Estimation of the Bioaccessibility of Metallic Elements in Chocolate Drink Powder using an in vitro Digestion Method and Spectrometric Techniques

The bioaccessible fractions of Al, Ba, Cd, Cr, Cu, Mg, Mn and P in chocolate drink powder were estimated using an in vitro digestion method and spectrometric techniques. A three-step procedure was used as an in vitro digestion method, in which the digestive process occurring in the mouth, stomach and intestine are simulated with the preparation of synthetic digestive fluids. Mineralization assisted by microwave radiation was used for the treatment of the sample and the chyme (soluble portion) obtained in the in vitro digestion method, considering their high organic content. Aluminum, Ba, Cu, Mg, Mn and P were quantified by inductively coupled plasma optical emission spectrometry, whereas Cd and Cr were quantified by graphite furnace atomic absorption spectrometry. Considering the total content of these elements in chocolate drink powder, the bioaccessible fractions found were 5 +/- 3% for Al, 9 +/- 2% for Ba, 13 +/- 3% for Cd, 5 +/- 2% for Cr, 29 +/- 4% for Cu, 54 +/- 3% for Mg, 11 +/- 3% for Mn and 31 +/- 6% for P. In general, elements that perform essential functions in the human organism presented higher bioaccessibility when compared with potentially toxic elements at trace levels.