (μg/g)

1 Lindt Excellence 70 12.14 1.04

2 Cailler Frigor Black 46 5.78 0.36

3 Cailler Frigor Milk 36 4.20 0.08

4 Lindt Excellence Prodigieux 90 15.28 1.17

5 Lindt Cresta Classic 30 2.64 0.13

6 Cailler Crémant Intense 64 10.80 0.47

7 Toblerone, legendary triangular chocolate 28 2.47 0.03

8 Lindt Excellence Puissant 85 16.50 1.29

9 Coop Prix Garantie chocolate with milk 30 2.42 0.10

10 Frey Giandor Noir 44 5.05 0.09

11 Coop Qualité & Prix Milk 31 1.85 0.10

12 Frey Milk Extra 31 2.37 0.10

13 Coop Qualité & Prix Les Classiques Crémant 60 7.51 0.39

14 Frey Noir Special 72 9.84 0.29

15 Criollo 1er Cru Orinoco 72 9.67 0.60

16 MBudget chocolate white 0 0.11 0.05

17 Wander Ovomaltine noir (Ovaltine) 60 6.91 0.47

18 MBudget milk chocolate 30 2.23 0.13

19 Suchard Marzipan 18 2.50 0.07

20 Frey Giandor milk chocolate with almond cream 37 3.58 0.30

21 Camille Bloch Torino 34 3.19 0.44

22 Frey Giandor White 0 1.02 0.13

R² = 0.8929

0 20406080100

Copper content [μg/g]

Cocoa content [%]

Fig. 1 Relationship of copper content and cocoa content of choco-

late. The copper content of 22 brands of chocolate was plotted against

the cocoa content. The error bars show the standard deviations of at

least three independent measurements. The linear regression exhib-

ited a correlation of R2 = 0.89

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1066 Eur Food Res Technol (2014) 238:1063–1066

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depending on the cocoa content. Chocolate is clearly a

good source of copper, and cocoa powder has successfully

been used to combat copper deﬁciency associated with tube

feeding in Japan [23]. Nevertheless, better sources for extra

copper would be beef liver or oysters, of which 5–15 g

would sufﬁce to provide the DRI and would be accompa-

nied by a lower fat and energy intake.

Chocolate contains several biologically active con-

stituents such as methylxanthines, biogenic amines, and

cannabinoid-like fatty acids, all of which are potentially

addictive substances. Indeed, excessive craving for choco-

late is a well-known phenomenon [25]. In addition, choco-

late has also been advocated as an antioxidant nutrient for

cardiovascular health [26]. These aspects are beyond the

realm of this discussion, but it should be noted that, aside

of its value as a copper source, chocolate remains a highly

interesting and enigmatic component of the human diet and

clearly deserves further research.

Acknowledgments This work was supported by Grant

CR32I3E-136073 from the Swiss National Science Foundation and a

Russian Federation Government Grant to leading scientists.

Conflict of interest None.

Compliance with Ethics Requirements This article does not con-

tain any studies with human or animal subjects.

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Apr 2022
J AOAC INT

Background: Chocolate is a rich source of essential and non-essential elements. A new liquid-liquid extraction approach, extraction induced by emulsion breaking (EIEB), is proposed in which the analyzed elements are transferred from the organic phase to the aqueous phase before measurement by flame atomic absorption spectrometry (FAAS). Objective: To compare EIEB to microwave digestion (MWD) for extraction of elements from chocolate prior to FAAS. Methods: EIEB parameters were varied to optimize the procedure. EIEB-FAAS was then compared to MWD-FAAS for the analysis of Ca, Cu, Fe, Mn, Ni, and Zn in milk and dark chocolate samples. A certified reference material (NIST 2384, baking chocolate) was analyzed to determine recoveries of Ca, Cu, Fe, Mn, and Zn by the two methods. Results: The optimized EIEB extraction method involves dilution of tempered chocolate with toluene, ultrasonic emulsification with acidified Triton X-114, breaking the emulsion by heating, and centrifugation to produce two well-defined phases. Analysis of dark and milk chocolate samples showed similar repeatability by EIEB-FAAS (RSDr 0.3 to 6.6% in dark and 0.5 to 8.7% in milk) and MWD-FAAS (RSDr 0.5 to 5.4% in dark and 0.7 to 10.2% in milk), with no significant difference detected between methods for analysis of Ca, Cu, Fe, Mn, Ni, and Zn based on Student's t-test. Analysis of NIST 2384 baking chocolate certified reference material for Ca, Cu, Fe, Mn, and Zn demonstrated recoveries of 98.6 to 99.5% for EIEB-FAAS compared to 95.8 to 98.6% for MWD-FAAS. Conclusion: EIEB-FAAS was shown to provide high recovery and excellent repeatability for accurate determination of Ca, Cu, Fe, Mn, Ni, and Zn from dark and milk chocolates. Highlight: The EIEB-FAAS method is simpler and requires fewer reagents compared to other sample preparation methods and allows the calibration to be carried out using aqueous calibration solutions.

A new method for calculating copper content and determining appropriate copper levels in foods

Article

Full-text available

Dec 2021
Rev Chil Nutr

Since the amount of food can affect the copper content, the copper content of different amounts of food (except foods without copper) is different. The copper content of some foods is inappropriately calculated per 100 kcal, 100 g or 100 mL, or the reference amount customarily consumed (RACC). Thus, making some food choices based on these calculations to achieve adequate copper intake may increase the risk of some chronic diseases. Calculating the copper content and determining appropriate copper levels (to achieve adequate copper intake) based on U.S. Food and Drug Administration (FDA), Codex Alimentarius Commission (CAC), and the proposed method were performed in 7,379 food items. Making some food choices based on the FDA and CAC per serving (the serving is derived from the RACC) or CAC per 100 g or 100 mL to achieve adequate copper intake exceeded energy needs, which could lead to overweight or obesity. Making some food choices based on the CAC per 100 kcal or CAC per 100 g or 100 mL to achieve adequate copper intake did not meet copper requirements, which could lead to copper deficiency. Some foods that met copper requirements were not appropriate food choices based on the CAC per 100 g or 100 mL or CAC per serving to achieve adequate copper intake. On the basis of the proposed method, calculating the copper content and determining appropriate copper levels in foods are performed by considering RACCs and the energy content of foods. Thus, making food choices based on the proposed method met copper requirements and did not exceed energy needs.

Simultaneous determination of cadmium, lead and copper in chocolate samples by square wave anodic stripping voltammetry

Article

Jan 2021

In this work, an effective and simple method is proposed for the simultaneous determination of cadmium, lead and copper in chocolate samples by Square Wave Anodic Stripping Voltammetry (SWASV). An ultrasonic bath was used for the extraction of cadmium, lead and copper from fourteen chocolate samples using HNO3 solution (7 mol L⁻¹). The electrochemical system consisted of a cell with three electrodes and HCl solution (10 mmol L⁻¹) as the supporting electrolyte. An efficient extraction of the metals (~100%) was attained after 1 h of ultrasonic pre-treatment. Quantitative analysis was carried out by the standard addition method. Good linearity, precision and accuracy were obtained in the range of concentrations examined. The accuracy was evaluated by means of a reference sample of spiked skim milk powder (BCR 151) to prove the reliability of the method. Detection limits (LOD) of 0.089, 0.059 and 0.018 µg g⁻¹ were found for cadmium, copper and lead, respectively, in the chocolate samples. Concentrations in chocolate samples were 4.30–138 µg g⁻¹ for Cu and 0.83–27.9 µg g⁻¹ for Pb, with no significant Cd. The simultaneous determination brings advantages to other methods already reported for chocolate analysis and the samples preparation proposed avoids the traditional sample mineralization step. These characteristics show this new method is especially attractive for case studies and routine analysis.

Escape from Quant Lab: Using Lab Skill Progression and a Final Project to Engage Students

Article

Jun 2021

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

Article

Full-text available

Jan 2015

A theme that emerges from this year's Update is that of ‘green’ chemistry. This, in part, explains the larger than usual number of publications focusing on sample preparation, especially those concerned with the analysis of foods. Procedures that involved dilute acids while still achieving digestion of the specimens were reported by various workers. Meanwhile the trend towards smaller and smaller volumes continues with developments on the microscale. These aspects were noted in both the original work and in reviews. Last year saw the large number of papers concerned with metallic prostheses and this topic continues to attract interest. In possibly the first publication in which ICP-MS/MS was used for a clinical application, concentrations of Ti were determined in serum from healthy subjects and patients with hip implants. Concern is evident over the toxicological implications of consumption of rice grown in regions where water is contaminated with As. This has led to several reports of analytical methods and of concentrations in foods and total diets. Localisation of the As into different parts of the plant and the rice was also investigated and, in some reports this included speciation as well as the total As concentrations. Compared with the last few years, Se longer dominates the speciation work reported in this Update and there are more reports relating to As and Hg. A new class of arsenolipids, cationic trimethylarsenio fatty alcohols, were discovered in Capelin Oil. The number of publications applying XRF spectrometry to imaging elements within tissues appears to be increasing with localisation in bone of particular interest. Laser ablation ICP-MS in combination with other techniques, TOF-SIMS, XRD or XPS was also noted, to increase the information obtained.

Atomic spectrometry update: Review of advances in the analysis of clinical and biological materials, foods and beverages

Article

Full-text available

Mar 2014

A theme that emerges from this year's Update is that of ‘green’ chemistry. This, in part, explains the larger than usual number of publications focussing on sample preparation, especially those concerned with the analysis of foods. Procedures that involved dilute acids while still achieving digestion of the specimens were reported by various workers. Meanwhile the trend towards smaller and smaller volumes continues with developments on the micro-scale. These aspects were noted in both the original work and in reviews. Last year saw the large number of papers concerned with metallic prostheses and this topic continues to attract interest. In possibly the first publication in which ICP-MS/MS was used for a clinical application, concentrations of Ti were determined in serum from healthy subjects and patients with hip implants. Concern is evident over the toxicological implications of consumption of rice grown in regions where water is contaminated with As. This has led to several reports of analytical methods and of concentrations in foods and total diets. Localisation of the As into different parts of the plant and the rice was also investigated and, in some reports this included speciation as well as the total As concentrations. Compared with the last few years, Se longer dominates the speciation work reported in this Update and there are more reports relating to As and Hg. A new class of arsenolipids, cationic trimethylarsenio fatty alcohols, were discovered in Capelin Oil. The number of publications applying XRF spectrometry to imaging elements within tissues appears to be increasing with localisation in bone of particular interest. Laser ablation ICP-MS in combination with other techniques, TOF-SIMS, XRD or XPS was also noted, to increase the information obtained.

Research Highlights

Article

Jun 2014
Lipid Tech

Copper Supplementation at 8 mg Neither Affects Circulating Lipids nor Liver Function in Apparently Healthy Chilean Men

Article

Full-text available

Oct 2013
BIOL TRACE ELEM RES

Unlabelled: Copper (Cu) deficiency has been reported to influence lipid metabolism, but the effects in humans are controversial. To evaluate the effects of 8 mg Cu/day supplementation (as copper sulfate) for 6 months on the lipid profile and hepatic function of apparently healthy men. The design was randomized double-blind placebo-controlled clinical trial. Subjects and methods: 60 apparently healthy males aged 18-51 years were randomly assigned to Cu supplementation (n = 30) or placebo (n = 30). There was a nonsignificant reduction of 17 % in total cholesterol in both groups after supplementation. A 23 % nonsignificant reduction was observed in LDL cholesterol levels in the supplemented group. There was a nonsignificant increase of HDL cholesterol of 47 and 66 % in the control and supplemented groups, respectively. Triglyceride levels over 150 mg/dl were found in 17 subjects supplemented and 13 controls at baseline and decreased after supplementation to seven and eight subjects, respectively. There were no effects on serum Cu concentration or ceruloplasmin (protein) and hepatic transaminases. Supplementation of 8 mg Cu for 6 months had no effect on lipid profile of apparently healthy Chilean men with adequate Cu status.

Mineral Malnutrition Following Bariatric Surgery

Article

Full-text available

Sep 2013

Moderate/severe obesity is on the rise in the United States. Weight management includes bariatric surgery, which is effective and can alleviate morbidity and mortality from obesity-associated diseases. However, many individuals are dealing with nutritional complications. Risk factors include: 1) preoperative malnutrition (e.g., vitamin D, iron); 2) decreased food intake (due to reduced hunger and increased satiety, food intolerances, frequent vomiting); 3) inadequate nutrient supplementation (due to poor compliance with multivitamin/multimineral regimen, insufficient amounts of vitamins and/or minerals in supplements); 4) nutrient malabsorption; and 5) inadequate nutritional support (due to lack of follow-up, insufficient monitoring, difficulty in recognizing symptoms of deficiency). For some nutrients (e.g., protein, vitamin B-12, vitamin D), malnutrition issues are reasonably addressed through patient education, routine monitoring, and effective treatment strategies. However, there is little attention paid to other nutrients (e.g., zinc, copper), which if left untreated may have devastating consequences (e.g., hair loss, poor immunity, anemia, defects in neuro-muscular function). This review focuses on malnutrition in essential minerals, including calcium (and vitamin D), iron, zinc, and copper, which commonly occur following popular bariatric procedures. There will be emphasis on the complexities, including confounding factors, related to screening, recognition of symptoms, and, when available, current recommendations for treatment. There is an exceptionally high risk of malnutrition in adolescents and pregnant women and their fetuses, who may be vulnerable to problems in growth and development. More research is required to inform evidence-based recommendations for improving nutritional status following bariatric surgery and optimizing weight loss, metabolic, and nutritional outcomes.

Fungicide-Derived Copper Content in Soil and Vegetation Component, Owena Cocoa ( Theobroma Cacao L.) Plantations in Nigeria

Article

Full-text available

Aug 2007

This work reported the results of copper content in the soil profiles of three different aged cocoa plantations subjected to copper- fungicide application and the various vegetational components (pod, beans, leaves, trunk bark, lateral root and twig). Soil copper at various depth considered ranged from 5.0 -42.0 μgg-1. Copper contents in both fresh and dry leaves of cocoa and banana were consistently high in all the three plantations. The copper contents ranged from 56-300μgg-1 (dry wt.) in cocoa trunk bark and 86-161μgg-1 in banana trunk bark. There was evidence of age-dependent accumulation of copper in cocoa pod and beans; hence it can be used to assess the degree of copper contamination. Copper contents from roots ranged from 408-2, 203μgg-1 (dry wt.). The soil did not appear contaminated by copper but alternative fungicide is recommended since copper accumulation in the cocoa beans was evident. Bangladesh J. Sci. Ind. Res. 41(3-4), 129-140, 2006

Comparison of digestion methods and trace elements determination in chocolates with pistachio using atomic absorption spectrometry

Article

Jan 2008
J FOOD NUTR RES

Metin Guldas

Digestion methods were validated using standard certified reference materials (BCR-185R, SRM-1577b and BCR-679). The microwave - assisted digestion was found the most reliable and accurate method for chocolate samples. The recovery rates were 96-102 %, 92-98 % and 90-96 % for the microwave digestion, the wet digestion and the dry ashing, respectively. The results obtained using certified reference materials were in a good agreement with certified values. Flame atomic absorption spectrometry (FAAS) was used for the determination of Fe, Cu, Zn, As and Fig. Graphite furnace atomic absorption spectrometry (GFAAS) was also used for the determination of Ni, Cd and Pb in chocolate with pistachio belonging to the same brand sold in different markets in Bursa, Turkey. In total, twelve chocolate samples were analysed for this purpose. Cu, Zn, Fe, Cd, Ni, Pb, As and Hg levels ranged from 9.15 to 10.61 mg..kg(-1), 14.05 to 16.68 mg.kg(-1), 2.31 to 3.67 mg.kg(-1), 0.01 to 0.03 mg.kg(-1), 0.33 to 1.52 mg.kg(-1), 0.001 to 0.04 mg.kg(-1), 0.004 to 0.02 mg.kg(-1) and 0.008 to 0.02 mg.kg(-1), respectively. The elemental contents of the analysed samples were within the ranges reported by the legal authorities for chocolate and other foods.

Discrimination de masses de cacao par l'utlisation de données chimiométriques: Détermination de leur origine géographique et de leur traitement technologique à partir des teneurs en cations métallique

Article

Jan 1994
Analusis

Determination of Cadmium, Lead, Copper and Arsenic in Raw Cocoa, Semifinished and Finished Chocolate Products

Article

Jan 1985

The levels of cadmium, lead, copper and arsenic were determined in two batches of raw cocoa and semifinished chocolate products sampled at various intermediate stages of the manufacturing process. The metal contents of eighteen chocolate bars produced by four chocolate making factories were also determined. A nalyses of the metal contents in cocoa containing samples were effected by dry ashing of the samples at 450°C, followed by inductively coupled plasma atomic emission spectrometry. Average recoveries of 90 to 97% were obtainedfor the metals when the samples were spiked with known concentrations of metals. The variations in the metal contents of raw cocoa, semi-finished and finished products show that there were no effective contaminations of metals during the manufacturing process; the amount of metals in the finished products corresponded to the fraction of cocoa mass present. The metal contents of locally produced chocolates were within acceptable levels except for arsenic which bordered on the limit.

Determination and comparison of some trace elements in different chocolate types produced in Turkey

Article

Jul 2008
J FOOD AGRIC ENVIRON

Different chocolate types belonging to plain chocolate, milk chocolate and chocolate with pistachio that were supplied from different markets in Bursa, Turkey were investigated for trace element contents. Determinations of mercury (Hg), arsenic (As), iron (Fe), copper (Cu) and zinc (Zn) were performed by using Flame Atomic Absorption Spectrometry (FAAS), while the other elements (lead (Pb), cadmium (Cd) and nickel (Ni)) were determined by Graphite Furnace Atomic Absorption Spectrometry (GFAAS). According to chocolate types, contents ranged from 0.03 to 0.04 (Pb), 0.02 to 0.04 (Hg), 0.02 to 0.03 (Cd), 0.01 to 0.02 (As), 1.29 to 4.78 (Ni), 5.74 to 10.61 (Cu), 2.52 to 3.67 (Fe) and 12.11 to 16.68 mg kg-1 (Zn), respectively. The levels of Cu, Zn and Fe were highest in chocolate with pistachio samples. The contents of Hg and Ni were highest in milk and plain chocolates, respectively. Arsenic (As) was highest in both chocolate types (milk chocolate and chocolate with pistachio). There was no difference among the chocolate types in terms of Pb and Cd contents (p<0.01). The heavy metal contents of the analyzed samples are within the ranges reported by the WHO and Turkish Food Codex regarding to chocolate and other foods.

Dietary reference values for vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium and zinc

Article

Jun 2003

Alan Shenkin

Copper intakes and consumption patterns of chocolate foods as sources of copper for individuals in the 1987–1988 Nationwide Food Consumption Survey

Article

Jan 1996
NUTR RES

Objectives of this study were to estimate mean daily intake of copper for eight age subgroups of each gender, to examine consumption patterns of chocolate foods in the U.S., and to determine amounts of copper provided by the consumption of chocolate foods by analyzing 3-day dietary records reported by individuals in the 1987–1988 Nationwide Food Consumption Survey. Mean daily copper intake for all age/gender groups of infants and children reached the lower value of the Estimated Safe and Adequate Daily Dietary Intake (ESADDI) range. However, the mean daily copper intake of all age/gender groups of adolescents and adults was below the ESADDI of 1.5 to 3.0 mg/day. Chocolate cookies were most frequently consumed among chocolate foods. Dark chocolate/candy made the highest contribution to mean daily copper intake (22.1% of ESADDI). Other major contributors to the daily copper intake were chocolate pie (17.8% of ESADDI), chocolate milk (13.3%), chocolate topping/syrup/icing (12.0%), milk chocolate/candy (11.3%), and chocolate cake/muffin (11.2%). The total dietary copper intake by males and females was positively associated (p<0.001) with the consumption of chocolate foods. These results indicate that the mean daily copper intake of American adolescents and adults is less than recommended level and chocolate foods can be a good source of American dietary copper.

The iron content of plant and animal foods

Article