X-RAY FLUORESCENCE AND GAMMA-RAY SPECTROMETRY FOR MACRO AND MICRONUTRIENTS FROM SOUTH AMERICAN COFFEE POWDER

The study proposed in this paper aims to analyze the macro and micronutrients in samples of South American Coffee powder, in 2 different stages of coffee preparation, before and after (coffee ground) the extraction beverage, which is commonly consumed by most people in South American countries [1]. In the analyzed samples the concentrations of the main elements, it were quantify the presence of K, Rb, Ca, Cl, S, Sr and Fe elements in coffee powder and grounds from South America regions were measured using Energy Dispersive X-ray fluorescence (ED-XRF) and -ray spectrometry analysis. We also investigated the presence of 40K and the radionuclides from the uranium and thorium series decays using the gamma-ray spectrometry method [2]. The knowledge of the presence of macro- and micronutrients, as well as radionuclides present in food, is very important to humans. In the study on coffee powder, it is worth mentioning that the Brazilian annual consumption is higher than 20 million bags of 60 kg, according to the Brazilian Association of Coffee Industry (ABIC) [3]. The beverage obtained after the extraction was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICPMS). With the results obtained using these three techniques, it was possible to estimate ingestion index for each natural radioisotope, macro and micronutrient concentrations identified in the coffee samples. In Figure 1 the identification of the micro nutrients in coffee grounds and powder, in ppm concentration, using a filtered X-Ray technique was shown evidencing the capability of the technique. Preliminary results show that the annual dose due to the coffee ingestion in Brazil reaches 1.96(4) mSv, depending on the origin of the coffee. The elements transferred to the coffee beverage are mainly Cl, K and Rb. The concentration of Fe in coffee powder is around 250 ppm.