Food Analytical Methods

, Volume 13, Issue 1, pp 195–202 | Cite as

Direct Analysis of Cocoa Powder, Chocolate Powder, and Powdered Chocolate Drink for Multi-element Determination by Energy Dispersive X-ray Fluorescence Spectrometry

  • Luciane B. Oliveira
  • Wagna P. C. dos Santos
  • Leonardo S. G. Teixeira
  • Maria Graças A. KornEmail author


The aim of this study was to evaluate the potential of applying energy dispersive X-ray fluorescence (EDXRF) spectrometry to determine Ca, K, P, Mg, Fe, Zn, Cu, Mn, and Al concentrations for direct analysis of cocoa powder, chocolate powder, and powdered chocolate drink samples. The proposed method was calibrated using samples previously analyzed by inductively coupled plasma optical emission spectrometry (ICP OES). For comparison purposes, the samples were also analyzed by ICP OES after an acid digestion procedure, and no significant differences were observed between the concentrations determined by EDXRF when compared to those by ICP OES. The coefficients of correlation (R) from the calibration curves and the limit of quantification (mg kg−1) were Ca (0.996, 0.030), K (0.985, 68), Mg (0.974, 0.020), P (0.986, 0.50), Mn (0.998, 3.6), Fe (0.981, 2.5), Cu (0.978, 1.3), Zn (0.996, 0.80), and Al (0.983, 7.5). The precisions obtained for the elements were between 1.5 and 7.8% (n = 7), indicating that the preparation of the pellets was efficient to perform analysis by EDXRF. Potassium was the macro-mineral with higher concentrations in the samples. In relation to the micro-minerals, Fe had the greatest concentration. Significant concentrations of Al were also found. It was found that, in general, samples of chocolate powder and powdered chocolate drink may be considered good sources for the ingestion of Mg, Mn, Ca, K, P, Fe, Zn, and Cu.


Cocoa powder Chocolate powder Powdered chocolate drink Inorganic constituents Direct analysis EDXRF 


Funding Information

The authors are supported granted by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil) and Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB, Brazil) for providing grants, fellowships, and other financial support. This study also was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001.

Compliance with Ethical Standards

Conflict of Interest

Luciane B. Oliveira declares that she has no conflict of interest. Wagna P. C. dos Santos declares that she has no conflict of interest. Leonardo S. G. Teixeira declares that he has no conflict of interest. Maria Graças A. Korn declares that she has no conflict of interest.

Ethical Approval

This article does not contain any studies involving human participants or animals performed by any of the authors.

Informed Consent

Not applicable.

Supplementary material

12161_2019_1565_MOESM1_ESM.docx (31 kb)
ESM 1 (DOCX 31 kb)


  1. Andrey D, Dufrier JP, Perring L (2018) Analytical capabilities of energy dispersive X-ray fluorescence for the direct quantification of iron in cocoa powder and powdered cocoa drink. Spectrochim Acta B At Spectrosc 148:137–142CrossRefGoogle Scholar
  2. Association of official analytical chemists international - AOAC (2016) Guidelines for Standard Method Performance Requirements. Appendix F, p. 2–18Google Scholar
  3. Bartos A, Majak I, Leszczyńska J (2014) Uptake and assimilability of nickel in the course of systemic allergy: implications for elimination diet. Food Res Int 55:412–417CrossRefGoogle Scholar
  4. Bertin EP (2012) Principles and practice of X-ray spectrometric analysis. Springer Science & Business MediaGoogle Scholar
  5. Bondy SC (2014) Prolonged exposure to low levels of aluminum leads to changes associated with brain aging and neurodegeneration. Toxicology 315:1–7PubMedCrossRefGoogle Scholar
  6. Brito GB, Teixeira LSG, Korn MGA (2017) Direct analysis of marine macroalgae for determination of macro minerals by energy dispersive X-ray fluorescence. Microchem J 134:35–40CrossRefGoogle Scholar
  7. Costa VC, Amorim FAC, Babos DV, Pereira-Filho ER (2019) Direct determination of ca, K, mg, Na, P, S, Fe and Zn in bivalve mollusks by wavelength dispersive X-ray fluorescence (WDXRF) and laser-induced breakdown spectroscopy (LIBS). Food Chem 273:91–98PubMedCrossRefGoogle Scholar
  8. Crozier SJ, Preston AG, Hurst JW, Payne MJ, Mann J, Hainly L, Miller DL (2011) Cacao seeds are a" super fruit": a comparative analysis of various fruit powders and products. Chem Cent J 5(1):5PubMedPubMedCentralCrossRefGoogle Scholar
  9. Gallardo H, Queralt I, Tapias J, Guerra M, Carvalho ML, Marguí E (2016) Possibilities of low-power X-ray fluorescence spectrometry methods for rapid multielemental analysis and imaging of vegetal foodstuffs. J Food Compos Anal 50:1–9CrossRefGoogle Scholar
  10. Gothankar SS, Jha SK, Lenka P, Tripathi RM, Puranik VD (2009) Daily intake of manganese by local population around Kylleng Pyndengsohiong Mawthabah (Domiasiat), Meghalaya in India. Sci Total Environ 407(8):2868–2871PubMedCrossRefGoogle Scholar
  11. Hartwig A, Jahnke G (2017) Metalle und ihre Verbindungen als Kontaminanten in Lebensmitteln. Bundesgesundheitsblatt-Gesundheitsforschung-Gesundheitsschutz 60(7):715–721PubMedCrossRefGoogle Scholar
  12. Hartwig CA, Pereira RM, Rondan FS, Cruz SM, Duarte FA, Flores EM, Mesko MF (2016) The synergic effect of microwave and ultraviolet radiation for chocolate digestion and further determination of as, cd, Ni and Pb by ICP-MS. J Anal At Spectrom 31(2):523–530CrossRefGoogle Scholar
  13. Herreros-Chavez L, Cervera ML, Morales-Rubio A (2019) Direct determination by portable ED-XRF of mineral profile in cocoa powder samples. Food Chem 278:373–379PubMedCrossRefGoogle Scholar
  14. Jenkins R (1995) Quantitative X-ray spectrometry. CRC PressGoogle Scholar
  15. Kaur J, and Kumar A (2016) Elemental analysis of different varieties of rice samples using XRF technique. In AIP Conference Proceedings AIP Publishing 1728: 020350Google Scholar
  16. Krug, F and Rocha, F. (2016). Métodos de Preparo de Amostras/Fundamentos sobre preparo de amostras orgânicas e inorgânicas para análise elementar 1ª ed. Piracicaba: Ed.: CENA/USPGoogle Scholar
  17. Mir-Marqués A, Martínez-García M, Garrigues S, Cervera ML, de la Guardia M (2016) Green direct determination of mineral elements in artichokes by infrared spectroscopy and X-ray fluorescence. Food Chem 196:1023–1030PubMedCrossRefGoogle Scholar
  18. Mohapatra A, Rautray TR, Patra AK, Vijayan V, Mohanty RK (2009) Trace element-based food value evaluation in soft and hard shelled mud crabs. Food Chem Toxicol 47(11):2730–2734PubMedCrossRefGoogle Scholar
  19. Noda T, Tsuda S, Mori M, Takigawa S, Matsuura-Endo C, Kim SJ et al (2006) Determination of the phosphorus content in potato starch using an energy-dispersive X-ray fluorescence method. Food Chem 95(4):632–637CrossRefGoogle Scholar
  20. Otaka A, Hokura A, Nakai I (2014) Determination of trace elements in soybean by X-ray fluorescence analysis and its application to identification of their production areas. Food Chem 147:318–326PubMedCrossRefGoogle Scholar
  21. Paltridge NG, Milham PJ, Ortiz-Monasterio JI, Velu G, Yasmin Z, Palmer LJ et al (2012) Energy-dispersive X-ray fluorescence spectrometry as a tool for zinc, iron and selenium analysis in whole grain wheat. Plant Soil 361(1–2):261–269CrossRefGoogle Scholar
  22. Peixoto RR, Mazon EA, Cadore S (2013) Estimation of the bioaccessibility of metallic elements in chocolate drink powder using an in vitro digestion method and spectrometric techniques. J Braz Chem Soc 24(5):884–890Google Scholar
  23. Peixoto RR, Devesa V, Vélez D, Cervera ML, Cadore S (2016) Study of the factors influencing the bioaccessibility of 10 elements from chocolate drink powder. J Food Compos Anal 48:41–47CrossRefGoogle Scholar
  24. Peruchi, L. C., Nunes, L. C., de Carvalho, G. G. A., Guerra, M. B. B., de Almeida, E., Rufini, I. A., .and Krug, F. J. (2014). Determination of inorganic nutrients in wheat flour by laser-induced breakdown spectroscopy and energy dispersive X-ray fluorescence spectrometry. Spectrochim Acta B At Spectrosc 100: 129–136CrossRefGoogle Scholar
  25. Preedy VR, Zibadi S (2013) In: Watson RR (ed) Chocolate in health and nutrition. Humana Press, LondonGoogle Scholar
  26. Pytlakowska K (2016a) Graphene-based preconcentration system prior to energy dispersive x-ray fluorescence spectrometric determination of co, Ni, and cu ions in wine samples. Food Anal Methods 9(8):2270–2279CrossRefGoogle Scholar
  27. Pytlakowska K (2016b) 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. Appl Spectrosc 70(11):1891–1899PubMedCrossRefGoogle Scholar
  28. Ramtahal G, Yen IC, Bekele I, Bekele F, Wilson L, Sukha B, Maharaj K (2015) Cost-effective method of analysis for the determination of cadmium, copper, nickel and zinc in cocoa beans and chocolates. J Food Res 4(1):193CrossRefGoogle Scholar
  29. Sager M (2012) Chocolate and cocoa products as a source of essential elements in nutrition. J Nutr Food Sci 2:1–10Google Scholar
  30. Ščančar J, Zuliani T, Milačič R (2013) Study of nickel content in Ni-rich food products in Slovenia. J Food Compos Anal 32(1):83–89CrossRefGoogle Scholar
  31. Smoliński A, Stempin M, Howaniec N (2016) Determination of rare earth elements in combustion ashes from selected polish coal mines by wavelength dispersive X-ray fluorescence spectrometry. Spectrochim Acta B At Spectrosc 116:63–74CrossRefGoogle Scholar
  32. Syahfitri WYN, Kurniawati S, Adventini N, Damastuti E, Lestiani DD (2017) Macro elemental analysis of food samples by nuclear analytical technique. J Phys Conf Ser IOP Publish 860:012023CrossRefGoogle Scholar
  33. Thomsen V, Roberts G, Burgess K (2000) The concept of background equivalent concentration in spectrochemistry. Spectroscopy 15(1):33Google Scholar
  34. Van Grieken R, Markowicz A (eds) (2001) Handbook of X-ray spectrometry. CRC pressGoogle Scholar
  35. Villa JE, Peixoto RR, Cadore S (2014) Cadmium and lead in chocolates commercialized in Brazil. J Agric Food Chem 62(34):8759–8763PubMedCrossRefGoogle Scholar
  36. Villa JE, Pereira CD, Cadore S (2015) A novel, rapid and simple acid extraction for multielemental determination in chocolate bars. Microchem J 121:199–204CrossRefGoogle Scholar
  37. Yanus RL, Sela H, Borojovich EJ, Zakon Y, Saphier M, Nikolski A, Gutflais E, Lorber A, Karpas Z (2014) Trace elements in cocoa solids and chocolate: an ICPMS study. Talanta 119:1–4PubMedCrossRefGoogle Scholar
  38. Yeh TS, Liu YT, Liou PJ, Li HP, Chen CC (2016) Investigation of aluminum content of imported candies and snack foods in Taiwan. J Food Drug Anal 24(4):771–779PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Instituto de Química, Departamento de Química AnalíticaUniversidade Federal da BahiaSalvadorBrazil
  2. 2.Instituto Federal de AlagoasPenedoBrazil
  3. 3.Departamento de QuímicaInstituto Federal de Educação, Ciência e Tecnologia da BahiaSalvadorBrazil
  4. 4.INCT de Energia e Ambiente-Universidade Federal da BahiaInstituto de QuímicaSalvadorBrazil

Personalised recommendations